Function recordingHandler

script/api-host-gateway/gateway/main.go:131–143

recordingHandler attaches a record to the request context so the proxy can fill in the outcome, then writes exactly one line per request once the proxy is done with it.

(proxy http.Handler, rec *recorder)

// fill in the outcome, then writes exactly one line per request once the proxy
// is done with it.
func recordingHandler(proxy http.Handler, rec *recorder) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		entry := &record{
			Time:       time.Now().UTC().Format(time.RFC3339Nano),
			Method:     r.Method,
			Path:       r.URL.RequestURI(),
			Host:       r.Host,
			AuthHeader: r.Header.Get("Authorization") != "",
		}
		proxy.ServeHTTP(w, r.WithContext(context.WithValue(r.Context(), recordKey{}, entry)))
		rec.Write(entry)
	})
}

// newProxy builds the reverse proxy. The upstream URL carries the canonical
// host that requests are forwarded to and that responses are rewritten from,