Fast and extensible multi-platform HTTP/1-2-3 web server with automatic HTTPS
Mirrored from https://github.com/Slazee/caddy.git
Synced Nov 14, 05:15 UTC
httpserver: Add experimental H2C support (#3289)
* reverse_proxy: Initial attempt at H2C transport/client support (#3218) I have not tested this yet * Experimentally enabling H2C server support (closes #3227) See also #3218 I have not tested this * reverseproxy: Clean up H2C transport a bit * caddyhttp: Update godoc for h2c server; clarify experimental status * caddyhttp: Fix trailers when recording responses (fixes #3236) * caddyhttp: Tweak h2c config settings and docs
Matt Holt committed
May 5, 2020 at 12:33 UTC
41c7bd27b495ab9b5edca7afb0cf99d5e1b52944
4 files changed
+63
-1
modules/caddyhttp/app.go
+10
@@ -27,6 +27,8 @@ import (
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"github.com/caddyserver/caddy/v2/modules/caddytls"
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"github.com/lucas-clemente/quic-go/http3"
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"go.uber.org/zap"
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+ "golang.org/x/net/http2"
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+ "golang.org/x/net/http2/h2c"
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)
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func init() {
@@ -282,6 +284,14 @@ func (app *App) Start() error {
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Handler: srv,
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}
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+ // enable h2c if configured
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+ if srv.AllowH2C {
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+ h2server := &http2.Server{
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+ IdleTimeout: time.Duration(srv.IdleTimeout),
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+ }
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+ s.Handler = h2c.NewHandler(srv, h2server)
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+ }
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+
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for _, lnAddr := range srv.Listen {
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listenAddr, err := caddy.ParseNetworkAddress(lnAddr)
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if err != nil {
modules/caddyhttp/reverseproxy/caddyfile.go
+7
@@ -584,6 +584,7 @@ func (h *Handler) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
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// tls_trusted_ca_certs <cert_files...>
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// keepalive [off|<duration>]
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// keepalive_idle_conns <max_count>
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+// versions <versions...>
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// }
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//
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func (h *HTTPTransport) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
@@ -701,6 +702,12 @@ func (h *HTTPTransport) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
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h.KeepAlive.MaxIdleConns = num
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h.KeepAlive.MaxIdleConnsPerHost = num
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+ case "versions":
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+ h.Versions = d.RemainingArgs()
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+ if len(h.Versions) == 0 {
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+ return d.ArgErr()
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+ }
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+
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default:
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return d.Errf("unrecognized subdirective %s", d.Val())
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}
modules/caddyhttp/reverseproxy/httptransport.go
+35
-1
@@ -82,11 +82,16 @@ type HTTPTransport struct {
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// The size of the read buffer in bytes.
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ReadBufferSize int `json:"read_buffer_size,omitempty"`
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- // The versions of HTTP to support. Default: ["1.1", "2"]
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+ // The versions of HTTP to support. As a special case, "h2c"
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+ // can be specified to use H2C (HTTP/2 over Cleartext) to the
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+ // upstream (this feature is experimental and subject to
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+ // change or removal). Default: ["1.1", "2"]
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Versions []string `json:"versions,omitempty"`
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// The pre-configured underlying HTTP transport.
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Transport *http.Transport `json:"-"`
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+
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+ h2cTransport *http2.Transport
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}
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// CaddyModule returns the Caddy module information.
@@ -110,6 +115,28 @@ func (h *HTTPTransport) Provision(ctx caddy.Context) error {
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}
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h.Transport = rt
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+ // if h2c is enabled, configure its transport (std lib http.Transport
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+ // does not "HTTP/2 over cleartext TCP")
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+ if sliceContains(h.Versions, "h2c") {
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+ // crafting our own http2.Transport doesn't allow us to utilize
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+ // most of the customizations/preferences on the http.Transport,
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+ // because, for some reason, only http2.ConfigureTransport()
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+ // is allowed to set the unexported field that refers to a base
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+ // http.Transport config; oh well
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+ h2t := &http2.Transport{
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+ // kind of a hack, but for plaintext/H2C requests, pretend to dial TLS
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+ DialTLS: func(network, addr string, _ *tls.Config) (net.Conn, error) {
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+ // TODO: no context, thus potentially wrong dial info
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+ return net.Dial(network, addr)
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+ },
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+ AllowHTTP: true,
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+ }
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+ if h.Compression != nil {
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+ h2t.DisableCompression = !*h.Compression
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+ }
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+ h.h2cTransport = h2t
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+ }
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+
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return nil
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}
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@@ -182,6 +209,13 @@ func (h *HTTPTransport) NewTransport(_ caddy.Context) (*http.Transport, error) {
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// RoundTrip implements http.RoundTripper.
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func (h *HTTPTransport) RoundTrip(req *http.Request) (*http.Response, error) {
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h.SetScheme(req)
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+
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+ // if H2C ("HTTP/2 over cleartext") is enabled and the upstream request is
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+ // HTTP/2 without TLS, use the alternate H2C-capable transport instead
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+ if req.ProtoMajor == 2 && req.URL.Scheme == "http" && h.h2cTransport != nil {
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+ return h.h2cTransport.RoundTrip(req)
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+ }
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+
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return h.Transport.RoundTrip(req)
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}
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modules/caddyhttp/server.go
+11
@@ -111,6 +111,17 @@ type Server struct {
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// This field is not subject to compatibility promises.
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ExperimentalHTTP3 bool `json:"experimental_http3,omitempty"`
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+ // Enables H2C ("Cleartext HTTP/2" or "H2 over TCP") support,
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+ // which will serve HTTP/2 over plaintext TCP connections if
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+ // a client support it. Because this is not implemented by the
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+ // Go standard library, using H2C is incompatible with most
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+ // of the other options for this server. Do not enable this
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+ // only to achieve maximum client compatibility. In practice,
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+ // very few clients implement H2C, and even fewer require it.
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+ // This setting applies only to unencrypted HTTP listeners.
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+ // ⚠️ Experimental feature; subject to change or removal.
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+ AllowH2C bool `json:"allow_h2c,omitempty"`
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+
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primaryHandlerChain Handler
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errorHandlerChain Handler
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listenerWrappers []caddy.ListenerWrapper