| // Copyright 2019 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package middleware |
| |
| import ( |
| "fmt" |
| "net/http" |
| |
| "cloud.google.com/go/errorreporting" |
| "golang.org/x/pkgsite/internal/config" |
| "golang.org/x/pkgsite/internal/derrors" |
| ) |
| |
| // ErrorReporting returns a middleware that reports any server errors using the |
| // report func. |
| func ErrorReporting(report func(errorreporting.Entry)) Middleware { |
| return func(h http.Handler) http.Handler { |
| return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| w2 := &erResponseWriter{ResponseWriter: w} |
| h.ServeHTTP(w2, r) |
| // Don't report if the bypass header was set. |
| if w2.bypass { |
| return |
| } |
| // Don't report success or client errors. |
| if w2.status < 500 { |
| return |
| } |
| // Don't report 503s; they are a normal consequence of load shedding. |
| if w2.status == http.StatusServiceUnavailable { |
| return |
| } |
| // Don't report errors where the proxy times out; they're too common. |
| if w2.status == derrors.ToStatus(derrors.ProxyTimedOut) { |
| return |
| } |
| // Don't report on proxy internal errors; they're not actionable. |
| if w2.status == derrors.ToStatus(derrors.ProxyError) { |
| return |
| } |
| // Don't report on vulndb errors. |
| if w2.status == derrors.ToStatus(derrors.VulnDBError) { |
| return |
| } |
| report(errorreporting.Entry{ |
| Error: fmt.Errorf("handler for %q returned status code %d", r.URL.Path, w2.status), |
| Req: r, |
| }) |
| }) |
| } |
| } |
| |
| type erResponseWriter struct { |
| http.ResponseWriter |
| |
| bypass bool |
| status int |
| } |
| |
| func (rw *erResponseWriter) WriteHeader(code int) { |
| rw.status = code |
| if rw.ResponseWriter.Header().Get(config.BypassErrorReportingHeader) == "true" { |
| rw.bypass = true |
| // Don't send this header to clients. |
| rw.ResponseWriter.Header().Del(config.BypassErrorReportingHeader) |
| } |
| rw.ResponseWriter.WriteHeader(code) |
| } |