package recovery import ( "context" "net/http" "runtime" "github.com/traefik/traefik/v2/pkg/log" "github.com/traefik/traefik/v2/pkg/middlewares" ) const ( typeName = "Recovery" ) type recovery struct { next http.Handler name string } // New creates recovery middleware. func New(ctx context.Context, next http.Handler, name string) (http.Handler, error) { log.FromContext(middlewares.GetLoggerCtx(ctx, name, typeName)).Debug("Creating middleware") return &recovery{ next: next, name: name, }, nil } func (re *recovery) ServeHTTP(rw http.ResponseWriter, req *http.Request) { defer recoverFunc(middlewares.GetLoggerCtx(req.Context(), re.name, typeName), rw, req) re.next.ServeHTTP(rw, req) } func recoverFunc(ctx context.Context, rw http.ResponseWriter, r *http.Request) { if err := recover(); err != nil { if !shouldLogPanic(err) { log.FromContext(ctx).Debugf("Request has been aborted [%s - %s]: %v", r.RemoteAddr, r.URL, err) return } log.FromContext(ctx).Errorf("Recovered from panic in HTTP handler [%s - %s]: %+v", r.RemoteAddr, r.URL, err) const size = 64 << 10 buf := make([]byte, size) buf = buf[:runtime.Stack(buf, false)] log.FromContext(ctx).Errorf("Stack: %s", buf) http.Error(rw, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError) } } // https://github.com/golang/go/blob/a0d6420d8be2ae7164797051ec74fa2a2df466a1/src/net/http/server.go#L1761-L1775 // https://github.com/golang/go/blob/c33153f7b416c03983324b3e8f869ce1116d84bc/src/net/http/httputil/reverseproxy.go#L284 func shouldLogPanic(panicValue interface{}) bool { return panicValue != nil && panicValue != http.ErrAbortHandler }