Fast and extensible multi-platform HTTP/1-2-3 web server with automatic HTTPS
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| 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 caddyhttp |
| 16 | |
| 17 | import ( |
| 18 | "encoding/json" |
| 19 | "fmt" |
| 20 | "net/http" |
| 21 | "slices" |
| 22 | "strings" |
| 23 | |
| 24 | "github.com/caddyserver/caddy/v2" |
| 25 | ) |
| 26 | |
| 27 | // Route consists of a set of rules for matching HTTP requests, |
| 28 | // a list of handlers to execute, and optional flow control |
| 29 | // parameters which customize the handling of HTTP requests |
| 30 | // in a highly flexible and performant manner. |
| 31 | type Route struct { |
| 32 | // Group is an optional name for a group to which this |
| 33 | // route belongs. Grouping a route makes it mutually |
| 34 | // exclusive with others in its group; if a route belongs |
| 35 | // to a group, only the first matching route in that group |
| 36 | // will be executed. |
| 37 | Group string `json:"group,omitempty"` |
| 38 | |
| 39 | // The matcher sets which will be used to qualify this |
| 40 | // route for a request (essentially the "if" statement |
| 41 | // of this route). Each matcher set is OR'ed, but matchers |
| 42 | // within a set are AND'ed together. |
| 43 | MatcherSetsRaw RawMatcherSets `json:"match,omitempty" caddy:"namespace=http.matchers"` |
| 44 | |
| 45 | // The list of handlers for this route. Upon matching a request, they are chained |
| 46 | // together in a middleware fashion: requests flow from the first handler to the last |
| 47 | // (top of the list to the bottom), with the possibility that any handler could stop |
| 48 | // the chain and/or return an error. Responses flow back through the chain (bottom of |
| 49 | // the list to the top) as they are written out to the client. |
| 50 | // |
| 51 | // Not all handlers call the next handler in the chain. For example, the reverse_proxy |
| 52 | // handler always sends a request upstream or returns an error. Thus, configuring |
| 53 | // handlers after reverse_proxy in the same route is illogical, since they would never |
| 54 | // be executed. You will want to put handlers which originate the response at the very |
| 55 | // end of your route(s). The documentation for a module should state whether it invokes |
| 56 | // the next handler, but sometimes it is common sense. |
| 57 | // |
| 58 | // Some handlers manipulate the response. Remember that requests flow down the list, and |
| 59 | // responses flow up the list. |
| 60 | // |
| 61 | // For example, if you wanted to use both `templates` and `encode` handlers, you would |
| 62 | // need to put `templates` after `encode` in your route, because responses flow up. |
| 63 | // Thus, `templates` will be able to parse and execute the plain-text response as a |
| 64 | // template, and then return it up to the `encode` handler which will then compress it |
| 65 | // into a binary format. |
| 66 | // |
| 67 | // If `templates` came before `encode`, then `encode` would write a compressed, |
| 68 | // binary-encoded response to `templates` which would not be able to parse the response |
| 69 | // properly. |
| 70 | // |
| 71 | // The correct order, then, is this: |
| 72 | // |
| 73 | // [ |
| 74 | // {"handler": "encode"}, |
| 75 | // {"handler": "templates"}, |
| 76 | // {"handler": "file_server"} |
| 77 | // ] |
| 78 | // |
| 79 | // The request flows ⬇️ DOWN (`encode` -> `templates` -> `file_server`). |
| 80 | // |
| 81 | // 1. First, `encode` will choose how to `encode` the response and wrap the response. |
| 82 | // 2. Then, `templates` will wrap the response with a buffer. |
| 83 | // 3. Finally, `file_server` will originate the content from a file. |
| 84 | // |
| 85 | // The response flows ⬆️ UP (`file_server` -> `templates` -> `encode`): |
| 86 | // |
| 87 | // 1. First, `file_server` will write the file to the response. |
| 88 | // 2. That write will be buffered and then executed by `templates`. |
| 89 | // 3. Lastly, the write from `templates` will flow into `encode` which will compress the stream. |
| 90 | // |
| 91 | // If you think of routes in this way, it will be easy and even fun to solve the puzzle of writing correct routes. |
| 92 | HandlersRaw []json.RawMessage `json:"handle,omitempty" caddy:"namespace=http.handlers inline_key=handler"` |
| 93 | |
| 94 | // If true, no more routes will be executed after this one. |
| 95 | Terminal bool `json:"terminal,omitempty"` |
| 96 | |
| 97 | // decoded values |
| 98 | MatcherSets MatcherSets `json:"-"` |
| 99 | Handlers []MiddlewareHandler `json:"-"` |
| 100 | |
| 101 | middleware []Middleware |
| 102 | metrics *Metrics |
| 103 | metricsCtx caddy.Context |
| 104 | handlerName string |
| 105 | } |
| 106 | |
| 107 | // Empty returns true if the route has all zero/default values. |
| 108 | func (r Route) Empty() bool { |
| 109 | return len(r.MatcherSetsRaw) == 0 && |
| 110 | len(r.MatcherSets) == 0 && |
| 111 | len(r.HandlersRaw) == 0 && |
| 112 | len(r.Handlers) == 0 && |
| 113 | !r.Terminal && |
| 114 | r.Group == "" |
| 115 | } |
| 116 | |
| 117 | func (r Route) String() string { |
| 118 | var handlersRaw strings.Builder |
| 119 | handlersRaw.WriteByte('[') |
| 120 | for _, hr := range r.HandlersRaw { |
| 121 | handlersRaw.WriteByte(' ') |
| 122 | handlersRaw.WriteString(string(hr)) |
| 123 | } |
| 124 | handlersRaw.WriteByte(']') |
| 125 | |
| 126 | return fmt.Sprintf(`{Group:"%s" MatcherSetsRaw:%s HandlersRaw:%s Terminal:%t}`, |
| 127 | r.Group, r.MatcherSetsRaw, handlersRaw.String(), r.Terminal) |
| 128 | } |
| 129 | |
| 130 | // Provision sets up both the matchers and handlers in the route. |
| 131 | func (r *Route) Provision(ctx caddy.Context, metrics *Metrics) error { |
| 132 | err := r.ProvisionMatchers(ctx) |
| 133 | if err != nil { |
| 134 | return err |
| 135 | } |
| 136 | return r.ProvisionHandlers(ctx, metrics) |
| 137 | } |
| 138 | |
| 139 | // ProvisionMatchers sets up all the matchers by loading the |
| 140 | // matcher modules. Only call this method directly if you need |
| 141 | // to set up matchers and handlers separately without having |
| 142 | // to provision a second time; otherwise use Provision instead. |
| 143 | func (r *Route) ProvisionMatchers(ctx caddy.Context) error { |
| 144 | // matchers |
| 145 | matchersIface, err := ctx.LoadModule(r, "MatcherSetsRaw") |
| 146 | if err != nil { |
| 147 | return fmt.Errorf("loading matcher modules: %v", err) |
| 148 | } |
| 149 | err = r.MatcherSets.FromInterface(matchersIface) |
| 150 | if err != nil { |
| 151 | return err |
| 152 | } |
| 153 | return nil |
| 154 | } |
| 155 | |
| 156 | // ProvisionHandlers sets up all the handlers by loading the |
| 157 | // handler modules. Only call this method directly if you need |
| 158 | // to set up matchers and handlers separately without having |
| 159 | // to provision a second time; otherwise use Provision instead. |
| 160 | func (r *Route) ProvisionHandlers(ctx caddy.Context, metrics *Metrics) error { |
| 161 | handlersIface, err := ctx.LoadModule(r, "HandlersRaw") |
| 162 | if err != nil { |
| 163 | return fmt.Errorf("loading handler modules: %v", err) |
| 164 | } |
| 165 | for _, handler := range handlersIface.([]any) { |
| 166 | r.Handlers = append(r.Handlers, handler.(MiddlewareHandler)) |
| 167 | } |
| 168 | |
| 169 | // Store metrics info for route-level instrumentation (applied once |
| 170 | // per route in wrapRoute, instead of per-handler which was redundant). |
| 171 | r.metrics = metrics |
| 172 | r.metricsCtx = ctx |
| 173 | if len(r.Handlers) > 0 { |
| 174 | r.handlerName = caddy.GetModuleName(r.Handlers[0]) |
| 175 | } |
| 176 | |
| 177 | // Make ProvisionHandlers idempotent by clearing the middleware field |
| 178 | r.middleware = []Middleware{} |
| 179 | |
| 180 | // pre-compile the middleware handler chain |
| 181 | for _, midhandler := range r.Handlers { |
| 182 | r.middleware = append(r.middleware, wrapMiddleware(ctx, midhandler)) |
| 183 | } |
| 184 | return nil |
| 185 | } |
| 186 | |
| 187 | // Compile prepares a middleware chain from the route list. |
| 188 | // This should only be done once during the request, just |
| 189 | // before the middleware chain is executed. |
| 190 | func (r Route) Compile(next Handler) Handler { |
| 191 | return wrapRoute(r)(next) |
| 192 | } |
| 193 | |
| 194 | // RouteList is a list of server routes that can |
| 195 | // create a middleware chain. |
| 196 | type RouteList []Route |
| 197 | |
| 198 | // Provision sets up both the matchers and handlers in the routes. |
| 199 | func (routes RouteList) Provision(ctx caddy.Context) error { |
| 200 | err := routes.ProvisionMatchers(ctx) |
| 201 | if err != nil { |
| 202 | return err |
| 203 | } |
| 204 | return routes.ProvisionHandlers(ctx, nil) |
| 205 | } |
| 206 | |
| 207 | // ProvisionMatchers sets up all the matchers by loading the |
| 208 | // matcher modules. Only call this method directly if you need |
| 209 | // to set up matchers and handlers separately without having |
| 210 | // to provision a second time; otherwise use Provision instead. |
| 211 | func (routes RouteList) ProvisionMatchers(ctx caddy.Context) error { |
| 212 | for i := range routes { |
| 213 | err := routes[i].ProvisionMatchers(ctx) |
| 214 | if err != nil { |
| 215 | return fmt.Errorf("route %d: %v", i, err) |
| 216 | } |
| 217 | } |
| 218 | return nil |
| 219 | } |
| 220 | |
| 221 | // ProvisionHandlers sets up all the handlers by loading the |
| 222 | // handler modules. Only call this method directly if you need |
| 223 | // to set up matchers and handlers separately without having |
| 224 | // to provision a second time; otherwise use Provision instead. |
| 225 | func (routes RouteList) ProvisionHandlers(ctx caddy.Context, metrics *Metrics) error { |
| 226 | for i := range routes { |
| 227 | err := routes[i].ProvisionHandlers(ctx, metrics) |
| 228 | if err != nil { |
| 229 | return fmt.Errorf("route %d: %v", i, err) |
| 230 | } |
| 231 | } |
| 232 | return nil |
| 233 | } |
| 234 | |
| 235 | // Compile prepares a middleware chain from the route list. |
| 236 | // This should only be done either once during provisioning |
| 237 | // for top-level routes, or on each request just before the |
| 238 | // middleware chain is executed for subroutes. |
| 239 | func (routes RouteList) Compile(next Handler) Handler { |
| 240 | mid := make([]Middleware, 0, len(routes)) |
| 241 | for _, route := range routes { |
| 242 | mid = append(mid, wrapRoute(route)) |
| 243 | } |
| 244 | stack := next |
| 245 | for _, middleware := range slices.Backward(mid) { |
| 246 | stack = middleware(stack) |
| 247 | } |
| 248 | return stack |
| 249 | } |
| 250 | |
| 251 | // wrapRoute wraps route with a middleware and handler so that it can |
| 252 | // be chained in and defer evaluation of its matchers to request-time. |
| 253 | // Like wrapMiddleware, it is vital that this wrapping takes place in |
| 254 | // its own stack frame so as to not overwrite the reference to the |
| 255 | // intended route by looping and changing the reference each time. |
| 256 | func wrapRoute(route Route) Middleware { |
| 257 | return func(next Handler) Handler { |
| 258 | return HandlerFunc(func(rw http.ResponseWriter, req *http.Request) error { |
| 259 | // TODO: Update this comment, it seems we've moved the copy into the handler? |
| 260 | // copy the next handler (it's an interface, so it's just |
| 261 | // a very lightweight copy of a pointer); this is important |
| 262 | // because this is a closure to the func below, which |
| 263 | // re-assigns the value as it compiles the middleware stack; |
| 264 | // if we don't make this copy, we'd affect the underlying |
| 265 | // pointer for all future request (yikes); we could |
| 266 | // alternatively solve this by moving the func below out of |
| 267 | // this closure and into a standalone package-level func, |
| 268 | // but I just thought this made more sense |
| 269 | nextCopy := next |
| 270 | |
| 271 | // if route is part of a group, ensure only the |
| 272 | // first matching route in the group is applied |
| 273 | var groups map[string]struct{} |
| 274 | if route.Group != "" { |
| 275 | groups = req.Context().Value(routeGroupCtxKey).(map[string]struct{}) |
| 276 | |
| 277 | if _, ok := groups[route.Group]; ok { |
| 278 | // this group has already been satisfied by a |
| 279 | // matching route; skip without running matchers |
| 280 | return nextCopy.ServeHTTP(rw, req) |
| 281 | } |
| 282 | } |
| 283 | |
| 284 | // route must match at least one of the matcher sets |
| 285 | matches, err := route.MatcherSets.AnyMatchWithError(req) |
| 286 | if err != nil { |
| 287 | // allow matchers the opportunity to short circuit |
| 288 | // the request and trigger the error handling chain |
| 289 | return err |
| 290 | } |
| 291 | if !matches { |
| 292 | // call the next handler, and skip this one, |
| 293 | // since the matcher didn't match |
| 294 | return nextCopy.ServeHTTP(rw, req) |
| 295 | } |
| 296 | |
| 297 | // this matching route satisfies the group |
| 298 | if groups != nil { |
| 299 | groups[route.Group] = struct{}{} |
| 300 | } |
| 301 | |
| 302 | // make terminal routes terminate |
| 303 | if route.Terminal { |
| 304 | if _, ok := req.Context().Value(ErrorCtxKey).(error); ok { |
| 305 | nextCopy = errorEmptyHandler |
| 306 | } else { |
| 307 | nextCopy = emptyHandler |
| 308 | } |
| 309 | } |
| 310 | |
| 311 | // compile this route's handler stack |
| 312 | for _, middleware := range slices.Backward(route.middleware) { |
| 313 | nextCopy = middleware(nextCopy) |
| 314 | } |
| 315 | |
| 316 | // Apply metrics instrumentation once for the entire route, |
| 317 | // rather than wrapping each individual handler. This avoids |
| 318 | // redundant metrics collection that caused significant CPU |
| 319 | // overhead (see issue #4644). |
| 320 | if route.metrics != nil { |
| 321 | nextCopy = newMetricsInstrumentedRoute( |
| 322 | route.metricsCtx, route.handlerName, nextCopy, route.metrics, |
| 323 | ) |
| 324 | } |
| 325 | |
| 326 | return nextCopy.ServeHTTP(rw, req) |
| 327 | }) |
| 328 | } |
| 329 | } |
| 330 | |
| 331 | // wrapMiddleware wraps mh such that it can be correctly |
| 332 | // appended to a list of middleware in preparation for |
| 333 | // compiling into a handler chain. |
| 334 | func wrapMiddleware(ctx caddy.Context, mh MiddlewareHandler) Middleware { |
| 335 | return func(next Handler) Handler { |
| 336 | return HandlerFunc(func(w http.ResponseWriter, r *http.Request) error { |
| 337 | // EXPERIMENTAL: Trace each module that gets invoked |
| 338 | if server, ok := r.Context().Value(ServerCtxKey).(*Server); ok && server != nil { |
| 339 | server.logTrace(mh) |
| 340 | } |
| 341 | return mh.ServeHTTP(w, r, next) |
| 342 | }) |
| 343 | } |
| 344 | } |
| 345 | |
| 346 | // MatcherSet is a set of matchers which |
| 347 | // must all match in order for the request |
| 348 | // to be matched successfully. |
| 349 | type MatcherSet []any |
| 350 | |
| 351 | // Match returns true if the request matches all |
| 352 | // matchers in mset or if there are no matchers. |
| 353 | func (mset MatcherSet) Match(r *http.Request) bool { |
| 354 | for _, m := range mset { |
| 355 | if me, ok := m.(RequestMatcherWithError); ok { |
| 356 | match, _ := me.MatchWithError(r) |
| 357 | if !match { |
| 358 | return false |
| 359 | } |
| 360 | continue |
| 361 | } |
| 362 | if me, ok := m.(RequestMatcher); ok { |
| 363 | if !me.Match(r) { |
| 364 | return false |
| 365 | } |
| 366 | continue |
| 367 | } |
| 368 | return false |
| 369 | } |
| 370 | return true |
| 371 | } |
| 372 | |
| 373 | // MatchWithError returns true if r matches m. |
| 374 | func (mset MatcherSet) MatchWithError(r *http.Request) (bool, error) { |
| 375 | for _, m := range mset { |
| 376 | if me, ok := m.(RequestMatcherWithError); ok { |
| 377 | match, err := me.MatchWithError(r) |
| 378 | if err != nil || !match { |
| 379 | return match, err |
| 380 | } |
| 381 | continue |
| 382 | } |
| 383 | if me, ok := m.(RequestMatcher); ok { |
| 384 | if !me.Match(r) { |
| 385 | // for backwards compatibility |
| 386 | err, ok := GetVar(r.Context(), MatcherErrorVarKey).(error) |
| 387 | if ok { |
| 388 | // clear out the error from context since we've consumed it |
| 389 | SetVar(r.Context(), MatcherErrorVarKey, nil) |
| 390 | return false, err |
| 391 | } |
| 392 | return false, nil |
| 393 | } |
| 394 | continue |
| 395 | } |
| 396 | return false, fmt.Errorf("matcher is not a RequestMatcher or RequestMatcherWithError: %#v", m) |
| 397 | } |
| 398 | return true, nil |
| 399 | } |
| 400 | |
| 401 | // RawMatcherSets is a group of matcher sets |
| 402 | // in their raw, JSON form. |
| 403 | type RawMatcherSets []caddy.ModuleMap |
| 404 | |
| 405 | // MatcherSets is a group of matcher sets capable |
| 406 | // of checking whether a request matches any of |
| 407 | // the sets. |
| 408 | type MatcherSets []MatcherSet |
| 409 | |
| 410 | // AnyMatch returns true if req matches any of the |
| 411 | // matcher sets in ms or if there are no matchers, |
| 412 | // in which case the request always matches. |
| 413 | // |
| 414 | // Deprecated: Use AnyMatchWithError instead. |
| 415 | func (ms MatcherSets) AnyMatch(req *http.Request) bool { |
| 416 | for _, m := range ms { |
| 417 | match, err := m.MatchWithError(req) |
| 418 | if err != nil { |
| 419 | SetVar(req.Context(), MatcherErrorVarKey, err) |
| 420 | return false |
| 421 | } |
| 422 | if match { |
| 423 | return match |
| 424 | } |
| 425 | } |
| 426 | return len(ms) == 0 |
| 427 | } |
| 428 | |
| 429 | // AnyMatchWithError returns true if req matches any of the |
| 430 | // matcher sets in ms or if there are no matchers, in which |
| 431 | // case the request always matches. If any matcher returns |
| 432 | // an error, we cut short and return the error. |
| 433 | func (ms MatcherSets) AnyMatchWithError(req *http.Request) (bool, error) { |
| 434 | for _, m := range ms { |
| 435 | match, err := m.MatchWithError(req) |
| 436 | if err != nil || match { |
| 437 | return match, err |
| 438 | } |
| 439 | } |
| 440 | return len(ms) == 0, nil |
| 441 | } |
| 442 | |
| 443 | // FromInterface fills ms from an 'any' value obtained from LoadModule. |
| 444 | func (ms *MatcherSets) FromInterface(matcherSets any) error { |
| 445 | for _, matcherSetIfaces := range matcherSets.([]map[string]any) { |
| 446 | var matcherSet MatcherSet |
| 447 | for _, matcher := range matcherSetIfaces { |
| 448 | if m, ok := matcher.(RequestMatcherWithError); ok { |
| 449 | matcherSet = append(matcherSet, m) |
| 450 | continue |
| 451 | } |
| 452 | if m, ok := matcher.(RequestMatcher); ok { |
| 453 | matcherSet = append(matcherSet, m) |
| 454 | continue |
| 455 | } |
| 456 | return fmt.Errorf("decoded module is not a RequestMatcher or RequestMatcherWithError: %#v", matcher) |
| 457 | } |
| 458 | *ms = append(*ms, matcherSet) |
| 459 | } |
| 460 | return nil |
| 461 | } |
| 462 | |
| 463 | // TODO: Is this used? |
| 464 | func (ms MatcherSets) String() string { |
| 465 | var result strings.Builder |
| 466 | result.WriteByte('[') |
| 467 | for _, matcherSet := range ms { |
| 468 | for _, matcher := range matcherSet { |
| 469 | fmt.Fprintf(&result, " %#v", matcher) |
| 470 | } |
| 471 | } |
| 472 | result.WriteByte(']') |
| 473 | return result.String() |
| 474 | } |
| 475 | |
| 476 | var routeGroupCtxKey = caddy.CtxKey("route_group") |