diff --git a/modules/caddyhttp/caddyhttp.go b/modules/caddyhttp/caddyhttp.go index fda7a929..a7ac8890 100644 --- a/modules/caddyhttp/caddyhttp.go +++ b/modules/caddyhttp/caddyhttp.go @@ -92,6 +92,45 @@ var errorEmptyHandler Handler = HandlerFunc(func(w http.ResponseWriter, r *http. return nil }) +// ResponseHandler pairs a response matcher with custom handling +// logic. Either the status code can be changed to something else +// while using the original response body, or, if a status code +// is not set, it can execute a custom route list; this is useful +// for executing handler routes based on the properties of an HTTP +// response that has not been written out to the client yet. +// +// To use this type, provision it at module load time, then when +// ready to use, match the response against its matcher; if it +// matches (or doesn't have a matcher), change the status code on +// the response if configured; otherwise invoke the routes by +// calling `rh.Routes.Compile(next).ServeHTTP(rw, req)` (or similar). +type ResponseHandler struct { + // The response matcher for this handler. If empty/nil, + // it always matches. + Match *ResponseMatcher `json:"match,omitempty"` + + // To write the original response body but with a different + // status code, set this field to the desired status code. + // If set, this takes priority over routes. + StatusCode WeakString `json:"status_code,omitempty"` + + // The list of HTTP routes to execute if no status code is + // specified. If evaluated, the original response body + // will not be written. + Routes RouteList `json:"routes,omitempty"` +} + +// Provision sets up the routse in rh. +func (rh *ResponseHandler) Provision(ctx caddy.Context) error { + if rh.Routes != nil { + err := rh.Routes.Provision(ctx) + if err != nil { + return err + } + } + return nil +} + // WeakString is a type that unmarshals any JSON value // as a string literal, with the following exceptions: // diff --git a/modules/caddyhttp/reverseproxy/reverseproxy.go b/modules/caddyhttp/reverseproxy/reverseproxy.go index 06802a01..79713484 100644 --- a/modules/caddyhttp/reverseproxy/reverseproxy.go +++ b/modules/caddyhttp/reverseproxy/reverseproxy.go @@ -24,6 +24,7 @@ import ( "net" "net/http" "regexp" + "strconv" "strings" "sync" "time" @@ -531,15 +532,32 @@ func (h *Handler) reverseProxy(rw http.ResponseWriter, req *http.Request, di Dia } } + // see if any response handler is configured for this response from the backend for i, rh := range h.HandleResponse { - if len(rh.Routes) == 0 { - continue - } if rh.Match != nil && !rh.Match.Match(res.StatusCode, res.Header) { continue } - res.Body.Close() + repl := req.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer) + + // if configured to only change the status code, do that then continue regular proxy response + if statusCodeStr := rh.StatusCode.String(); statusCodeStr != "" { + statusCode, err := strconv.Atoi(repl.ReplaceAll(statusCodeStr, "")) + if err != nil { + return caddyhttp.Error(http.StatusInternalServerError, err) + } + if statusCode != 0 { + res.StatusCode = statusCode + } + break + } + + // otherwise, if there are any routes configured, execute those as the + // actual response instead of what we got from the proxy backend + if len(rh.Routes) == 0 { + continue + } + res.Body.Close() repl.Set("http.reverse_proxy.status_code", res.StatusCode) repl.Set("http.reverse_proxy.status_text", res.Status) h.logger.Debug("handling response", zap.Int("handler", i)) diff --git a/modules/caddyhttp/subroute.go b/modules/caddyhttp/subroute.go index b1700f5b..2e80d88d 100644 --- a/modules/caddyhttp/subroute.go +++ b/modules/caddyhttp/subroute.go @@ -80,36 +80,6 @@ func (sr *Subroute) ServeHTTP(w http.ResponseWriter, r *http.Request, next Handl return err } -// ResponseHandler pairs a response matcher with a route list. -// It is useful for executing handler routes based on the -// properties of an HTTP response that has not been written -// out to the client yet. -// -// To use this type, provision it at module load time, then -// when ready to use, match the response against its matcher; -// if it matches (or doesn't have a matcher), invoke the routes -// by calling `rh.Routes.Compile(next).ServeHTTP(rw, req)` (or -// similar). -type ResponseHandler struct { - // The response matcher for this handler. If empty/nil, - // it always matches. - Match *ResponseMatcher `json:"match,omitempty"` - - // The list of HTTP routes to execute. - Routes RouteList `json:"routes,omitempty"` -} - -// Provision sets up the routse in rh. -func (rh *ResponseHandler) Provision(ctx caddy.Context) error { - if rh.Routes != nil { - err := rh.Routes.Provision(ctx) - if err != nil { - return err - } - } - return nil -} - // Interface guards var ( _ caddy.Provisioner = (*Subroute)(nil)