Fast and extensible multi-platform HTTP/1-2-3 web server with automatic HTTPS
Mirrored from https://github.com/Slazee/caddy.git
Synced Nov 11, 01:00 UTC
| 1 | // Copyright 2015 Matthew Holt and The Caddy Authors |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package reverseproxy |
| 16 | |
| 17 | import ( |
| 18 | "bytes" |
| 19 | "context" |
| 20 | "crypto/rand" |
| 21 | "encoding/base64" |
| 22 | "encoding/json" |
| 23 | "errors" |
| 24 | "fmt" |
| 25 | "io" |
| 26 | "maps" |
| 27 | "net" |
| 28 | "net/http" |
| 29 | "net/http/httptrace" |
| 30 | "net/netip" |
| 31 | "net/textproto" |
| 32 | "net/url" |
| 33 | "slices" |
| 34 | "strconv" |
| 35 | "strings" |
| 36 | "sync" |
| 37 | "sync/atomic" |
| 38 | "time" |
| 39 | |
| 40 | "github.com/dunglas/httpsfv" |
| 41 | "github.com/quic-go/quic-go/http3" |
| 42 | "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp" |
| 43 | "go.opentelemetry.io/contrib/propagators/autoprop" |
| 44 | oteltrace "go.opentelemetry.io/otel/trace" |
| 45 | "go.uber.org/zap" |
| 46 | "go.uber.org/zap/zapcore" |
| 47 | "golang.org/x/net/http/httpguts" |
| 48 | |
| 49 | "github.com/caddyserver/caddy/v2" |
| 50 | "github.com/caddyserver/caddy/v2/caddyconfig/caddyfile" |
| 51 | "github.com/caddyserver/caddy/v2/modules/caddyevents" |
| 52 | "github.com/caddyserver/caddy/v2/modules/caddyhttp" |
| 53 | "github.com/caddyserver/caddy/v2/modules/caddyhttp/headers" |
| 54 | "github.com/caddyserver/caddy/v2/modules/caddyhttp/rewrite" |
| 55 | ) |
| 56 | |
| 57 | // inFlightRequests uses sync.Map with atomic.Int64 for lock-free updates on the hot path |
| 58 | var inFlightRequests sync.Map |
| 59 | |
| 60 | func incInFlightRequest(address string) { |
| 61 | v, _ := inFlightRequests.LoadOrStore(address, new(atomic.Int64)) |
| 62 | v.(*atomic.Int64).Add(1) |
| 63 | } |
| 64 | |
| 65 | func decInFlightRequest(address string) { |
| 66 | if v, ok := inFlightRequests.Load(address); ok { |
| 67 | if v.(*atomic.Int64).Add(-1) <= 0 { |
| 68 | inFlightRequests.Delete(address) |
| 69 | } |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | func getInFlightRequests() map[string]int64 { |
| 74 | copyMap := make(map[string]int64) |
| 75 | inFlightRequests.Range(func(key, value any) bool { |
| 76 | copyMap[key.(string)] = value.(*atomic.Int64).Load() |
| 77 | return true |
| 78 | }) |
| 79 | return copyMap |
| 80 | } |
| 81 | |
| 82 | func init() { |
| 83 | caddy.RegisterModule(Handler{}) |
| 84 | } |
| 85 | |
| 86 | // Handler implements a highly configurable and production-ready reverse proxy. |
| 87 | // |
| 88 | // Upon proxying, this module sets the following placeholders (which can be used |
| 89 | // both within and after this handler; for example, in response headers): |
| 90 | // |
| 91 | // Placeholder | Description |
| 92 | // ------------|------------- |
| 93 | // `{http.reverse_proxy.upstream.address}` | The full address to the upstream as given in the config |
| 94 | // `{http.reverse_proxy.upstream.hostport}` | The host:port of the upstream |
| 95 | // `{http.reverse_proxy.upstream.host}` | The host of the upstream |
| 96 | // `{http.reverse_proxy.upstream.port}` | The port of the upstream |
| 97 | // `{http.reverse_proxy.upstream.requests}` | The approximate current number of requests to the upstream |
| 98 | // `{http.reverse_proxy.upstream.max_requests}` | The maximum approximate number of requests allowed to the upstream |
| 99 | // `{http.reverse_proxy.upstream.fails}` | The number of recent failed requests to the upstream |
| 100 | // `{http.reverse_proxy.upstream.latency}` | How long it took the proxy upstream to write the response header. |
| 101 | // `{http.reverse_proxy.upstream.latency_ms}` | Same as 'latency', but in milliseconds. |
| 102 | // `{http.reverse_proxy.upstream.duration}` | Time spent proxying to the upstream, including writing response body to client. |
| 103 | // `{http.reverse_proxy.upstream.duration_ms}` | Same as 'upstream.duration', but in milliseconds. |
| 104 | // `{http.reverse_proxy.duration}` | Total time spent proxying, including selecting an upstream, retries, and writing response. |
| 105 | // `{http.reverse_proxy.duration_ms}` | Same as 'duration', but in milliseconds. |
| 106 | // `{http.reverse_proxy.retries}` | The number of retries actually performed to communicate with an upstream. |
| 107 | type Handler struct { |
| 108 | // Configures the method of transport for the proxy. A transport |
| 109 | // is what performs the actual "round trip" to the backend. |
| 110 | // The default transport is plaintext HTTP. |
| 111 | TransportRaw json.RawMessage `json:"transport,omitempty" caddy:"namespace=http.reverse_proxy.transport inline_key=protocol"` |
| 112 | |
| 113 | // A circuit breaker may be used to relieve pressure on a backend |
| 114 | // that is beginning to exhibit symptoms of stress or latency. |
| 115 | // By default, there is no circuit breaker. |
| 116 | CBRaw json.RawMessage `json:"circuit_breaker,omitempty" caddy:"namespace=http.reverse_proxy.circuit_breakers inline_key=type"` |
| 117 | |
| 118 | // Load balancing distributes load/requests between backends. |
| 119 | LoadBalancing *LoadBalancing `json:"load_balancing,omitempty"` |
| 120 | |
| 121 | // Health checks update the status of backends, whether they are |
| 122 | // up or down. Down backends will not be proxied to. |
| 123 | HealthChecks *HealthChecks `json:"health_checks,omitempty"` |
| 124 | |
| 125 | // Upstreams is the static list of backends to proxy to. |
| 126 | Upstreams UpstreamPool `json:"upstreams,omitempty"` |
| 127 | |
| 128 | // A module for retrieving the list of upstreams dynamically. Dynamic |
| 129 | // upstreams are retrieved at every iteration of the proxy loop for |
| 130 | // each request (i.e. before every proxy attempt within every request). |
| 131 | // Active health checks do not work on dynamic upstreams, and passive |
| 132 | // health checks are only effective on dynamic upstreams if the proxy |
| 133 | // server is busy enough that concurrent requests to the same backends |
| 134 | // are continuous. Instead of health checks for dynamic upstreams, it |
| 135 | // is recommended that the dynamic upstream module only return available |
| 136 | // backends in the first place. |
| 137 | DynamicUpstreamsRaw json.RawMessage `json:"dynamic_upstreams,omitempty" caddy:"namespace=http.reverse_proxy.upstreams inline_key=source"` |
| 138 | |
| 139 | // Adjusts how often to flush the response buffer. By default, |
| 140 | // no periodic flushing is done. A negative value disables |
| 141 | // response buffering, and flushes immediately after each |
| 142 | // write to the client. This option is ignored when the upstream's |
| 143 | // response is recognized as a streaming response, or if its |
| 144 | // content length is -1; for such responses, writes are flushed |
| 145 | // to the client immediately. |
| 146 | FlushInterval caddy.Duration `json:"flush_interval,omitempty"` |
| 147 | |
| 148 | // A list of IP ranges (supports CIDR notation) from which |
| 149 | // X-Forwarded-* header values should be trusted. By default, |
| 150 | // no proxies are trusted, so existing values will be ignored |
| 151 | // when setting these headers. If the proxy is trusted, then |
| 152 | // existing values will be used when constructing the final |
| 153 | // header values. |
| 154 | TrustedProxies []string `json:"trusted_proxies,omitempty"` |
| 155 | |
| 156 | // Headers manipulates headers between Caddy and the backend. |
| 157 | // By default, all headers are passed-thru without changes, |
| 158 | // with the exceptions of special hop-by-hop headers. |
| 159 | // |
| 160 | // X-Forwarded-For, X-Forwarded-Proto and X-Forwarded-Host |
| 161 | // are also set implicitly. |
| 162 | Headers *headers.Handler `json:"headers,omitempty"` |
| 163 | |
| 164 | // If nonzero, the entire request body up to this size will be read |
| 165 | // and buffered in memory before being proxied to the backend. This |
| 166 | // should be avoided if at all possible for performance reasons, but |
| 167 | // could be useful if the backend is intolerant of read latency or |
| 168 | // chunked encodings. An incremental request with an explicitly configured |
| 169 | // buffer receives a 501 response. A transport-supplied default is bypassed |
| 170 | // only when the request already meets the transport's framing requirements. |
| 171 | RequestBuffers int64 `json:"request_buffers,omitempty"` |
| 172 | |
| 173 | // If nonzero, the entire response body up to this size will be read |
| 174 | // and buffered in memory before being proxied to the client. This |
| 175 | // should be avoided if at all possible for performance reasons, but |
| 176 | // could be useful if the backend has tighter memory constraints. Forwarding |
| 177 | // an incremental response with content produces a 501 response whenever |
| 178 | // buffering is configured. |
| 179 | ResponseBuffers int64 `json:"response_buffers,omitempty"` |
| 180 | |
| 181 | // The name identifying this proxy in the Proxy-Status response header |
| 182 | // field (RFC 9209). It has to identify the deployment rather than the |
| 183 | // software, so there is no sensible default: a service name |
| 184 | // ("ExampleCDN"), a hostname ("proxy-3.example.com") or an IP address |
| 185 | // are all appropriate. This is used when Caddy refuses to forward a |
| 186 | // message marked Incremental. When empty, no Proxy-Status field is generated. |
| 187 | ProxyStatusName string `json:"proxy_status_name,omitempty"` |
| 188 | |
| 189 | // If nonzero, streaming requests such as WebSockets will be |
| 190 | // forcibly closed at the end of the timeout. Default: no timeout. |
| 191 | StreamTimeout caddy.Duration `json:"stream_timeout,omitempty"` |
| 192 | |
| 193 | // The size of the buffer used for each direction of streaming |
| 194 | // requests such as WebSockets. If zero, the default size is 32 KiB. |
| 195 | // This only affects upgraded bidirectional streams, not normal |
| 196 | // request or response buffering. |
| 197 | StreamBufferSize int `json:"stream_buffer_size,omitempty"` |
| 198 | |
| 199 | // If nonzero, streaming requests such as WebSockets will not be |
| 200 | // closed when the proxy config is unloaded, and instead the stream |
| 201 | // will remain open until the delay is complete. In other words, |
| 202 | // enabling this prevents streams from closing when Caddy's config |
| 203 | // is reloaded. Enabling this may be a good idea to avoid a thundering |
| 204 | // herd of reconnecting clients which had their connections closed |
| 205 | // by the previous config closing. Default: no delay. |
| 206 | StreamCloseDelay caddy.Duration `json:"stream_close_delay,omitempty"` |
| 207 | |
| 208 | // If true, upgraded connections such as WebSockets are detached from |
| 209 | // the handler and retained across config reloads when their upstream |
| 210 | // still exists in the new config. Connections using upstreams that are |
| 211 | // removed are closed during cleanup. By default this is false, preserving |
| 212 | // legacy behavior where upgraded connections are closed on reload |
| 213 | // (optionally delayed by stream_close_delay). |
| 214 | // Only http1.1 websocket connections are affected, websockets for h2/h3 |
| 215 | // are not affected. If true, bytes transferred for http1.1 in the access |
| 216 | // logs will be zero but those stats can be found in the stream logs for |
| 217 | // http1/2/3 regardless if this is enabled. |
| 218 | StreamDetached bool `json:"stream_detached,omitempty"` |
| 219 | |
| 220 | // Controls logging behavior for upgraded stream lifecycle events. |
| 221 | // If omitted, defaults are used (level=DEBUG, logger_name="http.handlers.reverse_proxy.stream"). |
| 222 | StreamLogs *StreamLogs `json:"stream_logs,omitempty"` |
| 223 | |
| 224 | // If configured, rewrites the copy of the upstream request. |
| 225 | // Allows changing the request method and URI (path and query). |
| 226 | // Since the rewrite is applied to the copy, it does not persist |
| 227 | // past the reverse proxy handler. |
| 228 | // If the method is changed to `GET` or `HEAD`, the request body |
| 229 | // will not be copied to the backend. This allows a later request |
| 230 | // handler -- either in a `handle_response` route, or after -- to |
| 231 | // read the body. |
| 232 | // By default, no rewrite is performed, and the method and URI |
| 233 | // from the incoming request is used as-is for proxying. |
| 234 | Rewrite *rewrite.Rewrite `json:"rewrite,omitempty"` |
| 235 | |
| 236 | // List of handlers and their associated matchers to evaluate |
| 237 | // after successful roundtrips. The first handler that matches |
| 238 | // the response from a backend will be invoked. The response |
| 239 | // body from the backend will not be written to the client; |
| 240 | // it is up to the handler to finish handling the response. |
| 241 | // If passive health checks are enabled, any errors from the |
| 242 | // handler chain will not affect the health status of the |
| 243 | // backend. |
| 244 | // |
| 245 | // Three new placeholders are available in this handler chain: |
| 246 | // - `{http.reverse_proxy.status_code}` The status code from the response |
| 247 | // - `{http.reverse_proxy.status_text}` The status text from the response |
| 248 | // - `{http.reverse_proxy.header.*}` The headers from the response |
| 249 | HandleResponse []caddyhttp.ResponseHandler `json:"handle_response,omitempty"` |
| 250 | |
| 251 | // If set, the proxy will write very detailed logs about its |
| 252 | // inner workings. Enable this only when debugging, as it |
| 253 | // will produce a lot of output. |
| 254 | // |
| 255 | // EXPERIMENTAL: This feature is subject to change or removal. |
| 256 | VerboseLogs bool `json:"verbose_logs,omitempty"` |
| 257 | |
| 258 | Transport http.RoundTripper `json:"-"` |
| 259 | CB CircuitBreaker `json:"-"` |
| 260 | DynamicUpstreams UpstreamSource `json:"-"` |
| 261 | |
| 262 | // transportHeaderOps is a set of header operations provided |
| 263 | // by the transport at provision time, if the transport |
| 264 | // implements TransportHeaderOpsProvider. These ops are |
| 265 | // applied before any user-configured header ops so the |
| 266 | // user can override transport defaults. |
| 267 | transportHeaderOps *headers.HeaderOps |
| 268 | |
| 269 | // requestBuffersFromTransport distinguishes a transport default from an |
| 270 | // operator-configured buffer. Incremental forwarding may bypass the former |
| 271 | // only when the request already meets the transport's framing requirements. |
| 272 | requestBuffersFromTransport bool |
| 273 | |
| 274 | // Holds the parsed CIDR ranges from TrustedProxies |
| 275 | trustedProxies []netip.Prefix |
| 276 | |
| 277 | // Holds the named response matchers from the Caddyfile while adapting |
| 278 | responseMatchers map[string]caddyhttp.ResponseMatcher |
| 279 | |
| 280 | // Holds the handle_response Caddyfile tokens while adapting |
| 281 | handleResponseSegments []*caddyfile.Dispenser |
| 282 | |
| 283 | // Tracks hijacked/upgraded connections (WebSocket etc.) so they can be |
| 284 | // closed when their upstream is removed from the config. |
| 285 | tunnelTracker *tunnelTracker |
| 286 | |
| 287 | // tracedTransport wraps Transport to emit OpenTelemetry client spans |
| 288 | // for upstream round trips when the request is being traced. |
| 289 | tracedTransport http.RoundTripper |
| 290 | |
| 291 | ctx caddy.Context |
| 292 | logger *zap.Logger |
| 293 | events *caddyevents.App |
| 294 | |
| 295 | streamLogLevel zapcore.Level |
| 296 | streamLogLoggerName string |
| 297 | } |
| 298 | |
| 299 | // CaddyModule returns the Caddy module information. |
| 300 | func (Handler) CaddyModule() caddy.ModuleInfo { |
| 301 | return caddy.ModuleInfo{ |
| 302 | ID: "http.handlers.reverse_proxy", |
| 303 | New: func() caddy.Module { return new(Handler) }, |
| 304 | } |
| 305 | } |
| 306 | |
| 307 | // Provision ensures that h is set up properly before use. |
| 308 | func (h *Handler) Provision(ctx caddy.Context) error { |
| 309 | eventAppIface, err := ctx.App("events") |
| 310 | if err != nil { |
| 311 | return fmt.Errorf("getting events app: %v", err) |
| 312 | } |
| 313 | h.events = eventAppIface.(*caddyevents.App) |
| 314 | h.ctx = ctx |
| 315 | h.logger = ctx.Logger() |
| 316 | h.tunnelTracker = newTunnelTracker(h.logger, time.Duration(h.StreamCloseDelay)) |
| 317 | h.streamLogLevel = defaultStreamLogLevel |
| 318 | h.streamLogLoggerName = defaultStreamLoggerName |
| 319 | if h.StreamLogs != nil { |
| 320 | if h.StreamLogs.Level != "" { |
| 321 | lvl, err := zapcore.ParseLevel(strings.ToLower(strings.TrimSpace(h.StreamLogs.Level))) |
| 322 | if err != nil { |
| 323 | return fmt.Errorf("invalid stream_logs.level %q: %w", h.StreamLogs.Level, err) |
| 324 | } |
| 325 | h.streamLogLevel = lvl |
| 326 | } |
| 327 | if name := strings.TrimSpace(h.StreamLogs.LoggerName); name != "" { |
| 328 | h.streamLogLoggerName = name |
| 329 | } |
| 330 | } |
| 331 | |
| 332 | if h.StreamDetached { |
| 333 | registerDetachedTunnelTrackers(h.tunnelTracker) |
| 334 | } |
| 335 | |
| 336 | // warn about unsafe buffering config |
| 337 | if h.RequestBuffers == -1 || h.ResponseBuffers == -1 { |
| 338 | h.logger.Warn("UNLIMITED BUFFERING: buffering is enabled without any cap on buffer size, which can result in OOM crashes") |
| 339 | } |
| 340 | |
| 341 | // start by loading modules |
| 342 | if h.TransportRaw != nil { |
| 343 | mod, err := ctx.LoadModule(h, "TransportRaw") |
| 344 | if err != nil { |
| 345 | return fmt.Errorf("loading transport: %v", err) |
| 346 | } |
| 347 | h.Transport = mod.(http.RoundTripper) |
| 348 | |
| 349 | // set default buffer sizes if applicable |
| 350 | if bt, ok := h.Transport.(BufferedTransport); ok { |
| 351 | reqBuffers, respBuffers := bt.DefaultBufferSizes() |
| 352 | if h.RequestBuffers == 0 { |
| 353 | h.RequestBuffers = reqBuffers |
| 354 | h.requestBuffersFromTransport = reqBuffers != 0 |
| 355 | } |
| 356 | if h.ResponseBuffers == 0 { |
| 357 | h.ResponseBuffers = respBuffers |
| 358 | } |
| 359 | } |
| 360 | } |
| 361 | if h.LoadBalancing != nil && h.LoadBalancing.SelectionPolicyRaw != nil { |
| 362 | mod, err := ctx.LoadModule(h.LoadBalancing, "SelectionPolicyRaw") |
| 363 | if err != nil { |
| 364 | return fmt.Errorf("loading load balancing selection policy: %s", err) |
| 365 | } |
| 366 | h.LoadBalancing.SelectionPolicy = mod.(Selector) |
| 367 | } |
| 368 | if h.CBRaw != nil { |
| 369 | mod, err := ctx.LoadModule(h, "CBRaw") |
| 370 | if err != nil { |
| 371 | return fmt.Errorf("loading circuit breaker: %s", err) |
| 372 | } |
| 373 | h.CB = mod.(CircuitBreaker) |
| 374 | } |
| 375 | if h.DynamicUpstreamsRaw != nil { |
| 376 | mod, err := ctx.LoadModule(h, "DynamicUpstreamsRaw") |
| 377 | if err != nil { |
| 378 | return fmt.Errorf("loading upstream source module: %v", err) |
| 379 | } |
| 380 | h.DynamicUpstreams = mod.(UpstreamSource) |
| 381 | } |
| 382 | |
| 383 | // parse trusted proxy CIDRs ahead of time |
| 384 | for _, str := range h.TrustedProxies { |
| 385 | if strings.Contains(str, "/") { |
| 386 | ipNet, err := netip.ParsePrefix(str) |
| 387 | if err != nil { |
| 388 | return fmt.Errorf("parsing CIDR expression: '%s': %v", str, err) |
| 389 | } |
| 390 | h.trustedProxies = append(h.trustedProxies, ipNet) |
| 391 | } else { |
| 392 | ipAddr, err := netip.ParseAddr(str) |
| 393 | if err != nil { |
| 394 | return fmt.Errorf("invalid IP address: '%s': %v", str, err) |
| 395 | } |
| 396 | ipNew := netip.PrefixFrom(ipAddr, ipAddr.BitLen()) |
| 397 | h.trustedProxies = append(h.trustedProxies, ipNew) |
| 398 | } |
| 399 | } |
| 400 | |
| 401 | // ensure any embedded headers handler module gets provisioned |
| 402 | // (see https://caddy.community/t/set-cookie-manipulation-in-reverse-proxy/7666?u=matt |
| 403 | // for what happens if we forget to provision it) |
| 404 | if h.Headers != nil { |
| 405 | err := h.Headers.Provision(ctx) |
| 406 | if err != nil { |
| 407 | return fmt.Errorf("provisioning embedded headers handler: %v", err) |
| 408 | } |
| 409 | } |
| 410 | |
| 411 | if h.Rewrite != nil { |
| 412 | err := h.Rewrite.Provision(ctx) |
| 413 | if err != nil { |
| 414 | return fmt.Errorf("provisioning rewrite: %v", err) |
| 415 | } |
| 416 | } |
| 417 | |
| 418 | // set up transport |
| 419 | if h.Transport == nil { |
| 420 | t := &HTTPTransport{} |
| 421 | err := t.Provision(ctx) |
| 422 | if err != nil { |
| 423 | return fmt.Errorf("provisioning default transport: %v", err) |
| 424 | } |
| 425 | h.Transport = t |
| 426 | } |
| 427 | |
| 428 | h.tracedTransport = newTracedTransport(h.Transport) |
| 429 | |
| 430 | // If the transport can provide header ops, cache them now so we don't |
| 431 | // have to compute them per-request. Provision the HeaderOps if present |
| 432 | // so any runtime artifacts (like precompiled regex) are prepared. |
| 433 | if tph, ok := h.Transport.(RequestHeaderOpsTransport); ok { |
| 434 | h.transportHeaderOps = tph.RequestHeaderOps() |
| 435 | if h.transportHeaderOps != nil { |
| 436 | if err := h.transportHeaderOps.Provision(ctx); err != nil { |
| 437 | return fmt.Errorf("provisioning transport header ops: %v", err) |
| 438 | } |
| 439 | } |
| 440 | } |
| 441 | |
| 442 | // set up load balancing |
| 443 | if h.LoadBalancing == nil { |
| 444 | h.LoadBalancing = new(LoadBalancing) |
| 445 | } |
| 446 | if h.LoadBalancing.SelectionPolicy == nil { |
| 447 | h.LoadBalancing.SelectionPolicy = RandomSelection{} |
| 448 | } |
| 449 | if h.LoadBalancing.TryDuration > 0 && h.LoadBalancing.TryInterval == 0 { |
| 450 | // a non-zero try_duration with a zero try_interval |
| 451 | // will always spin the CPU for try_duration if the |
| 452 | // upstream is local or low-latency; avoid that by |
| 453 | // defaulting to a sane wait period between attempts |
| 454 | h.LoadBalancing.TryInterval = caddy.Duration(250 * time.Millisecond) |
| 455 | } |
| 456 | lbMatcherSets, err := ctx.LoadModule(h.LoadBalancing, "RetryMatchRaw") |
| 457 | if err != nil { |
| 458 | return err |
| 459 | } |
| 460 | err = h.LoadBalancing.RetryMatch.FromInterface(lbMatcherSets) |
| 461 | if err != nil { |
| 462 | return err |
| 463 | } |
| 464 | |
| 465 | // set up upstreams |
| 466 | for _, u := range h.Upstreams { |
| 467 | h.provisionUpstream(u, false) |
| 468 | } |
| 469 | |
| 470 | if h.HealthChecks != nil { |
| 471 | // set defaults on passive health checks, if necessary |
| 472 | if h.HealthChecks.Passive != nil { |
| 473 | h.HealthChecks.Passive.logger = h.logger.Named("health_checker.passive") |
| 474 | if h.HealthChecks.Passive.MaxFails == 0 { |
| 475 | h.HealthChecks.Passive.MaxFails = 1 |
| 476 | } |
| 477 | } |
| 478 | |
| 479 | // if active health checks are enabled, configure them and start a worker |
| 480 | if h.HealthChecks.Active != nil { |
| 481 | err := h.HealthChecks.Active.Provision(ctx, h) |
| 482 | if err != nil { |
| 483 | return err |
| 484 | } |
| 485 | |
| 486 | if h.HealthChecks.Active.IsEnabled() { |
| 487 | go h.activeHealthChecker() |
| 488 | } |
| 489 | } |
| 490 | } |
| 491 | |
| 492 | // set up any response routes |
| 493 | for i, rh := range h.HandleResponse { |
| 494 | err := rh.Provision(ctx) |
| 495 | if err != nil { |
| 496 | return fmt.Errorf("provisioning response handler %d: %v", i, err) |
| 497 | } |
| 498 | } |
| 499 | |
| 500 | upstreamHealthyUpdater := newMetricsUpstreamsHealthyUpdater(h, ctx) |
| 501 | upstreamHealthyUpdater.init() |
| 502 | |
| 503 | return nil |
| 504 | } |
| 505 | |
| 506 | func (h Handler) streamLogsSkipHandshake() bool { |
| 507 | return h.StreamLogs != nil && h.StreamLogs.SkipHandshake |
| 508 | } |
| 509 | |
| 510 | func (h Handler) streamLoggerForRequest(req *http.Request) *zap.Logger { |
| 511 | name := strings.TrimSpace(h.streamLogLoggerName) |
| 512 | if name == "" { |
| 513 | name = defaultStreamLoggerName |
| 514 | } |
| 515 | |
| 516 | if name == streamLoggerNameUseAccess { |
| 517 | logger := caddy.Log().Named(defaultAccessLoggerBase) |
| 518 | names := caddyhttp.GetVar(req.Context(), caddyhttp.AccessLoggerNameVarKey) |
| 519 | namesSlice, ok := names.([]any) |
| 520 | if !ok { |
| 521 | return logger |
| 522 | } |
| 523 | for _, v := range namesSlice { |
| 524 | name, ok := v.(string) |
| 525 | if !ok { |
| 526 | continue |
| 527 | } |
| 528 | if name == "" { |
| 529 | return logger |
| 530 | } |
| 531 | return logger.Named(name) |
| 532 | } |
| 533 | return logger |
| 534 | } |
| 535 | |
| 536 | return caddy.Log().Named(name) |
| 537 | } |
| 538 | |
| 539 | var ( |
| 540 | detachedTunnelTrackers = make(map[*tunnelTracker]struct{}) |
| 541 | detachedTunnelTrackersMu sync.Mutex |
| 542 | ) |
| 543 | |
| 544 | func registerDetachedTunnelTrackers(ts *tunnelTracker) { |
| 545 | detachedTunnelTrackersMu.Lock() |
| 546 | defer detachedTunnelTrackersMu.Unlock() |
| 547 | detachedTunnelTrackers[ts] = struct{}{} |
| 548 | } |
| 549 | |
| 550 | func notifyDetachedTunnelTrackersOfUpstreamRemoval(upstream string, self *tunnelTracker) error { |
| 551 | detachedTunnelTrackersMu.Lock() |
| 552 | trackers := make([]*tunnelTracker, 0, len(detachedTunnelTrackers)) |
| 553 | for tunnel := range detachedTunnelTrackers { |
| 554 | trackers = append(trackers, tunnel) |
| 555 | } |
| 556 | detachedTunnelTrackersMu.Unlock() |
| 557 | |
| 558 | // Connection deletion unregisters empty trackers. Do not hold the |
| 559 | // registry lock while acquiring tracker locks or closing connections. |
| 560 | // One deadline for every tracker; see closeConnectionsLocked. |
| 561 | deadline := time.Now().Add(closeControlWriteTimeout) |
| 562 | var err error |
| 563 | for _, tunnel := range trackers { |
| 564 | if closeErr := tunnel.closeConnectionsForUpstream(upstream, deadline); closeErr != nil && tunnel == self && err == nil { |
| 565 | err = closeErr |
| 566 | } |
| 567 | } |
| 568 | return err |
| 569 | } |
| 570 | |
| 571 | func unregisterDetachedTunnelTrackers(ts *tunnelTracker) { |
| 572 | detachedTunnelTrackersMu.Lock() |
| 573 | defer detachedTunnelTrackersMu.Unlock() |
| 574 | delete(detachedTunnelTrackers, ts) |
| 575 | } |
| 576 | |
| 577 | // Cleanup cleans up the resources made by h. |
| 578 | func (h *Handler) Cleanup() error { |
| 579 | // even if StreamDetached is true, extended connect websockets may still be running |
| 580 | err := h.tunnelTracker.cleanupAttachedConnections() |
| 581 | for _, upstream := range h.Upstreams { |
| 582 | // hosts.Delete returns deleted=true when the ref count reaches zero, |
| 583 | // meaning no other active config references this upstream. In that |
| 584 | // case close any tunnels proxying to it; otherwise let them survive |
| 585 | // to their natural end since the upstream is still in use. |
| 586 | deleted, _ := hosts.Delete(upstream.String()) |
| 587 | if deleted { |
| 588 | if closeErr := notifyDetachedTunnelTrackersOfUpstreamRemoval(upstream.String(), h.tunnelTracker); closeErr != nil && err == nil { |
| 589 | err = closeErr |
| 590 | } |
| 591 | } |
| 592 | } |
| 593 | return err |
| 594 | } |
| 595 | |
| 596 | // bodyNopCloserIfNotRead wraps a request body to prevent closing if not read, i.e., when |
| 597 | // dialing to upstream fails. |
| 598 | // It will close the body as normal if the body is read. |
| 599 | type bodyNopCloserIfNotRead struct { |
| 600 | io.ReadCloser |
| 601 | read int // tracks the number of bytes read, -1 when first Read returns 0, io.EOF |
| 602 | } |
| 603 | |
| 604 | func (b *bodyNopCloserIfNotRead) Read(p []byte) (int, error) { |
| 605 | if b.read == -1 { |
| 606 | return 0, io.EOF |
| 607 | } |
| 608 | n, err := b.ReadCloser.Read(p) |
| 609 | // first Read returns 0, io.EOF |
| 610 | if b.read == 0 && n == 0 && err == io.EOF { |
| 611 | b.read = -1 |
| 612 | } else { |
| 613 | b.read += n |
| 614 | } |
| 615 | return n, err |
| 616 | } |
| 617 | |
| 618 | func (b *bodyNopCloserIfNotRead) Close() error { |
| 619 | // don't close the body |
| 620 | if b.read == 0 { |
| 621 | return nil |
| 622 | } |
| 623 | // close as usual, when -1, any read will return EOF as the original read will do |
| 624 | // in other cases, the read will fail as body is closed because we do not want partial bodies to be sent to the upstream |
| 625 | // users can buffer the entire request body to allow the request to be resent |
| 626 | return b.ReadCloser.Close() |
| 627 | } |
| 628 | |
| 629 | func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error { |
| 630 | repl := r.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer) |
| 631 | |
| 632 | // prepare the request for proxying; this is needed only once |
| 633 | clonedReq, err := h.prepareRequest(r, repl) |
| 634 | if err != nil { |
| 635 | if errors.Is(err, errIncrementalRefused) { |
| 636 | return h.refuseIncremental(w, nil) |
| 637 | } |
| 638 | return caddyhttp.Error(http.StatusInternalServerError, |
| 639 | fmt.Errorf("preparing request for upstream round-trip: %v", err)) |
| 640 | } |
| 641 | |
| 642 | // websocket over http2 or http3 if extended connect is enabled, assuming backend doesn't support this, the request will be modified to http1.1 upgrade |
| 643 | // Both use the same upgrade mechanism: server advertizes extended connect support, and client sends the pseudo header :protocol in a CONNECT request |
| 644 | // The quic-go http3 implementation also puts :protocol in r.Proto for CONNECT requests (quic-go/http3/headers.go@70-72,185,203) |
| 645 | // TODO: once we can reliably detect backend support this, it can be removed for those backends |
| 646 | if (r.ProtoMajor == 2 && r.Method == http.MethodConnect && r.Header.Get(":protocol") == "websocket") || |
| 647 | (r.ProtoMajor == 3 && r.Method == http.MethodConnect && r.Proto == "websocket") { |
| 648 | clonedReq.Header.Del(":protocol") |
| 649 | // keep the body for later use. http1.1 upgrade uses http.NoBody |
| 650 | caddyhttp.SetVar(clonedReq.Context(), "extended_connect_websocket_body", clonedReq.Body) |
| 651 | clonedReq.Body = http.NoBody |
| 652 | clonedReq.Method = http.MethodGet |
| 653 | clonedReq.Header.Set("Upgrade", "websocket") |
| 654 | clonedReq.Header.Set("Connection", "Upgrade") |
| 655 | key := make([]byte, 16) |
| 656 | _, randErr := rand.Read(key) |
| 657 | if randErr != nil { |
| 658 | return randErr |
| 659 | } |
| 660 | clonedReq.Header.Set("Sec-WebSocket-Key", base64.StdEncoding.EncodeToString(key)) |
| 661 | } |
| 662 | |
| 663 | // we will need the original headers and Host value if |
| 664 | // header operations are configured; this is so that each |
| 665 | // retry can apply the modifications, because placeholders |
| 666 | // may be used which depend on the selected upstream for |
| 667 | // their values |
| 668 | reqHost := clonedReq.Host |
| 669 | reqHeader := clonedReq.Header |
| 670 | requestWasIncremental := caddyhttp.IsIncremental(reqHeader) |
| 671 | |
| 672 | // If the request contained a body, wrap it in io.NopCloser |
| 673 | // to prevent Go's transport from closing it on dial errors. |
| 674 | // cloneRequest does a shallow copy, so clonedReq.Body and |
| 675 | // r.Body share the same io.ReadCloser — a dial-failure Close() |
| 676 | // would kill the original body for all subsequent retry |
| 677 | // attempts or subsequent handlers. The real body is closed by |
| 678 | // the HTTP server when the handler returns. |
| 679 | // |
| 680 | // If the body was already fully buffered (via request_buffers), |
| 681 | // we also extract the buffer so the retry loop can replay it |
| 682 | // from the beginning on each attempt. (see #6259, #7546, #7713) |
| 683 | var bufferedReqBody *bytes.Buffer |
| 684 | if clonedReq.Body != nil { |
| 685 | if reqBodyBuf, ok := clonedReq.Body.(bodyReadCloser); ok && reqBodyBuf.body == nil && reqBodyBuf.buf != nil { |
| 686 | bufferedReqBody = reqBodyBuf.buf |
| 687 | reqBodyBuf.buf = nil |
| 688 | clonedReq.Body = io.NopCloser(bytes.NewReader(bufferedReqBody.Bytes())) |
| 689 | defer func() { |
| 690 | bufferedReqBody.Reset() |
| 691 | bufPool.Put(bufferedReqBody) |
| 692 | }() |
| 693 | } else { |
| 694 | clonedReq.Body = &bodyNopCloserIfNotRead{ReadCloser: clonedReq.Body} |
| 695 | } |
| 696 | } |
| 697 | |
| 698 | start := time.Now() |
| 699 | defer func() { |
| 700 | // total proxying duration, including time spent on LB and retries |
| 701 | repl.Set("http.reverse_proxy.duration", time.Since(start)) |
| 702 | repl.Set("http.reverse_proxy.duration_ms", time.Since(start).Seconds()*1e3) // multiply seconds to preserve decimal (see #4666) |
| 703 | }() |
| 704 | |
| 705 | // in the proxy loop, each iteration is an attempt to proxy the request, |
| 706 | // and because we may retry some number of times, carry over the error |
| 707 | // from previous tries because of the nuances of load balancing & retries |
| 708 | var proxyErr error |
| 709 | var retries int |
| 710 | for { |
| 711 | // if the request body was buffered (and only the entire body, hence no body |
| 712 | // set to read from after the buffer), make reading from the body idempotent |
| 713 | // and reusable, so if a backend partially or fully reads the body but then |
| 714 | // produces an error, the request can be repeated to the next backend with |
| 715 | // the full body (retries should only happen for idempotent requests) (see #6259) |
| 716 | if bufferedReqBody != nil { |
| 717 | clonedReq.Body = io.NopCloser(bytes.NewReader(bufferedReqBody.Bytes())) |
| 718 | } |
| 719 | |
| 720 | var done bool |
| 721 | done, proxyErr = h.proxyLoopIteration(clonedReq, r, w, proxyErr, start, retries, repl, reqHeader, reqHost, requestWasIncremental, next) |
| 722 | if done { |
| 723 | break |
| 724 | } |
| 725 | if h.VerboseLogs { |
| 726 | var lbWait time.Duration |
| 727 | if h.LoadBalancing != nil { |
| 728 | lbWait = time.Duration(h.LoadBalancing.TryInterval) |
| 729 | } |
| 730 | if c := h.logger.Check(zapcore.DebugLevel, "retrying"); c != nil { |
| 731 | c.Write(zap.Error(proxyErr), zap.Duration("after", lbWait)) |
| 732 | } |
| 733 | } |
| 734 | retries++ |
| 735 | } |
| 736 | |
| 737 | // number of retries actually performed |
| 738 | repl.Set("http.reverse_proxy.retries", retries) |
| 739 | |
| 740 | if proxyErr != nil { |
| 741 | return statusError(proxyErr) |
| 742 | } |
| 743 | |
| 744 | return nil |
| 745 | } |
| 746 | |
| 747 | // proxyLoopIteration implements an iteration of the proxy loop. Despite the enormous amount of local state |
| 748 | // that has to be passed in, we brought this into its own method so that we could run defer more easily. |
| 749 | // It returns true when the loop is done and should break; false otherwise. The error value returned should |
| 750 | // be assigned to the proxyErr value for the next iteration of the loop (or the error handled after break). |
| 751 | func (h *Handler) proxyLoopIteration(r *http.Request, origReq *http.Request, w http.ResponseWriter, proxyErr error, start time.Time, retries int, |
| 752 | repl *caddy.Replacer, reqHeader http.Header, reqHost string, requestWasIncremental bool, next caddyhttp.Handler, |
| 753 | ) (bool, error) { |
| 754 | // get the updated list of upstreams |
| 755 | upstreams := h.Upstreams |
| 756 | if h.DynamicUpstreams != nil { |
| 757 | if retries > 0 { |
| 758 | // after a failure (and thus during a retry), give dynamic upstream modules an opportunity |
| 759 | // to purge their relevant cache entries so we don't keep retrying bad upstreams |
| 760 | if cachingDynamicUpstreams, ok := h.DynamicUpstreams.(CachingUpstreamSource); ok { |
| 761 | if err := cachingDynamicUpstreams.ResetCache(r); err != nil { |
| 762 | if c := h.logger.Check(zapcore.ErrorLevel, "failed clearing dynamic upstream source's cache"); c != nil { |
| 763 | c.Write(zap.Error(err)) |
| 764 | } |
| 765 | } |
| 766 | } |
| 767 | } |
| 768 | dUpstreams, err := h.DynamicUpstreams.GetUpstreams(r) |
| 769 | if err != nil { |
| 770 | if c := h.logger.Check(zapcore.ErrorLevel, "failed getting dynamic upstreams; falling back to static upstreams"); c != nil { |
| 771 | c.Write(zap.Error(err)) |
| 772 | } |
| 773 | } else { |
| 774 | upstreams = dUpstreams |
| 775 | for _, dUp := range dUpstreams { |
| 776 | h.provisionUpstream(dUp, true) |
| 777 | } |
| 778 | if c := h.logger.Check(zapcore.DebugLevel, "provisioned dynamic upstreams"); c != nil { |
| 779 | c.Write(zap.Int("count", len(dUpstreams))) |
| 780 | } |
| 781 | } |
| 782 | } |
| 783 | |
| 784 | // choose an available upstream |
| 785 | upstream := h.LoadBalancing.SelectionPolicy.Select(upstreams, r, w) |
| 786 | if upstream == nil { |
| 787 | if proxyErr == nil { |
| 788 | proxyErr = caddyhttp.Error(http.StatusServiceUnavailable, errNoUpstream) |
| 789 | } |
| 790 | if !h.LoadBalancing.tryAgain(h.ctx, start, retries, proxyErr, r, h.logger) { |
| 791 | return true, proxyErr |
| 792 | } |
| 793 | return false, proxyErr |
| 794 | } |
| 795 | |
| 796 | // the dial address may vary per-request if placeholders are |
| 797 | // used, so perform those replacements here; the resulting |
| 798 | // DialInfo struct should have valid network address syntax |
| 799 | dialInfo, err := upstream.fillDialInfo(repl) |
| 800 | if err != nil { |
| 801 | return true, fmt.Errorf("making dial info: %v", err) |
| 802 | } |
| 803 | |
| 804 | if c := h.logger.Check(zapcore.DebugLevel, "selected upstream"); c != nil { |
| 805 | c.Write( |
| 806 | zap.String("dial", dialInfo.Address), |
| 807 | zap.Int("total_upstreams", len(upstreams)), |
| 808 | ) |
| 809 | } |
| 810 | |
| 811 | // set placeholders with information about this upstream |
| 812 | repl.Set("http.reverse_proxy.upstream.address", dialInfo.String()) |
| 813 | repl.Set("http.reverse_proxy.upstream.hostport", dialInfo.Address) |
| 814 | repl.Set("http.reverse_proxy.upstream.host", dialInfo.Host) |
| 815 | repl.Set("http.reverse_proxy.upstream.port", dialInfo.Port) |
| 816 | repl.Set("http.reverse_proxy.upstream.requests", upstream.Host.NumRequests()) |
| 817 | repl.Set("http.reverse_proxy.upstream.max_requests", upstream.MaxRequests) |
| 818 | repl.Set("http.reverse_proxy.upstream.fails", upstream.Host.Fails()) |
| 819 | |
| 820 | // mutate request headers according to this upstream; |
| 821 | // because we're in a retry loop, we have to copy headers |
| 822 | // (and the r.Host value) from the original so that each |
| 823 | // retry is identical to the first. If either transport or |
| 824 | // user ops exist, apply them in order (transport first, |
| 825 | // then user, so user's config wins). |
| 826 | var userOps *headers.HeaderOps |
| 827 | if h.Headers != nil { |
| 828 | userOps = h.Headers.Request |
| 829 | } |
| 830 | transportOps := h.transportHeaderOps |
| 831 | if transportOps != nil || userOps != nil { |
| 832 | r.Header = make(http.Header) |
| 833 | copyHeader(r.Header, reqHeader) |
| 834 | r.Host = reqHost |
| 835 | if transportOps != nil { |
| 836 | transportOps.ApplyToRequest(r) |
| 837 | } |
| 838 | if userOps != nil { |
| 839 | userOps.ApplyToRequest(r) |
| 840 | } |
| 841 | } |
| 842 | if !requestWasIncremental && requestHasContent(r) && caddyhttp.IsIncremental(r.Header) && |
| 843 | (h.RequestBuffers != 0 || r.ContentLength < 0 && h.transportRequiresContentLength()) { |
| 844 | return true, h.refuseIncremental(w, nil) |
| 845 | } |
| 846 | normalizeIncrementalRequest(r) |
| 847 | |
| 848 | // normalize websocket headers for compatibility with older servers |
| 849 | if upgradeType(r.Header) != "" { |
| 850 | normalizeWebsocketHeaders(r.Header) |
| 851 | } |
| 852 | |
| 853 | // proxy the request to that upstream |
| 854 | proxyErr = h.reverseProxy(w, r, origReq, repl, dialInfo, next) |
| 855 | if proxyErr == nil { |
| 856 | return true, nil |
| 857 | } |
| 858 | if errors.Is(proxyErr, context.Canceled) { |
| 859 | // context.Canceled happens when the downstream client cancels the |
| 860 | // request, which is not our failure; don't retry or ding the upstream. |
| 861 | // Record a 499 (client closed request) so the access log reflects the |
| 862 | // disconnect instead of a misleading 0 status (see #7396). |
| 863 | w.WriteHeader(499) |
| 864 | return true, nil |
| 865 | } |
| 866 | |
| 867 | // if the handler has already committed a client-visible response |
| 868 | // (e.g. a successful roundtrip whose handle_response route errored, |
| 869 | // or a WebTransport upgrade that flushed 200 OK and hijacked the |
| 870 | // stream), don't retry against another upstream and don't ding the |
| 871 | // upstream's health status |
| 872 | if term, ok := proxyErr.(terminalError); ok { |
| 873 | return true, term.error |
| 874 | } |
| 875 | |
| 876 | // remember this failure (if enabled); response-based retries |
| 877 | // are not counted as failures since the upstream did respond |
| 878 | // successfully - only the response content triggered a retry |
| 879 | if _, isRetryableResponse := proxyErr.(retryableResponseError); !isRetryableResponse { |
| 880 | h.countFailure(upstream) |
| 881 | } |
| 882 | |
| 883 | // if we've tried long enough, break |
| 884 | if !h.LoadBalancing.tryAgain(h.ctx, start, retries, proxyErr, r, h.logger) { |
| 885 | return true, proxyErr |
| 886 | } |
| 887 | |
| 888 | return false, proxyErr |
| 889 | } |
| 890 | |
| 891 | // Mapping of the canonical form of the headers, to the RFC 6455 form, |
| 892 | // i.e. `WebSocket` with uppercase 'S'. |
| 893 | var websocketHeaderMapping = map[string]string{ |
| 894 | "Sec-Websocket-Accept": "Sec-WebSocket-Accept", |
| 895 | "Sec-Websocket-Extensions": "Sec-WebSocket-Extensions", |
| 896 | "Sec-Websocket-Key": "Sec-WebSocket-Key", |
| 897 | "Sec-Websocket-Protocol": "Sec-WebSocket-Protocol", |
| 898 | "Sec-Websocket-Version": "Sec-WebSocket-Version", |
| 899 | } |
| 900 | |
| 901 | // normalizeWebsocketHeaders ensures we use the standard casing as per |
| 902 | // RFC 6455, i.e. `WebSocket` with uppercase 'S'. Most servers don't |
| 903 | // care about this difference (read headers case insensitively), but |
| 904 | // some do, so this maximizes compatibility with upstreams. |
| 905 | // See https://github.com/caddyserver/caddy/pull/6621 |
| 906 | func normalizeWebsocketHeaders(header http.Header) { |
| 907 | for k, rk := range websocketHeaderMapping { |
| 908 | if v, ok := header[k]; ok { |
| 909 | delete(header, k) |
| 910 | header[rk] = v |
| 911 | } |
| 912 | } |
| 913 | } |
| 914 | |
| 915 | // prepareRequest clones req so that it can be safely modified without |
| 916 | // changing the original request or introducing data races. It then |
| 917 | // modifies it so that it is ready to be proxied, except for directing |
| 918 | // to a specific upstream. This method adjusts headers and other relevant |
| 919 | // properties of the cloned request and should be done just once (before |
| 920 | // proxying) regardless of proxy retries. This assumes that no mutations |
| 921 | // of the cloned request are performed by h during or after proxying. |
| 922 | func (h Handler) prepareRequest(req *http.Request, repl *caddy.Replacer) (*http.Request, error) { |
| 923 | origReq := req |
| 924 | req = cloneRequest(req) |
| 925 | |
| 926 | // if enabled, perform rewrites on the cloned request; if |
| 927 | // the method is GET or HEAD, prevent the request body |
| 928 | // from being copied to the upstream |
| 929 | if h.Rewrite != nil { |
| 930 | changed := h.Rewrite.Rewrite(req, repl) |
| 931 | if changed && (h.Rewrite.Method == "GET" || h.Rewrite.Method == "HEAD") { |
| 932 | req.ContentLength = 0 |
| 933 | req.Body = nil |
| 934 | } |
| 935 | } |
| 936 | |
| 937 | if req.Body != nil { |
| 938 | // net/http fills in the incoming trailers only when Body.Read reaches |
| 939 | // EOF. Keep an independent map, but update it in that same Read before |
| 940 | // the transport writes the trailers. Install this before buffering, |
| 941 | // which may itself consume the body to EOF before the round trip. |
| 942 | if req.Trailer == nil { |
| 943 | req.Trailer = make(http.Header) |
| 944 | } |
| 945 | req.Body = &requestBodyWithTrailers{ReadCloser: req.Body, original: origReq, trailer: req.Trailer} |
| 946 | } |
| 947 | |
| 948 | // Fully buffering the request is incompatible with incremental forwarding. |
| 949 | // A negative length is treated as potential content because determining |
| 950 | // whether it is empty would itself require waiting for the stream to end. |
| 951 | if h.incrementalRequestConflicts(req) { |
| 952 | return nil, errIncrementalRefused |
| 953 | } |
| 954 | normalizeIncrementalRequest(req) |
| 955 | |
| 956 | // if enabled, buffer client request; this should only be |
| 957 | // enabled if the upstream requires it and does not work |
| 958 | // with "slow clients" (gunicorn, etc.) - this obviously |
| 959 | // has a perf overhead and makes the proxy at risk of |
| 960 | // exhausting memory and more susceptible to slowloris |
| 961 | // attacks, so it is strongly recommended to only use this |
| 962 | // feature if absolutely required, if read timeouts are |
| 963 | // set, and if body size is limited |
| 964 | if h.RequestBuffers != 0 && req.Body != nil && !caddyhttp.IsIncremental(req.Header) { |
| 965 | var readBytes int64 |
| 966 | req.Body, readBytes = h.bufferedBody(req.Body, h.RequestBuffers) |
| 967 | // set Content-Length when body is fully buffered |
| 968 | if b, ok := req.Body.(bodyReadCloser); ok && b.body == nil { |
| 969 | req.ContentLength = readBytes |
| 970 | req.Header["Content-Length"] = []string{strconv.FormatInt(req.ContentLength, 10)} |
| 971 | } |
| 972 | } |
| 973 | |
| 974 | // HTTP/1 upstreams require chunked framing to carry trailers, including |
| 975 | // when buffering has made the body length known (or the body is empty). |
| 976 | // Length-required transports such as FastCGI need the buffered length and |
| 977 | // do not carry HTTP trailers. |
| 978 | if len(req.Trailer) > 0 && req.Body != nil && !h.transportRequiresContentLength() { |
| 979 | req.ContentLength = -1 |
| 980 | req.Header.Del("Content-Length") |
| 981 | } |
| 982 | |
| 983 | if req.ContentLength == 0 { |
| 984 | req.Body = nil // Issue golang/go#16036: nil Body for http.Transport retries |
| 985 | } |
| 986 | |
| 987 | req.Close = false |
| 988 | |
| 989 | // if User-Agent is not set by client, then explicitly |
| 990 | // disable it so it's not set to default value by std lib |
| 991 | if _, ok := req.Header["User-Agent"]; !ok { |
| 992 | req.Header["User-Agent"] = []string{""} |
| 993 | } |
| 994 | |
| 995 | // Indicate if request has been conveyed in early data. |
| 996 | // RFC 8470: "An intermediary that forwards a request prior to the |
| 997 | // completion of the TLS handshake with its client MUST send it with |
| 998 | // the Early-Data header field set to “1” (i.e., it adds it if not |
| 999 | // present in the request). An intermediary MUST use the Early-Data |
| 1000 | // header field if the request might have been subject to a replay and |
| 1001 | // might already have been forwarded by it or another instance |
| 1002 | // (see Section 6.2)." |
| 1003 | if req.TLS != nil && !req.TLS.HandshakeComplete { |
| 1004 | req.Header["Early-Data"] = []string{"1"} |
| 1005 | } |
| 1006 | |
| 1007 | reqUpgradeType := upgradeType(req.Header) |
| 1008 | removeConnectionHeaders(req.Header) |
| 1009 | |
| 1010 | // Remove hop-by-hop headers to the backend. Especially |
| 1011 | // important is "Connection" because we want a persistent |
| 1012 | // connection, regardless of what the client sent to us. |
| 1013 | // Issue golang/go#46313: don't skip if field is empty. |
| 1014 | for _, h := range hopHeaders { |
| 1015 | // Issue golang/go#21096: tell backend applications that care about trailer support |
| 1016 | // that we support trailers. (We do, but we don't go out of our way to |
| 1017 | // advertise that unless the incoming client request thought it was worth |
| 1018 | // mentioning.) |
| 1019 | if h == "Te" && httpguts.HeaderValuesContainsToken(req.Header["Te"], "trailers") { |
| 1020 | req.Header["Te"] = []string{"trailers"} |
| 1021 | continue |
| 1022 | } |
| 1023 | // hopHeaders are already canonical, so skip the normalization Del does |
| 1024 | delete(req.Header, h) |
| 1025 | } |
| 1026 | |
| 1027 | // After stripping all the hop-by-hop connection headers above, add back any |
| 1028 | // necessary for protocol upgrades, such as for websockets. |
| 1029 | if reqUpgradeType != "" { |
| 1030 | req.Header["Connection"] = []string{"Upgrade"} |
| 1031 | req.Header["Upgrade"] = []string{reqUpgradeType} |
| 1032 | } |
| 1033 | |
| 1034 | // Set up the PROXY protocol info |
| 1035 | address := caddyhttp.GetVar(req.Context(), caddyhttp.ClientIPVarKey).(string) |
| 1036 | addrPort, err := netip.ParseAddrPort(address) |
| 1037 | if err != nil { |
| 1038 | // OK; probably didn't have a port |
| 1039 | addr, err := netip.ParseAddr(address) |
| 1040 | if err != nil { |
| 1041 | // Doesn't seem like a valid ip address at all |
| 1042 | } else { |
| 1043 | // Ok, only the port was missing |
| 1044 | addrPort = netip.AddrPortFrom(addr, 0) |
| 1045 | } |
| 1046 | } |
| 1047 | proxyProtocolInfo := ProxyProtocolInfo{AddrPort: addrPort} |
| 1048 | caddyhttp.SetVar(req.Context(), proxyProtocolInfoVarKey, proxyProtocolInfo) |
| 1049 | |
| 1050 | // some of the outbound requests require h1 (e.g. websocket) |
| 1051 | // https://github.com/golang/go/blob/4837fbe4145cd47b43eed66fee9eed9c2b988316/src/net/http/request.go#L1579 |
| 1052 | if isWebsocket(req) { |
| 1053 | caddyhttp.SetVar(req.Context(), tlsH1OnlyVarKey, true) |
| 1054 | } |
| 1055 | |
| 1056 | // Add the supported X-Forwarded-* headers |
| 1057 | err = h.addForwardedHeaders(req) |
| 1058 | if err != nil { |
| 1059 | return nil, err |
| 1060 | } |
| 1061 | |
| 1062 | // Via header(s) |
| 1063 | req.Header["Via"] = append(req.Header["Via"], |
| 1064 | strconv.Itoa(req.ProtoMajor)+"."+strconv.Itoa(req.ProtoMinor)+" Caddy") |
| 1065 | |
| 1066 | return req, nil |
| 1067 | } |
| 1068 | |
| 1069 | // addForwardedHeaders adds the de-facto standard X-Forwarded-* |
| 1070 | // headers to the request before it is sent upstream. |
| 1071 | // |
| 1072 | // These headers are security sensitive, so care is taken to only |
| 1073 | // use existing values for these headers from the incoming request |
| 1074 | // if the client IP is trusted (i.e. coming from a trusted proxy |
| 1075 | // sitting in front of this server). If the request didn't have |
| 1076 | // the headers at all, then they will be added with the values |
| 1077 | // that we can glean from the request. |
| 1078 | func (h Handler) addForwardedHeaders(req *http.Request) error { |
| 1079 | // Check if the client is a trusted proxy |
| 1080 | trusted := caddyhttp.GetVar(req.Context(), caddyhttp.TrustedProxyVarKey).(bool) |
| 1081 | |
| 1082 | var clientIP string |
| 1083 | |
| 1084 | if req.RemoteAddr == "@" { |
| 1085 | // For Unix socket connections, RemoteAddr is "@" which cannot |
| 1086 | // be parsed as host:port. If untrusted, strip forwarded headers |
| 1087 | // for security. If trusted, there is no peer IP to append to |
| 1088 | // X-Forwarded-For, so clientIP stays empty. |
| 1089 | if !trusted { |
| 1090 | delete(req.Header, "X-Forwarded-For") |
| 1091 | delete(req.Header, "X-Forwarded-Proto") |
| 1092 | delete(req.Header, "X-Forwarded-Host") |
| 1093 | return nil |
| 1094 | } |
| 1095 | } else { |
| 1096 | // Parse the remote IP, ignore the error as non-fatal, |
| 1097 | // but the remote IP is required to continue, so we |
| 1098 | // just return early. This should probably never happen |
| 1099 | // though, unless some other module manipulated the request's |
| 1100 | // remote address and used an invalid value. |
| 1101 | var err error |
| 1102 | clientIP, _, err = net.SplitHostPort(req.RemoteAddr) |
| 1103 | if err != nil { |
| 1104 | // Remove the `X-Forwarded-*` headers to avoid upstreams |
| 1105 | // potentially trusting a header that came from the client |
| 1106 | delete(req.Header, "X-Forwarded-For") |
| 1107 | delete(req.Header, "X-Forwarded-Proto") |
| 1108 | delete(req.Header, "X-Forwarded-Host") |
| 1109 | return nil |
| 1110 | } |
| 1111 | |
| 1112 | // Client IP may contain a zone if IPv6, so we need |
| 1113 | // to pull that out before parsing the IP |
| 1114 | clientIP, _, _ = strings.Cut(clientIP, "%") |
| 1115 | ipAddr, err := netip.ParseAddr(clientIP) |
| 1116 | |
| 1117 | // If ParseAddr fails (e.g. non-IP network like SCION), we cannot check |
| 1118 | // if it is a trusted proxy by IP range. In this case, we ignore the |
| 1119 | // error and treat the connection as untrusted (or retain existing status). |
| 1120 | if err == nil { |
| 1121 | for _, ipRange := range h.trustedProxies { |
| 1122 | if ipRange.Contains(ipAddr) { |
| 1123 | trusted = true |
| 1124 | break |
| 1125 | } |
| 1126 | } |
| 1127 | } |
| 1128 | } |
| 1129 | |
| 1130 | // If we aren't the first proxy, and the proxy is trusted, |
| 1131 | // retain prior X-Forwarded-For information as a comma+space |
| 1132 | // separated list and fold multiple headers into one. |
| 1133 | prior, ok, omit := allHeaderValues(req.Header, "X-Forwarded-For") |
| 1134 | if !omit { |
| 1135 | if trusted && ok && prior != "" { |
| 1136 | if clientIP != "" { |
| 1137 | req.Header["X-Forwarded-For"] = []string{prior + ", " + clientIP} |
| 1138 | } else { |
| 1139 | req.Header["X-Forwarded-For"] = []string{prior} |
| 1140 | } |
| 1141 | } else if clientIP != "" { |
| 1142 | req.Header["X-Forwarded-For"] = []string{clientIP} |
| 1143 | } |
| 1144 | } |
| 1145 | |
| 1146 | // Set X-Forwarded-Proto; many backend apps expect this, |
| 1147 | // so that they can properly craft URLs with the right |
| 1148 | // scheme to match the original request |
| 1149 | proto := "https" |
| 1150 | if req.TLS == nil { |
| 1151 | proto = "http" |
| 1152 | } |
| 1153 | prior, ok, omit = lastHeaderValue(req.Header, "X-Forwarded-Proto") |
| 1154 | if trusted && ok && prior != "" { |
| 1155 | proto = prior |
| 1156 | } |
| 1157 | if !omit { |
| 1158 | req.Header["X-Forwarded-Proto"] = []string{proto} |
| 1159 | } |
| 1160 | |
| 1161 | // Set X-Forwarded-Host; often this is redundant because |
| 1162 | // we pass through the request Host as-is, but in situations |
| 1163 | // where we proxy over HTTPS, the user may need to override |
| 1164 | // Host themselves, so it's helpful to send the original too. |
| 1165 | host := req.Host |
| 1166 | prior, ok, omit = lastHeaderValue(req.Header, "X-Forwarded-Host") |
| 1167 | if trusted && ok && prior != "" { |
| 1168 | host = prior |
| 1169 | } |
| 1170 | if !omit { |
| 1171 | req.Header["X-Forwarded-Host"] = []string{host} |
| 1172 | } |
| 1173 | |
| 1174 | return nil |
| 1175 | } |
| 1176 | |
| 1177 | // reverseProxy performs a round-trip to the given backend and processes the response with the client. |
| 1178 | // (This method is mostly the beginning of what was borrowed from the net/http/httputil package in the |
| 1179 | // Go standard library which was used as the foundation.) |
| 1180 | func (h *Handler) reverseProxy(rw http.ResponseWriter, req *http.Request, origReq *http.Request, repl *caddy.Replacer, di DialInfo, next caddyhttp.Handler) error { |
| 1181 | _ = di.Upstream.Host.countRequest(1) |
| 1182 | |
| 1183 | // Increment the in-flight request count |
| 1184 | incInFlightRequest(di.Address) |
| 1185 | |
| 1186 | //nolint:errcheck |
| 1187 | defer func() { |
| 1188 | di.Upstream.Host.countRequest(-1) |
| 1189 | // Decrement the in-flight request count |
| 1190 | decInFlightRequest(di.Address) |
| 1191 | }() |
| 1192 | |
| 1193 | // point the request to this upstream |
| 1194 | h.directRequest(req, di) |
| 1195 | |
| 1196 | server := req.Context().Value(caddyhttp.ServerCtxKey).(*caddyhttp.Server) |
| 1197 | shouldLogCredentials := server.Logs != nil && server.Logs.ShouldLogCredentials |
| 1198 | |
| 1199 | // WebTransport: Extended CONNECT :protocol=webtransport can't flow |
| 1200 | // through the normal HTTP round-trip — the session hosts many QUIC |
| 1201 | // streams and datagrams that need bidirectional pumping. Swap |
| 1202 | // RoundTrip for a small hijack helper. Upstream dial failures |
| 1203 | // surface as DialError so the loop can retry across upstreams; |
| 1204 | // pre-upgrade misconfig and post-upgrade failures return |
| 1205 | // terminalError because the response is already committed to the |
| 1206 | // client or no upstream can fix the condition. |
| 1207 | if isWebTransportExtendedConnect(origReq) { |
| 1208 | return h.webTransportHijack(rw, req, origReq, repl, di, server) |
| 1209 | } |
| 1210 | |
| 1211 | // Forward 1xx status codes, backported from https://github.com/golang/go/pull/53164 |
| 1212 | var ( |
| 1213 | roundTripMutex sync.Mutex |
| 1214 | roundTripDone bool |
| 1215 | ) |
| 1216 | trace := &httptrace.ClientTrace{ |
| 1217 | Got1xxResponse: func(code int, header textproto.MIMEHeader) error { |
| 1218 | roundTripMutex.Lock() |
| 1219 | defer roundTripMutex.Unlock() |
| 1220 | if roundTripDone { |
| 1221 | // If RoundTrip has returned, don't try to further modify |
| 1222 | // the ResponseWriter's header map. |
| 1223 | return nil |
| 1224 | } |
| 1225 | h := rw.Header() |
| 1226 | ownHeaders := h.Clone() |
| 1227 | upstreamHeaders := http.Header(header).Clone() |
| 1228 | stripHopByHopHeaders(upstreamHeaders) |
| 1229 | copyHeader(h, upstreamHeaders) |
| 1230 | rw.WriteHeader(code) |
| 1231 | |
| 1232 | // Clear headers coming from the backend, keeping our own |
| 1233 | // (it's not automatically done by ResponseWriter.WriteHeader() for 1xx responses) |
| 1234 | clear(h) |
| 1235 | maps.Copy(h, ownHeaders) |
| 1236 | |
| 1237 | return nil |
| 1238 | }, |
| 1239 | } |
| 1240 | // attach to the request information about how to dial the upstream; |
| 1241 | // this is necessary because the information cannot be sufficiently |
| 1242 | // or satisfactorily represented in a URL |
| 1243 | // it's set before request is roundtripped to avoid a race condition when |
| 1244 | // http.Transport reads a newer value to dial a new connection when that new |
| 1245 | // value is updated by another reverse proxy handler, typically forward_auth. |
| 1246 | ctx := context.WithValue(req.Context(), dialInfoCtxKey, di) |
| 1247 | // Record the upstream socket for the websocket close message, since an |
| 1248 | // upgraded HTTP/1 body hides it; see upstreamWriteCloser. |
| 1249 | if isWebsocket(req) { |
| 1250 | upstreamConn := new(atomic.Pointer[net.Conn]) |
| 1251 | trace.GotConn = func(info httptrace.GotConnInfo) { |
| 1252 | conn := info.Conn |
| 1253 | upstreamConn.Store(&conn) |
| 1254 | } |
| 1255 | ctx = context.WithValue(ctx, upstreamConnCtxKey, upstreamConn) |
| 1256 | } |
| 1257 | req = req.WithContext(httptrace.WithClientTrace(ctx, trace)) |
| 1258 | |
| 1259 | // do the round-trip |
| 1260 | start := time.Now() |
| 1261 | res, err := h.roundTrip(req) |
| 1262 | duration := time.Since(start) |
| 1263 | |
| 1264 | // record that the round trip is done for the 1xx response handler |
| 1265 | roundTripMutex.Lock() |
| 1266 | roundTripDone = true |
| 1267 | roundTripMutex.Unlock() |
| 1268 | |
| 1269 | // emit debug log with values we know are safe, |
| 1270 | // or if there is no error, emit fuller log entry |
| 1271 | logger := h.logger.With( |
| 1272 | zap.String("upstream", di.Upstream.String()), |
| 1273 | zap.Duration("duration", duration), |
| 1274 | zap.Object("request", caddyhttp.LoggableHTTPRequest{ |
| 1275 | Request: req, |
| 1276 | ShouldLogCredentials: shouldLogCredentials, |
| 1277 | }), |
| 1278 | ) |
| 1279 | |
| 1280 | const logMessage = "upstream roundtrip" |
| 1281 | |
| 1282 | if err != nil { |
| 1283 | if c := logger.Check(zapcore.DebugLevel, logMessage); c != nil { |
| 1284 | c.Write(zap.Error(err)) |
| 1285 | } |
| 1286 | return err |
| 1287 | } |
| 1288 | if c := logger.Check(zapcore.DebugLevel, logMessage); c != nil { |
| 1289 | c.Write( |
| 1290 | zap.Object("headers", caddyhttp.LoggableHTTPHeader{ |
| 1291 | Header: res.Header, |
| 1292 | ShouldLogCredentials: shouldLogCredentials, |
| 1293 | }), |
| 1294 | zap.Int("status", res.StatusCode), |
| 1295 | ) |
| 1296 | } |
| 1297 | |
| 1298 | h.recordUpstreamRoundTrip(di, repl, res.StatusCode, duration) |
| 1299 | |
| 1300 | // if enabled, buffer the response body |
| 1301 | if h.ResponseBuffers != 0 && !caddyhttp.IsIncremental(res.Header) { |
| 1302 | res.Body, _ = h.bufferedBody(res.Body, h.ResponseBuffers) |
| 1303 | } |
| 1304 | |
| 1305 | // set response placeholders so they can be used in retry match |
| 1306 | // expressions and handle_response routes; clear stale header |
| 1307 | // placeholders from a previous attempt first so they don't |
| 1308 | // leak into the next retry evaluation |
| 1309 | repl.DeleteByPrefix("http.reverse_proxy.header.") |
| 1310 | for field, value := range res.Header { |
| 1311 | repl.Set("http.reverse_proxy.header."+field, strings.Join(value, ",")) |
| 1312 | } |
| 1313 | repl.Set("http.reverse_proxy.status_code", res.StatusCode) |
| 1314 | repl.Set("http.reverse_proxy.status_text", res.Status) |
| 1315 | |
| 1316 | // check if the response matches a retry match entry; if so, |
| 1317 | // close the body and return a retryable error so the request |
| 1318 | // is retried with the next upstream. Only evaluate matcher sets |
| 1319 | // with an expression that references response data ({rp.status_code}, |
| 1320 | // {rp.header.*}). Request-only matchers (method, path, or an |
| 1321 | // expression without response placeholders) are skipped to avoid |
| 1322 | // retrying every response that matches a request condition |
| 1323 | if h.LoadBalancing != nil && len(h.LoadBalancing.RetryMatch) > 0 { |
| 1324 | for _, matcherSet := range h.LoadBalancing.RetryMatch { |
| 1325 | if !matcherSetReferencesResponse(matcherSet) { |
| 1326 | continue |
| 1327 | } |
| 1328 | match, err := matcherSet.MatchWithError(req) |
| 1329 | if err != nil { |
| 1330 | h.logger.Error("error matching request for retry", zap.Error(err)) |
| 1331 | break |
| 1332 | } |
| 1333 | if match { |
| 1334 | res.Body.Close() |
| 1335 | return retryableResponseError{ |
| 1336 | error: fmt.Errorf("upstream response matched retry_match (status %d)", res.StatusCode), |
| 1337 | statusCode: res.StatusCode, |
| 1338 | } |
| 1339 | } |
| 1340 | } |
| 1341 | } |
| 1342 | |
| 1343 | // see if any response handler is configured for this response from the backend |
| 1344 | for i, rh := range h.HandleResponse { |
| 1345 | if rh.Match != nil && !rh.Match.Match(res.StatusCode, res.Header) { |
| 1346 | continue |
| 1347 | } |
| 1348 | |
| 1349 | // if configured to only change the status code, |
| 1350 | // do that then continue regular proxy response |
| 1351 | if statusCodeStr := rh.StatusCode.String(); statusCodeStr != "" { |
| 1352 | statusCode, err := strconv.Atoi(repl.ReplaceAll(statusCodeStr, "")) |
| 1353 | if err != nil { |
| 1354 | res.Body.Close() |
| 1355 | return caddyhttp.Error(http.StatusInternalServerError, err) |
| 1356 | } |
| 1357 | if statusCode != 0 { |
| 1358 | res.StatusCode = statusCode |
| 1359 | } |
| 1360 | break |
| 1361 | } |
| 1362 | |
| 1363 | if c := logger.Check(zapcore.DebugLevel, "handling response"); c != nil { |
| 1364 | c.Write(zap.Int("handler", i)) |
| 1365 | } |
| 1366 | |
| 1367 | // we make some data available via request context to child routes |
| 1368 | // so that they may inherit some options and functions from the |
| 1369 | // handler, and be able to copy the response. |
| 1370 | // we use the original request here, so that any routes from 'next' |
| 1371 | // see the original request rather than the proxy cloned request. |
| 1372 | hrc := &handleResponseContext{ |
| 1373 | handler: h, |
| 1374 | response: res, |
| 1375 | start: start, |
| 1376 | logger: logger, |
| 1377 | upstreamAddr: di.Upstream.String(), |
| 1378 | } |
| 1379 | ctx := origReq.Context() |
| 1380 | ctx = context.WithValue(ctx, proxyHandleResponseContextCtxKey, hrc) |
| 1381 | |
| 1382 | // pass the request through the response handler routes |
| 1383 | routeErr := rh.Routes.Compile(next).ServeHTTP(rw, origReq.WithContext(ctx)) |
| 1384 | |
| 1385 | // close the response body afterwards, since we don't need it anymore; |
| 1386 | // either a route had 'copy_response' which already consumed the body, |
| 1387 | // or some other terminal handler ran which doesn't need the response |
| 1388 | // body after that point (e.g. 'file_server' for X-Accel-Redirect flow), |
| 1389 | // or we fell through to subsequent handlers past this proxy |
| 1390 | // (e.g. forward auth's 2xx response flow). |
| 1391 | if !hrc.isFinalized { |
| 1392 | res.Body.Close() |
| 1393 | } |
| 1394 | |
| 1395 | // wrap any route error in terminalError so the outer loop knows |
| 1396 | // the response is committed and must not be retried |
| 1397 | if routeErr != nil { |
| 1398 | return terminalError{routeErr} |
| 1399 | } |
| 1400 | |
| 1401 | // we're done handling the response, and we don't want to |
| 1402 | // fall through to the default finalize/copy behaviour |
| 1403 | return nil |
| 1404 | } |
| 1405 | |
| 1406 | // copy the response body and headers back to the upstream client |
| 1407 | return h.finalizeResponse(rw, req, res, repl, start, logger, di.Upstream.String()) |
| 1408 | } |
| 1409 | |
| 1410 | // finalizeResponse prepares and copies the response. |
| 1411 | func (h *Handler) finalizeResponse( |
| 1412 | rw http.ResponseWriter, |
| 1413 | req *http.Request, |
| 1414 | res *http.Response, |
| 1415 | repl *caddy.Replacer, |
| 1416 | start time.Time, |
| 1417 | logger *zap.Logger, |
| 1418 | upstreamAddr string, |
| 1419 | ) error { |
| 1420 | responseWasIncremental := caddyhttp.IsIncremental(res.Header) |
| 1421 | |
| 1422 | // Strip hop-by-hop headers from the upstream response. |
| 1423 | // For 101 Switching Protocols, save the Upgrade value |
| 1424 | // first (handleUpgradeResponse needs it for validation) |
| 1425 | // and restore it with a canonical Connection header. |
| 1426 | upgradeVal := res.Header.Get("Upgrade") |
| 1427 | |
| 1428 | stripHopByHopHeaders(res.Header) |
| 1429 | |
| 1430 | if res.StatusCode == http.StatusSwitchingProtocols && upgradeVal != "" { |
| 1431 | res.Header.Set("Upgrade", upgradeVal) |
| 1432 | res.Header.Set("Connection", "Upgrade") |
| 1433 | } |
| 1434 | |
| 1435 | // deal with 101 Switching Protocols responses: (WebSocket, h2c, etc) |
| 1436 | if res.StatusCode == http.StatusSwitchingProtocols { |
| 1437 | h.handleUpgradeResponse(logger, rw, req, res, upstreamAddr) |
| 1438 | return nil |
| 1439 | } |
| 1440 | |
| 1441 | // delete our Server header and use Via instead (see #6275) |
| 1442 | rwHeader := rw.Header() |
| 1443 | delete(rwHeader, "Server") |
| 1444 | var protoPrefix string |
| 1445 | if !strings.HasPrefix(strings.ToUpper(res.Proto), "HTTP/") { |
| 1446 | protoPrefix = res.Proto[:strings.Index(res.Proto, "/")+1] |
| 1447 | } |
| 1448 | rwHeader["Via"] = append(rwHeader["Via"], protoPrefix+strconv.Itoa(res.ProtoMajor)+"."+strconv.Itoa(res.ProtoMinor)+" Caddy") |
| 1449 | |
| 1450 | // apply any response header operations |
| 1451 | if h.Headers != nil && h.Headers.Response != nil { |
| 1452 | if h.Headers.Response.Require == nil || |
| 1453 | h.Headers.Response.Require.Match(res.StatusCode, res.Header) { |
| 1454 | h.Headers.Response.ApplyTo(res.Header, repl) |
| 1455 | } |
| 1456 | } |
| 1457 | if responseHasContent(req, res) && h.ResponseBuffers != 0 && |
| 1458 | (responseWasIncremental || caddyhttp.IsIncremental(res.Header)) { |
| 1459 | res.Body.Close() |
| 1460 | return terminalError{h.refuseIncremental(rw, res.Header)} |
| 1461 | } |
| 1462 | |
| 1463 | copyHeader(rw.Header(), res.Header) |
| 1464 | |
| 1465 | // The "Trailer" header isn't included in the Transport's response, |
| 1466 | // at least for *http.Transport. Build it up from Trailer. |
| 1467 | announcedTrailers := len(res.Trailer) |
| 1468 | if announcedTrailers > 0 { |
| 1469 | trailerKeys := make([]string, 0, len(res.Trailer)) |
| 1470 | for k := range res.Trailer { |
| 1471 | trailerKeys = append(trailerKeys, k) |
| 1472 | } |
| 1473 | rw.Header().Add("Trailer", strings.Join(trailerKeys, ", ")) |
| 1474 | } |
| 1475 | |
| 1476 | rw.WriteHeader(res.StatusCode) |
| 1477 | if h.VerboseLogs { |
| 1478 | logger.Debug("wrote header") |
| 1479 | } |
| 1480 | |
| 1481 | err := h.copyResponse(rw, res.Body, h.flushInterval(req, res, responseWasIncremental), logger) |
| 1482 | errClose := res.Body.Close() // close now, instead of defer, to populate res.Trailer |
| 1483 | if h.VerboseLogs || errClose != nil { |
| 1484 | if c := logger.Check(zapcore.DebugLevel, "closed response body from upstream"); c != nil { |
| 1485 | c.Write(zap.Error(errClose)) |
| 1486 | } |
| 1487 | } |
| 1488 | if err != nil { |
| 1489 | // we're streaming the response and we've already written headers, so |
| 1490 | // there's nothing an error handler can do to recover at this point; |
| 1491 | // we'll just log the error and abort the stream here and panic just as |
| 1492 | // the standard lib's proxy to propagate the stream error. |
| 1493 | // see issue https://github.com/caddyserver/caddy/issues/5951 |
| 1494 | lvl := zapcore.WarnLevel |
| 1495 | if isClientCanceledH3(err) { |
| 1496 | // the client canceled the request; expected and not actionable |
| 1497 | // see issue https://github.com/caddyserver/caddy/issues/5766 |
| 1498 | lvl = zapcore.DebugLevel |
| 1499 | } |
| 1500 | if c := logger.Check(lvl, "aborting with incomplete response"); c != nil { |
| 1501 | c.Write(zap.Error(err)) |
| 1502 | } |
| 1503 | // flush the buffer to ensure the client sees the partial response |
| 1504 | // see: https://github.com/caddyserver/caddy/issues/7845 |
| 1505 | //nolint:bodyclose |
| 1506 | http.NewResponseController(rw).Flush() |
| 1507 | // no extra logging from stdlib |
| 1508 | panic(http.ErrAbortHandler) |
| 1509 | } |
| 1510 | |
| 1511 | if len(res.Trailer) > 0 { |
| 1512 | // Force chunking if we saw a response trailer. |
| 1513 | // This prevents net/http from calculating the length for short |
| 1514 | // bodies and adding a Content-Length. |
| 1515 | //nolint:bodyclose |
| 1516 | http.NewResponseController(rw).Flush() |
| 1517 | } |
| 1518 | |
| 1519 | // total duration spent proxying, including writing response body |
| 1520 | repl.Set("http.reverse_proxy.upstream.duration", time.Since(start)) |
| 1521 | repl.Set("http.reverse_proxy.upstream.duration_ms", time.Since(start).Seconds()*1e3) |
| 1522 | |
| 1523 | if len(res.Trailer) == announcedTrailers { |
| 1524 | copyHeader(rw.Header(), res.Trailer) |
| 1525 | return nil |
| 1526 | } |
| 1527 | |
| 1528 | for k, vv := range res.Trailer { |
| 1529 | k = http.TrailerPrefix + k |
| 1530 | for _, v := range vv { |
| 1531 | rw.Header().Add(k, v) |
| 1532 | } |
| 1533 | } |
| 1534 | |
| 1535 | if h.VerboseLogs { |
| 1536 | logger.Debug("response finalized") |
| 1537 | } |
| 1538 | |
| 1539 | return nil |
| 1540 | } |
| 1541 | |
| 1542 | // isClientCanceledH3 returns true if err is an HTTP/3 client canceling |
| 1543 | // its request (H3_REQUEST_CANCELLED) while the response was being written. |
| 1544 | // The same error read from an HTTP/3 backend is the backend's doing. |
| 1545 | func isClientCanceledH3(err error) bool { |
| 1546 | if !errors.Is(err, errWritingDownstream) { |
| 1547 | return false |
| 1548 | } |
| 1549 | h3Err, ok := errors.AsType[*http3.Error](err) |
| 1550 | return ok && h3Err.Remote && h3Err.ErrorCode == http3.ErrCodeRequestCanceled |
| 1551 | } |
| 1552 | |
| 1553 | // tryAgain takes the time that the handler was initially invoked, |
| 1554 | // the amount of retries already performed, as well as any error |
| 1555 | // currently obtained, and the request being tried, and returns |
| 1556 | // true if another attempt should be made at proxying the request. |
| 1557 | // If true is returned, it has already blocked long enough before |
| 1558 | // the next retry (i.e. no more sleeping is needed). If false is |
| 1559 | // returned, the handler should stop trying to proxy the request. |
| 1560 | func (lb LoadBalancing) tryAgain(ctx caddy.Context, start time.Time, retries int, proxyErr error, req *http.Request, logger *zap.Logger) bool { |
| 1561 | // no retries are configured |
| 1562 | if lb.TryDuration == 0 && lb.Retries == 0 { |
| 1563 | return false |
| 1564 | } |
| 1565 | |
| 1566 | // if we've tried long enough, break |
| 1567 | if lb.TryDuration > 0 && time.Since(start) >= time.Duration(lb.TryDuration) { |
| 1568 | return false |
| 1569 | } |
| 1570 | |
| 1571 | // if we've reached the retry limit, break |
| 1572 | if lb.Retries > 0 && retries >= lb.Retries { |
| 1573 | return false |
| 1574 | } |
| 1575 | |
| 1576 | // if the error occurred while dialing (i.e. a connection |
| 1577 | // could not even be established to the upstream), then it |
| 1578 | // should be safe to retry, since without a connection, no |
| 1579 | // HTTP request can be transmitted; but if the error is not |
| 1580 | // specifically a dialer error, we need to be careful; the |
| 1581 | // dial error may be wrapped, e.g. net/http wraps it in a |
| 1582 | // *net.OpError ("proxyconnect") when a forward proxy is used |
| 1583 | if proxyErr != nil { |
| 1584 | var dialErr DialError |
| 1585 | isDialError := errors.As(proxyErr, &dialErr) |
| 1586 | _, isRetryableResponse := proxyErr.(retryableResponseError) |
| 1587 | herr, isHandlerError := proxyErr.(caddyhttp.HandlerError) |
| 1588 | |
| 1589 | // if the error occurred after a connection was established, |
| 1590 | // we have to assume the upstream received the request, and |
| 1591 | // retries need to be carefully decided, because some requests |
| 1592 | // are not idempotent; retryableResponseError is excluded here |
| 1593 | // because its retry decision was already made in reverseProxy() |
| 1594 | // when the response matchers were evaluated |
| 1595 | if !isDialError && !isRetryableResponse && (!isHandlerError || !errors.Is(herr, errNoUpstream)) { |
| 1596 | if lb.RetryMatch == nil && req.Method != "GET" { |
| 1597 | // by default, don't retry requests if they aren't GET |
| 1598 | return false |
| 1599 | } |
| 1600 | |
| 1601 | // set transport error flag so CEL expressions can use |
| 1602 | // {rp.is_transport_error} to decide whether to retry |
| 1603 | repl, _ := req.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer) |
| 1604 | if repl != nil { |
| 1605 | repl.Set("http.reverse_proxy.is_transport_error", true) |
| 1606 | defer repl.Delete("http.reverse_proxy.is_transport_error") |
| 1607 | } |
| 1608 | |
| 1609 | match, err := lb.RetryMatch.AnyMatchWithError(req) |
| 1610 | if err != nil { |
| 1611 | logger.Error("error matching request for retry", zap.Error(err)) |
| 1612 | return false |
| 1613 | } |
| 1614 | if !match { |
| 1615 | return false |
| 1616 | } |
| 1617 | } |
| 1618 | } |
| 1619 | |
| 1620 | // fast path; if the interval is zero, we don't need to wait |
| 1621 | if lb.TryInterval == 0 { |
| 1622 | return true |
| 1623 | } |
| 1624 | |
| 1625 | // otherwise, wait and try the next available host |
| 1626 | timer := time.NewTimer(time.Duration(lb.TryInterval)) |
| 1627 | select { |
| 1628 | case <-timer.C: |
| 1629 | return true |
| 1630 | case <-ctx.Done(): |
| 1631 | if !timer.Stop() { |
| 1632 | // if the timer has been stopped then read from the channel |
| 1633 | <-timer.C |
| 1634 | } |
| 1635 | return false |
| 1636 | } |
| 1637 | } |
| 1638 | |
| 1639 | // newTracedTransport wraps rt so that round trips are recorded as |
| 1640 | // OpenTelemetry client spans. The tracer provider is taken from the span |
| 1641 | // in the request context (set by the tracing handler), so the wrapper does |
| 1642 | // not depend on any global tracer provider. |
| 1643 | func newTracedTransport(rt http.RoundTripper) http.RoundTripper { |
| 1644 | return otelhttp.NewTransport(rt, |
| 1645 | otelhttp.WithPropagators(autoprop.NewTextMapPropagator()), |
| 1646 | ) |
| 1647 | } |
| 1648 | |
| 1649 | // roundTrip sends req to the upstream. If req carries a valid span context, |
| 1650 | // the round trip is recorded as an OpenTelemetry client span and that span's |
| 1651 | // context is propagated to the upstream. |
| 1652 | func (h *Handler) roundTrip(req *http.Request) (*http.Response, error) { |
| 1653 | if h.tracedTransport == nil || !oteltrace.SpanContextFromContext(req.Context()).IsValid() { |
| 1654 | return h.Transport.RoundTrip(req) |
| 1655 | } |
| 1656 | // the traced transport clones req, so set the scheme beforehand |
| 1657 | // to keep it visible to the span attributes and to req itself |
| 1658 | if ss, ok := h.Transport.(interface{ SetScheme(*http.Request) }); ok { |
| 1659 | ss.SetScheme(req) |
| 1660 | } |
| 1661 | return h.tracedTransport.RoundTrip(req) |
| 1662 | } |
| 1663 | |
| 1664 | // directRequest modifies only req.URL so that it points to the upstream |
| 1665 | // in the given DialInfo. It must modify ONLY the request URL. |
| 1666 | func (h *Handler) directRequest(req *http.Request, di DialInfo) { |
| 1667 | // we need a host, so set the upstream's host address |
| 1668 | reqHost := di.Address |
| 1669 | |
| 1670 | // if the port equates to the scheme, strip the port because |
| 1671 | // it's weird to make a request like http://example.com:80/. |
| 1672 | if (req.URL.Scheme == "http" && di.Port == "80") || |
| 1673 | (req.URL.Scheme == "https" && di.Port == "443") { |
| 1674 | reqHost = di.Host |
| 1675 | } |
| 1676 | |
| 1677 | // add client address to the host to let transport differentiate requests from different clients |
| 1678 | if ppt, ok := h.Transport.(ProxyProtocolTransport); ok && ppt.ProxyProtocolEnabled() { |
| 1679 | if proxyProtocolInfo, ok := caddyhttp.GetVar(req.Context(), proxyProtocolInfoVarKey).(ProxyProtocolInfo); ok { |
| 1680 | // encode the request so it plays well with h2 transport, it's unnecessary for h1 but anyway |
| 1681 | // The issue is that h2 transport will use the address to determine if new connections are needed |
| 1682 | // to roundtrip requests but the without escaping, new connections are constantly created and closed until |
| 1683 | // file descriptors are exhausted. |
| 1684 | // see: https://github.com/caddyserver/caddy/issues/7529 |
| 1685 | reqHost = url.QueryEscape(proxyProtocolInfo.AddrPort.String() + "->" + reqHost) |
| 1686 | } |
| 1687 | } |
| 1688 | |
| 1689 | req.URL.Host = reqHost |
| 1690 | } |
| 1691 | |
| 1692 | func (h Handler) provisionUpstream(upstream *Upstream, dynamic bool) { |
| 1693 | // create or get the host representation for this upstream; |
| 1694 | // dynamic upstreams are tracked in a separate map with last-seen |
| 1695 | // timestamps so their health state persists across requests without |
| 1696 | // being reference-counted (and thus discarded between requests). |
| 1697 | if dynamic { |
| 1698 | upstream.fillDynamicHost() |
| 1699 | } else { |
| 1700 | upstream.fillHost() |
| 1701 | } |
| 1702 | |
| 1703 | // give it the circuit breaker, if any |
| 1704 | upstream.cb = h.CB |
| 1705 | |
| 1706 | // if the passive health checker has a non-zero UnhealthyRequestCount |
| 1707 | // but the upstream has no MaxRequests set (they are the same thing, |
| 1708 | // but the passive health checker is a default value for upstreams |
| 1709 | // without MaxRequests), copy the value into this upstream, since the |
| 1710 | // value in the upstream (MaxRequests) is what is used during |
| 1711 | // availability checks |
| 1712 | if h.HealthChecks != nil && |
| 1713 | h.HealthChecks.Passive != nil && |
| 1714 | h.HealthChecks.Passive.UnhealthyRequestCount > 0 && |
| 1715 | upstream.MaxRequests == 0 { |
| 1716 | upstream.MaxRequests = h.HealthChecks.Passive.UnhealthyRequestCount |
| 1717 | } |
| 1718 | |
| 1719 | // upstreams need independent access to the passive |
| 1720 | // health check policy because passive health checks |
| 1721 | // run without access to h. |
| 1722 | if h.HealthChecks != nil { |
| 1723 | upstream.healthCheckPolicy = h.HealthChecks.Passive |
| 1724 | } |
| 1725 | } |
| 1726 | |
| 1727 | // bufferedBody reads originalBody into a buffer with maximum size of limit (-1 for unlimited), |
| 1728 | // then returns a reader for the buffer along with how many bytes were buffered. Always close |
| 1729 | // the return value when done with it, just like if it was the original body! If limit is 0 |
| 1730 | // (which it shouldn't be), this function returns its input; i.e. is a no-op, for safety. |
| 1731 | // Otherwise, it returns bodyReadCloser, the original body will be closed and body will be nil |
| 1732 | // if it's explicitly configured to buffer all or EOF is reached when reading. |
| 1733 | // If reading fails, the body is returned as partially buffered, so the read error |
| 1734 | // is not hidden from the caller. |
| 1735 | func (h Handler) bufferedBody(originalBody io.ReadCloser, limit int64) (io.ReadCloser, int64) { |
| 1736 | if limit == 0 { |
| 1737 | return originalBody, 0 |
| 1738 | } |
| 1739 | var written int64 |
| 1740 | var err error |
| 1741 | buf := bufPool.Get().(*bytes.Buffer) |
| 1742 | buf.Reset() |
| 1743 | if limit > 0 { |
| 1744 | written, err = io.CopyN(buf, originalBody, limit) |
| 1745 | } else { |
| 1746 | written, err = io.Copy(buf, originalBody) |
| 1747 | } |
| 1748 | if (err != nil && err != io.EOF) || written == limit { |
| 1749 | return bodyReadCloser{ |
| 1750 | Reader: io.MultiReader(buf, originalBody), |
| 1751 | buf: buf, |
| 1752 | body: originalBody, |
| 1753 | }, written |
| 1754 | } |
| 1755 | originalBody.Close() // no point in keeping it open |
| 1756 | return bodyReadCloser{ |
| 1757 | Reader: buf, |
| 1758 | buf: buf, |
| 1759 | }, written |
| 1760 | } |
| 1761 | |
| 1762 | // requestBodyWithTrailers publishes a snapshot of the incoming trailers at EOF. |
| 1763 | // Close only closes the underlying body; it must not read or publish trailers. |
| 1764 | type requestBodyWithTrailers struct { |
| 1765 | io.ReadCloser |
| 1766 | original *http.Request |
| 1767 | trailer http.Header |
| 1768 | } |
| 1769 | |
| 1770 | func (b *requestBodyWithTrailers) Read(p []byte) (int, error) { |
| 1771 | n, err := b.ReadCloser.Read(p) |
| 1772 | if err == io.EOF && b.original != nil { |
| 1773 | clear(b.trailer) |
| 1774 | for k, vv := range b.original.Trailer { |
| 1775 | b.trailer[k] = slices.Clone(vv) |
| 1776 | } |
| 1777 | b.original = nil // repeated EOF reads must not recopy or append values |
| 1778 | } |
| 1779 | return n, err |
| 1780 | } |
| 1781 | |
| 1782 | // cloneRequest makes a semi-deep clone of origReq. |
| 1783 | // |
| 1784 | // Most of this code is borrowed from the Go stdlib reverse proxy, |
| 1785 | // but we make a shallow-ish clone the request (deep clone only |
| 1786 | // the headers and URL) so we can avoid manipulating the original |
| 1787 | // request when using it to proxy upstream. This prevents request |
| 1788 | // corruption and data races. |
| 1789 | func cloneRequest(origReq *http.Request) *http.Request { |
| 1790 | req := new(http.Request) |
| 1791 | *req = *origReq |
| 1792 | if origReq.URL != nil { |
| 1793 | newURL := new(url.URL) |
| 1794 | *newURL = *origReq.URL |
| 1795 | if origReq.URL.User != nil { |
| 1796 | newURL.User = new(url.Userinfo) |
| 1797 | *newURL.User = *origReq.URL.User |
| 1798 | } |
| 1799 | // sanitize the request URL; we expect it to not contain the |
| 1800 | // scheme and host since those should be determined by r.TLS |
| 1801 | // and r.Host respectively, but some clients may include it |
| 1802 | // in the request-line, which is technically valid in HTTP, |
| 1803 | // but breaks reverseproxy behaviour, overriding how the |
| 1804 | // dialer will behave. See #4237 for context. |
| 1805 | newURL.Scheme = "" |
| 1806 | newURL.Host = "" |
| 1807 | req.URL = newURL |
| 1808 | } |
| 1809 | if origReq.Header != nil { |
| 1810 | req.Header = origReq.Header.Clone() |
| 1811 | } |
| 1812 | if origReq.Trailer != nil { |
| 1813 | req.Trailer = origReq.Trailer.Clone() |
| 1814 | } |
| 1815 | return req |
| 1816 | } |
| 1817 | |
| 1818 | func copyHeader(dst, src http.Header) { |
| 1819 | for k, vv := range src { |
| 1820 | for _, v := range vv { |
| 1821 | dst.Add(k, v) |
| 1822 | } |
| 1823 | } |
| 1824 | } |
| 1825 | |
| 1826 | // recordUpstreamRoundTrip publishes latency placeholders, records circuit |
| 1827 | // breaker metrics, and applies passive health-check strikes for one |
| 1828 | // completed upstream attempt. Used by both the HTTP round-trip path and |
| 1829 | // the WebTransport hijack path. |
| 1830 | func (h *Handler) recordUpstreamRoundTrip(di DialInfo, repl *caddy.Replacer, status int, duration time.Duration) { |
| 1831 | repl.Set("http.reverse_proxy.upstream.latency", duration) |
| 1832 | repl.Set("http.reverse_proxy.upstream.latency_ms", duration.Seconds()*1e3) // multiply seconds to preserve decimal (see #4666) |
| 1833 | |
| 1834 | if di.Upstream != nil && di.Upstream.cb != nil { |
| 1835 | di.Upstream.cb.RecordMetric(status, duration) |
| 1836 | } |
| 1837 | |
| 1838 | if h.HealthChecks != nil && h.HealthChecks.Passive != nil { |
| 1839 | for _, badStatus := range h.HealthChecks.Passive.UnhealthyStatus { |
| 1840 | if caddyhttp.StatusCodeMatches(status, badStatus) { |
| 1841 | h.countFailure(di.Upstream) |
| 1842 | } |
| 1843 | } |
| 1844 | if h.HealthChecks.Passive.UnhealthyLatency > 0 && |
| 1845 | duration >= time.Duration(h.HealthChecks.Passive.UnhealthyLatency) { |
| 1846 | h.countFailure(di.Upstream) |
| 1847 | } |
| 1848 | } |
| 1849 | } |
| 1850 | |
| 1851 | // allHeaderValues gets all values for a given header field, |
| 1852 | // joined by a comma and space if more than one is set. If the |
| 1853 | // header field is nil, then the omit is true, meaning some |
| 1854 | // earlier logic in the server wanted to prevent this header from |
| 1855 | // getting written at all. If the header is empty, then ok is |
| 1856 | // false. Callers should still check that the value is not empty |
| 1857 | // (the header field may be set but have an empty value). |
| 1858 | func allHeaderValues(h http.Header, field string) (value string, ok bool, omit bool) { |
| 1859 | values, ok := h[http.CanonicalHeaderKey(field)] |
| 1860 | if ok && values == nil { |
| 1861 | return "", true, true |
| 1862 | } |
| 1863 | if len(values) == 0 { |
| 1864 | return "", false, false |
| 1865 | } |
| 1866 | return strings.Join(values, ", "), true, false |
| 1867 | } |
| 1868 | |
| 1869 | // lastHeaderValue gets the last value for a given header field |
| 1870 | // if more than one is set. If the header field is nil, then |
| 1871 | // the omit is true, meaning some earlier logic in the server |
| 1872 | // wanted to prevent this header from getting written at all. |
| 1873 | // If the header is empty, then ok is false. Callers should |
| 1874 | // still check that the value is not empty (the header field |
| 1875 | // may be set but have an empty value). |
| 1876 | func lastHeaderValue(h http.Header, field string) (value string, ok bool, omit bool) { |
| 1877 | values, ok := h[http.CanonicalHeaderKey(field)] |
| 1878 | if ok && values == nil { |
| 1879 | return "", true, true |
| 1880 | } |
| 1881 | if len(values) == 0 { |
| 1882 | return "", false, false |
| 1883 | } |
| 1884 | return values[len(values)-1], true, false |
| 1885 | } |
| 1886 | |
| 1887 | func upgradeType(h http.Header) string { |
| 1888 | if !httpguts.HeaderValuesContainsToken(h["Connection"], "Upgrade") { |
| 1889 | return "" |
| 1890 | } |
| 1891 | if v := h["Upgrade"]; len(v) > 0 { |
| 1892 | return strings.ToLower(v[0]) |
| 1893 | } |
| 1894 | return "" |
| 1895 | } |
| 1896 | |
| 1897 | // removeConnectionHeaders removes hop-by-hop headers listed in the "Connection" header of h. |
| 1898 | // See RFC 7230, section 6.1 |
| 1899 | func removeConnectionHeaders(h http.Header) { |
| 1900 | for _, f := range h["Connection"] { |
| 1901 | for sf := range strings.SplitSeq(f, ",") { |
| 1902 | if sf = textproto.TrimString(sf); sf != "" { |
| 1903 | h.Del(sf) |
| 1904 | } |
| 1905 | } |
| 1906 | } |
| 1907 | } |
| 1908 | |
| 1909 | // stripHopByHopHeaders removes hop-by-hop headers from h, including any |
| 1910 | // headers nominated by the Connection header. |
| 1911 | // See RFC 7230, section 6.1. |
| 1912 | func stripHopByHopHeaders(h http.Header) { |
| 1913 | removeConnectionHeaders(h) |
| 1914 | for _, hop := range hopHeaders { |
| 1915 | h.Del(hop) |
| 1916 | } |
| 1917 | } |
| 1918 | |
| 1919 | // statusError returns an error value that has a status code. |
| 1920 | func statusError(err error) error { |
| 1921 | // if a response-based retry was exhausted, use the actual upstream |
| 1922 | // status code instead of a generic 502 |
| 1923 | if rre, ok := err.(retryableResponseError); ok { |
| 1924 | return caddyhttp.Error(rre.statusCode, err) |
| 1925 | } |
| 1926 | |
| 1927 | // errors proxying usually mean there is a problem with the upstream(s) |
| 1928 | statusCode := http.StatusBadGateway |
| 1929 | |
| 1930 | // timeout errors have a standard status code (see issue #4823) |
| 1931 | if err, ok := err.(net.Error); ok && err.Timeout() { |
| 1932 | statusCode = http.StatusGatewayTimeout |
| 1933 | } |
| 1934 | |
| 1935 | // if the client canceled the request (usually this means they closed |
| 1936 | // the connection, so they won't see any response), we can report it |
| 1937 | // as a client error (4xx) and not a server error (5xx); unfortunately |
| 1938 | // the Go standard library, at least at time of writing in late 2020, |
| 1939 | // obnoxiously wraps the exported, standard context.Canceled error with |
| 1940 | // an unexported garbage value that we have to do a substring check for: |
| 1941 | // https://github.com/golang/go/blob/6965b01ea248cabb70c3749fd218b36089a21efb/src/net/net.go#L416-L430 |
| 1942 | if errors.Is(err, context.Canceled) || strings.Contains(err.Error(), "operation was canceled") { |
| 1943 | // regrettably, there is no standard error code for "client closed connection", but |
| 1944 | // for historical reasons we can use a code that a lot of people are already using; |
| 1945 | // using 5xx is problematic for users; see #3748 |
| 1946 | statusCode = 499 |
| 1947 | } |
| 1948 | return caddyhttp.Error(statusCode, err) |
| 1949 | } |
| 1950 | |
| 1951 | // LoadBalancing has parameters related to load balancing. |
| 1952 | type LoadBalancing struct { |
| 1953 | // A selection policy is how to choose an available backend. |
| 1954 | // The default policy is random selection. |
| 1955 | SelectionPolicyRaw json.RawMessage `json:"selection_policy,omitempty" caddy:"namespace=http.reverse_proxy.selection_policies inline_key=policy"` |
| 1956 | |
| 1957 | // How many times to retry selecting available backends for each |
| 1958 | // request if the next available host is down. If try_duration is |
| 1959 | // also configured, then retries may stop early if the duration |
| 1960 | // is reached. By default, retries are disabled (zero). |
| 1961 | Retries int `json:"retries,omitempty"` |
| 1962 | |
| 1963 | // How long to try selecting available backends for each request |
| 1964 | // if the next available host is down. Clients will wait for up |
| 1965 | // to this long while the load balancer tries to find an available |
| 1966 | // upstream host. If retries is also configured, tries may stop |
| 1967 | // early if the maximum retries is reached. By default, retries |
| 1968 | // are disabled (zero duration). |
| 1969 | TryDuration caddy.Duration `json:"try_duration,omitempty"` |
| 1970 | |
| 1971 | // How long to wait between selecting the next host from the pool. |
| 1972 | // Default is 250ms if try_duration is enabled, otherwise zero. Only |
| 1973 | // relevant when a request to an upstream host fails. Be aware that |
| 1974 | // setting this to 0 with a non-zero try_duration can cause the CPU |
| 1975 | // to spin if all backends are down and latency is very low. |
| 1976 | TryInterval caddy.Duration `json:"try_interval,omitempty"` |
| 1977 | |
| 1978 | // A list of matcher sets that controls retry behavior. Matcher sets |
| 1979 | // without expression matchers (e.g. method, path) restrict which |
| 1980 | // requests are retried on transport errors - if unspecified, only |
| 1981 | // GET requests will be retried. Matcher sets with CEL expression |
| 1982 | // matchers are evaluated against upstream responses and can |
| 1983 | // reference {rp.status_code}, {rp.header.*}, and |
| 1984 | // {rp.is_transport_error}. Dial errors are always retried |
| 1985 | // regardless of this setting. Retries use the next available |
| 1986 | // upstream per the load balancing policy |
| 1987 | RetryMatchRaw caddyhttp.RawMatcherSets `json:"retry_match,omitempty" caddy:"namespace=http.matchers"` |
| 1988 | |
| 1989 | SelectionPolicy Selector `json:"-"` |
| 1990 | RetryMatch caddyhttp.MatcherSets `json:"-"` |
| 1991 | } |
| 1992 | |
| 1993 | // Selector selects an available upstream from the pool. |
| 1994 | type Selector interface { |
| 1995 | Select(UpstreamPool, *http.Request, http.ResponseWriter) *Upstream |
| 1996 | } |
| 1997 | |
| 1998 | // UpstreamSource gets the list of upstreams that can be used when |
| 1999 | // proxying a request. Returned upstreams will be load balanced and |
| 2000 | // health-checked. This should be a very fast function -- instant |
| 2001 | // if possible -- and the return value must be as stable as possible. |
| 2002 | // In other words, the list of upstreams should ideally not change much |
| 2003 | // across successive calls. If the list of upstreams changes or the |
| 2004 | // ordering is not stable, load balancing will suffer. This function |
| 2005 | // may be called during each retry, multiple times per request, and as |
| 2006 | // such, needs to be instantaneous. The returned slice will not be |
| 2007 | // modified. |
| 2008 | // |
| 2009 | // For upstream sources that cache results, implement the |
| 2010 | // [CachingUpstreamSource] interface for optimal performance. |
| 2011 | type UpstreamSource interface { |
| 2012 | GetUpstreams(*http.Request) ([]*Upstream, error) |
| 2013 | } |
| 2014 | |
| 2015 | // CachingUpstreamSource is an upstream source that caches its upstreams. |
| 2016 | // The relevant cache entry can be cleared/reset for a given request during |
| 2017 | // retries if a request fails. This can help ensure that failing backends |
| 2018 | // are not retried. |
| 2019 | // |
| 2020 | // EXPERIMENTAL: Subject to change. |
| 2021 | type CachingUpstreamSource interface { |
| 2022 | UpstreamSource |
| 2023 | |
| 2024 | // ResetCache clears any cache entry related to the given request. |
| 2025 | // The next time GetUpstreams is called, it should have new upstream |
| 2026 | // information for the given request. |
| 2027 | ResetCache(*http.Request) error |
| 2028 | } |
| 2029 | |
| 2030 | // Hop-by-hop headers. These are removed when sent to the backend. |
| 2031 | // As of RFC 7230, hop-by-hop headers are required to appear in the |
| 2032 | // Connection header field. These are the headers defined by the |
| 2033 | // obsoleted RFC 2616 (section 13.5.1) and are used for backward |
| 2034 | // compatibility. |
| 2035 | var hopHeaders = []string{ |
| 2036 | "Alt-Svc", |
| 2037 | "Connection", |
| 2038 | "Proxy-Connection", // non-standard but still sent by libcurl and rejected by e.g. google |
| 2039 | "Keep-Alive", |
| 2040 | "Proxy-Authenticate", |
| 2041 | "Proxy-Authorization", |
| 2042 | "Te", // canonicalized version of "TE" |
| 2043 | "Trailer", // not Trailers per URL above; https://www.rfc-editor.org/errata_search.php?eid=4522 |
| 2044 | "Transfer-Encoding", |
| 2045 | "Upgrade", |
| 2046 | } |
| 2047 | |
| 2048 | // DialError is an error that specifically occurs |
| 2049 | // in a call to Dial or DialContext. |
| 2050 | type DialError struct{ error } |
| 2051 | |
| 2052 | // NewDialError wraps err as a DialError for transports outside this package. |
| 2053 | func NewDialError(err error) DialError { |
| 2054 | return DialError{err} |
| 2055 | } |
| 2056 | |
| 2057 | // TLSTransport is implemented by transports |
| 2058 | // that are capable of using TLS. |
| 2059 | type TLSTransport interface { |
| 2060 | // TLSEnabled returns true if the transport |
| 2061 | // has TLS enabled, false otherwise. |
| 2062 | TLSEnabled() bool |
| 2063 | |
| 2064 | // EnableTLS enables TLS within the transport |
| 2065 | // if it is not already, using the provided |
| 2066 | // value as a basis for the TLS config. |
| 2067 | EnableTLS(base *TLSConfig) error |
| 2068 | } |
| 2069 | |
| 2070 | // H2CTransport is implemented by transports |
| 2071 | // that are capable of using h2c. |
| 2072 | type H2CTransport interface { |
| 2073 | EnableH2C() error |
| 2074 | } |
| 2075 | |
| 2076 | // ProxyProtocolTransport is implemented by transports |
| 2077 | // that are capable of using proxy protocol. |
| 2078 | type ProxyProtocolTransport interface { |
| 2079 | ProxyProtocolEnabled() bool |
| 2080 | } |
| 2081 | |
| 2082 | // HealthCheckSchemeOverriderTransport is implemented by transports |
| 2083 | // that can override the scheme used for health checks. |
| 2084 | type HealthCheckSchemeOverriderTransport interface { |
| 2085 | OverrideHealthCheckScheme(base *url.URL, port string) |
| 2086 | } |
| 2087 | |
| 2088 | // proxyErrorIncrementalRefused is the Proxy-Status error type (RFC 9209) for |
| 2089 | // a message we refuse to forward incrementally, as registered by RFC 10036 |
| 2090 | // section 5. |
| 2091 | const proxyErrorIncrementalRefused = "incremental_refused" |
| 2092 | |
| 2093 | // errIncrementalRefused is the cause reported when a message asking for |
| 2094 | // incremental forwarding cannot be forwarded that way. |
| 2095 | var errIncrementalRefused = errors.New("refusing to forward the message incrementally") |
| 2096 | |
| 2097 | // refuseIncremental reports that a message asking for incremental forwarding |
| 2098 | // cannot be forwarded that way without overriding configured buffering or the |
| 2099 | // transport's framing requirements. RFC 10036 section 3 requires an error |
| 2100 | // response when incremental forwarding is refused. Section 4.1 recommends this |
| 2101 | // status and Proxy-Status error type. Upstream carries the headers of the |
| 2102 | // response being refused when present. This preserves its valid existing |
| 2103 | // members. |
| 2104 | func (h *Handler) refuseIncremental(rw http.ResponseWriter, upstream http.Header) error { |
| 2105 | if value, ok := h.proxyStatus(upstream, proxyErrorIncrementalRefused); ok { |
| 2106 | rw.Header().Set("Proxy-Status", value) |
| 2107 | } |
| 2108 | |
| 2109 | return caddyhttp.Error(http.StatusNotImplemented, errIncrementalRefused) |
| 2110 | } |
| 2111 | |
| 2112 | // proxyStatus builds a Proxy-Status field value (RFC 9209) reporting proxyErr, |
| 2113 | // appending this proxy to the members upstream already reported so the whole |
| 2114 | // chain stays visible. It reports false if no name identifies this deployment, |
| 2115 | // since a software name identifies no intermediary and generating the field at |
| 2116 | // all is optional. |
| 2117 | func (h *Handler) proxyStatus(upstream http.Header, proxyErr string) (string, bool) { |
| 2118 | if h.ProxyStatusName == "" { |
| 2119 | return "", false |
| 2120 | } |
| 2121 | |
| 2122 | // a malformed field from upstream is dropped rather than propagated |
| 2123 | list, err := httpsfv.UnmarshalList(upstream.Values("Proxy-Status")) |
| 2124 | if err != nil { |
| 2125 | list = httpsfv.List{} |
| 2126 | } |
| 2127 | for _, member := range list { |
| 2128 | item, ok := member.(httpsfv.Item) |
| 2129 | if !ok { |
| 2130 | list = httpsfv.List{} |
| 2131 | break |
| 2132 | } |
| 2133 | valid := false |
| 2134 | switch item.Value.(type) { |
| 2135 | case string, httpsfv.Token: |
| 2136 | valid = true |
| 2137 | } |
| 2138 | if !valid { |
| 2139 | list = httpsfv.List{} |
| 2140 | break |
| 2141 | } |
| 2142 | } |
| 2143 | |
| 2144 | // the name is a token where it can be, as the examples in RFC 9209 are, |
| 2145 | // and a string where a token cannot hold it (a space, say) |
| 2146 | item := httpsfv.NewItem(httpsfv.Token(h.ProxyStatusName)) |
| 2147 | item.Params.Add("error", httpsfv.Token(proxyErr)) |
| 2148 | if _, err := httpsfv.Marshal(item); err != nil { |
| 2149 | item.Value = h.ProxyStatusName |
| 2150 | } |
| 2151 | |
| 2152 | value, err := httpsfv.Marshal(append(list, item)) |
| 2153 | if err != nil { |
| 2154 | return "", false |
| 2155 | } |
| 2156 | |
| 2157 | return value, true |
| 2158 | } |
| 2159 | |
| 2160 | // responseHasContent reports whether res can carry content for req. This uses |
| 2161 | // the response semantics as well as Body because custom transports are not |
| 2162 | // required to represent an empty body with http.NoBody. |
| 2163 | func responseHasContent(req *http.Request, res *http.Response) bool { |
| 2164 | if req.Method == http.MethodHead || res.Body == nil || res.Body == http.NoBody || res.ContentLength == 0 { |
| 2165 | return false |
| 2166 | } |
| 2167 | if req.Method == http.MethodConnect && res.StatusCode >= 200 && res.StatusCode < 300 { |
| 2168 | return false |
| 2169 | } |
| 2170 | if res.StatusCode >= 100 && res.StatusCode < 200 || |
| 2171 | res.StatusCode == http.StatusNoContent || res.StatusCode == http.StatusResetContent || |
| 2172 | res.StatusCode == http.StatusNotModified { |
| 2173 | return false |
| 2174 | } |
| 2175 | return true |
| 2176 | } |
| 2177 | |
| 2178 | // requestHasContent reports whether r may carry content that matters for |
| 2179 | // incremental forwarding. HTTP/3 uses an unknown length for bodyless GET and |
| 2180 | // HEAD requests (see issue #6678), so their usual no-body semantics are used |
| 2181 | // rather than waiting for the request stream to end. |
| 2182 | func requestHasContent(r *http.Request) bool { |
| 2183 | if r.ContentLength > 0 { |
| 2184 | return true |
| 2185 | } |
| 2186 | if r.ContentLength == 0 { |
| 2187 | return false |
| 2188 | } |
| 2189 | |
| 2190 | switch r.Method { |
| 2191 | case http.MethodGet, http.MethodHead, http.MethodOptions, |
| 2192 | http.MethodDelete, http.MethodTrace, http.MethodConnect: |
| 2193 | return false |
| 2194 | } |
| 2195 | |
| 2196 | return true |
| 2197 | } |
| 2198 | |
| 2199 | func normalizeIncrementalRequest(req *http.Request) { |
| 2200 | if caddyhttp.IsIncremental(req.Header) && !requestHasContent(req) { |
| 2201 | // HTTP/3 can represent a bodyless GET or HEAD with an unknown length. |
| 2202 | // Do not pass that sentinel to transports that require framing. |
| 2203 | req.ContentLength = 0 |
| 2204 | req.Body = nil |
| 2205 | } |
| 2206 | } |
| 2207 | |
| 2208 | // incrementalRequestConflicts reports whether honouring an incremental request |
| 2209 | // would override an explicit buffer or violate the transport's framing needs. |
| 2210 | func (h *Handler) incrementalRequestConflicts(req *http.Request) bool { |
| 2211 | if !requestHasContent(req) || !caddyhttp.IsIncremental(req.Header) { |
| 2212 | return false |
| 2213 | } |
| 2214 | needsLength := h.transportRequiresContentLength() |
| 2215 | if h.RequestBuffers != 0 { |
| 2216 | if !h.requestBuffersFromTransport || !needsLength { |
| 2217 | return true |
| 2218 | } |
| 2219 | } |
| 2220 | return req.ContentLength < 0 && needsLength |
| 2221 | } |
| 2222 | |
| 2223 | // ContentLengthRequiredTransport is implemented by transports that cannot |
| 2224 | // forward a request body whose length they do not know, and so need it |
| 2225 | // buffered in full when the request does not carry a Content-Length. |
| 2226 | type ContentLengthRequiredTransport interface { |
| 2227 | // RequiresContentLength returns true if the transport needs the length of |
| 2228 | // a request body before it can forward it. |
| 2229 | RequiresContentLength() bool |
| 2230 | } |
| 2231 | |
| 2232 | // transportRequiresContentLength reports whether the transport in use cannot |
| 2233 | // forward a request body of unknown length. |
| 2234 | func (h *Handler) transportRequiresContentLength() bool { |
| 2235 | clt, ok := h.Transport.(ContentLengthRequiredTransport) |
| 2236 | |
| 2237 | return ok && clt.RequiresContentLength() |
| 2238 | } |
| 2239 | |
| 2240 | // BufferedTransport is implemented by transports |
| 2241 | // that needs to buffer requests and/or responses. |
| 2242 | type BufferedTransport interface { |
| 2243 | // DefaultBufferSizes returns the default buffer sizes |
| 2244 | // for requests and responses, respectively if buffering isn't enabled. |
| 2245 | DefaultBufferSizes() (int64, int64) |
| 2246 | } |
| 2247 | |
| 2248 | // RequestHeaderOpsTransport may be implemented by a transport to provide |
| 2249 | // header operations to apply to requests immediately before the RoundTrip. |
| 2250 | // For example, overriding the default Host when TLS is enabled. |
| 2251 | type RequestHeaderOpsTransport interface { |
| 2252 | // RequestHeaderOps allows a transport to provide header operations |
| 2253 | // to apply to the request. The transport is asked at provision time |
| 2254 | // to return a HeaderOps (or nil) that will be applied before |
| 2255 | // user-configured header ops. |
| 2256 | RequestHeaderOps() *headers.HeaderOps |
| 2257 | } |
| 2258 | |
| 2259 | // responsePlaceholders are the placeholders that are only set once the |
| 2260 | // upstream round trip completes ({rp.status_code} is adapted to |
| 2261 | // {http.reverse_proxy.status_code}, and so on) |
| 2262 | var responsePlaceholders = []string{ |
| 2263 | "http.reverse_proxy.status_code", |
| 2264 | "http.reverse_proxy.status_text", |
| 2265 | "http.reverse_proxy.upstream.latency", |
| 2266 | "http.reverse_proxy.upstream.latency_ms", |
| 2267 | } |
| 2268 | |
| 2269 | // responseHeaderPlaceholderPrefix is the prefix of the response |
| 2270 | // header placeholders, {http.reverse_proxy.header.*} |
| 2271 | const responseHeaderPlaceholderPrefix = "http.reverse_proxy.header." |
| 2272 | |
| 2273 | // matcherSetReferencesResponse reports whether a matcher set contains an |
| 2274 | // expression matcher that reads response data, or a placeholder whose name |
| 2275 | // is only known at evaluation time. Other matcher sets only test request or |
| 2276 | // upstream selection properties and should not be evaluated for |
| 2277 | // response-based retry decisions |
| 2278 | func matcherSetReferencesResponse(matcherSet caddyhttp.MatcherSet) bool { |
| 2279 | for _, m := range matcherSet { |
| 2280 | expr, ok := m.(*caddyhttp.MatchExpression) |
| 2281 | if !ok { |
| 2282 | continue |
| 2283 | } |
| 2284 | for _, name := range expr.Placeholders() { |
| 2285 | if name == "" || |
| 2286 | slices.Contains(responsePlaceholders, name) || |
| 2287 | strings.HasPrefix(name, responseHeaderPlaceholderPrefix) { |
| 2288 | return true |
| 2289 | } |
| 2290 | } |
| 2291 | } |
| 2292 | return false |
| 2293 | } |
| 2294 | |
| 2295 | // terminalError signals that the proxy loop must stop and the wrapped |
| 2296 | // error must be propagated unchanged. It is emitted in any situation |
| 2297 | // where the handler has committed enough client-visible state that |
| 2298 | // retrying against another upstream would be unsafe — for example, a |
| 2299 | // handle_response route that ran after a successful round-trip, or a |
| 2300 | // WebTransport upgrade that already flushed 200 OK and hijacked the |
| 2301 | // stream. The inner error may be nil to signal terminal success. |
| 2302 | type terminalError struct{ error } |
| 2303 | |
| 2304 | func (e terminalError) Unwrap() error { return e.error } |
| 2305 | |
| 2306 | // retryableResponseError is returned when the upstream response matched |
| 2307 | // a retry_match entry, indicating the request should be retried with the |
| 2308 | // next upstream. It preserves the original status code so that if retries |
| 2309 | // are exhausted, the actual upstream status is reported instead of a |
| 2310 | // generic 502 |
| 2311 | type retryableResponseError struct { |
| 2312 | error |
| 2313 | statusCode int |
| 2314 | } |
| 2315 | |
| 2316 | // bodyReadCloser is a reader that, upon closing, will return |
| 2317 | // its buffer to the pool and close the underlying body reader. |
| 2318 | type bodyReadCloser struct { |
| 2319 | io.Reader |
| 2320 | buf *bytes.Buffer |
| 2321 | body io.ReadCloser |
| 2322 | } |
| 2323 | |
| 2324 | func (brc bodyReadCloser) Close() error { |
| 2325 | // Inside this package this will be set to nil for fully-buffered |
| 2326 | // requests due to the possibility of retrial. |
| 2327 | if brc.buf != nil { |
| 2328 | bufPool.Put(brc.buf) |
| 2329 | } |
| 2330 | // For fully-buffered bodies, body is nil, so Close is a no-op. |
| 2331 | if brc.body != nil { |
| 2332 | return brc.body.Close() |
| 2333 | } |
| 2334 | return nil |
| 2335 | } |
| 2336 | |
| 2337 | // StreamLogs controls logging for upgraded stream lifecycle events. |
| 2338 | type StreamLogs struct { |
| 2339 | // The minimum level at which stream lifecycle events are logged. |
| 2340 | // Supported values are debug, info, warn, and error. Default: debug. |
| 2341 | Level string `json:"level,omitempty"` |
| 2342 | |
| 2343 | // Logger name for stream lifecycle logs. Default: "http.handlers.reverse_proxy.stream". |
| 2344 | // Special value "access" uses the access logger namespace and, if set, |
| 2345 | // respects the first value in access_logger_names/log_name for the request. |
| 2346 | LoggerName string `json:"logger_name,omitempty"` |
| 2347 | |
| 2348 | // If true, suppresses the access log entry normally emitted when an |
| 2349 | // upgraded stream handshake completes and the request unwinds. |
| 2350 | SkipHandshake bool `json:"skip_handshake,omitempty"` |
| 2351 | } |
| 2352 | |
| 2353 | // bufPool is used for buffering requests and responses. |
| 2354 | var bufPool = sync.Pool{ |
| 2355 | New: func() any { |
| 2356 | return new(bytes.Buffer) |
| 2357 | }, |
| 2358 | } |
| 2359 | |
| 2360 | // handleResponseContext carries some contextual information about the |
| 2361 | // current proxy handling. |
| 2362 | type handleResponseContext struct { |
| 2363 | // handler is the active proxy handler instance, so that |
| 2364 | // routes like copy_response may inherit some config |
| 2365 | // options and have access to handler methods. |
| 2366 | handler *Handler |
| 2367 | |
| 2368 | // response is the actual response received from the proxy |
| 2369 | // roundtrip, to potentially be copied if a copy_response |
| 2370 | // handler is in the handle_response routes. |
| 2371 | response *http.Response |
| 2372 | |
| 2373 | // start is the time just before the proxy roundtrip was |
| 2374 | // performed, used for logging. |
| 2375 | start time.Time |
| 2376 | |
| 2377 | // logger is the prepared logger which is used to write logs |
| 2378 | // with the request, duration, and selected upstream attached. |
| 2379 | logger *zap.Logger |
| 2380 | |
| 2381 | // isFinalized is whether the response has been finalized, |
| 2382 | // i.e. copied and closed, to make sure that it doesn't |
| 2383 | // happen twice. |
| 2384 | isFinalized bool |
| 2385 | |
| 2386 | // upstreamAddr is the selected upstream address for this request. |
| 2387 | upstreamAddr string |
| 2388 | } |
| 2389 | |
| 2390 | // proxyHandleResponseContextCtxKey is the context key for the active proxy handler |
| 2391 | // so that handle_response routes can inherit some config options |
| 2392 | // from the proxy handler. |
| 2393 | const proxyHandleResponseContextCtxKey caddy.CtxKey = "reverse_proxy_handle_response_context" |
| 2394 | |
| 2395 | // errNoUpstream occurs when there are no upstream available. |
| 2396 | var errNoUpstream = fmt.Errorf("no upstreams available") |
| 2397 | |
| 2398 | const ( |
| 2399 | defaultStreamLogLevel = zapcore.DebugLevel |
| 2400 | defaultStreamLoggerName = "http.handlers.reverse_proxy.stream" |
| 2401 | streamLoggerNameUseAccess = "access" |
| 2402 | defaultAccessLoggerBase = "http.log.access" |
| 2403 | ) |
| 2404 | |
| 2405 | // Interface guards |
| 2406 | var ( |
| 2407 | _ caddy.Provisioner = (*Handler)(nil) |
| 2408 | _ caddy.CleanerUpper = (*Handler)(nil) |
| 2409 | _ caddyhttp.MiddlewareHandler = (*Handler)(nil) |
| 2410 | ) |