Function Recoverer

middleware/recoverer.go:22–49

Recoverer is a middleware that recovers from panics, logs the panic (and a backtrace), and returns a HTTP 500 (Internal Server Error) status if possible. Recoverer prints a request ID if one is provided. Alternatively, look at https://github.com/go-chi/httplog middleware pkgs.

(next http.Handler)

//
// Alternatively, look at https://github.com/go-chi/httplog middleware pkgs.
func Recoverer(next http.Handler) http.Handler {
	fn := func(w http.ResponseWriter, r *http.Request) {
		defer func() {
			if rvr := recover(); rvr != nil {
				if rvr == http.ErrAbortHandler {
					// we don't recover http.ErrAbortHandler so the response
					// to the client is aborted, this should not be logged
					panic(rvr)
				}

				logEntry := GetLogEntry(r)
				if logEntry != nil {
					logEntry.Panic(rvr, debug.Stack())
				} else {
					PrintPrettyStack(rvr)
				}

				if r.Header.Get("Connection") != "Upgrade" {
					w.WriteHeader(http.StatusInternalServerError)
				}
			}
		}()

		next.ServeHTTP(w, r)
	}

	return http.HandlerFunc(fn)
}

// for ability to test the PrintPrettyStack function
var recovererErrorWriter io.Writer = os.Stderr