Function Logger

coderd/httpmw/loggermw/logger.go:71–129

(log slog.Logger, hostResolver func(*http.Request) string)

}

func Logger(log slog.Logger, hostResolver func(*http.Request) string) func(next http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
			start := time.Now()

			sw, ok := rw.(*tracing.StatusWriter)
			if !ok {
				panic(fmt.Sprintf("ResponseWriter not a *tracing.StatusWriter; got %T", rw))
			}

			host := r.Host
			if hostResolver != nil {
				host = hostResolver(r)
			}

			httplog := log.With(
				slog.F("user_agent", r.Header.Get("User-Agent")),
				slog.F("host", host),
				slog.F("received_host", r.Host),
				slog.F("path", r.URL.Path),
				slog.F("proto", r.Proto),
				slog.F("remote_addr", r.RemoteAddr),
				// Include the start timestamp in the log so that we have the
				// source of truth. There is at least a theoretical chance that
				// there can be a delay between `next.ServeHTTP` ending and us
				// actually logging the request. This can also be useful when
				// filtering logs that started at a certain time (compared to
				// trying to compute the value).
				slog.F("start", start),
			)

			// Add safe query parameters to the log
			if queryFields := safeQueryParams(r.URL.Query()); len(queryFields) > 0 {
				httplog = httplog.With(queryFields...)
			}

			logContext := NewRequestLogger(httplog, r.Method, start)

			ctx := WithRequestLogger(r.Context(), logContext)

			next.ServeHTTP(sw, r.WithContext(ctx))

			// Don't log successful health check requests.
			if r.URL.Path == "/api/v2" && sw.Status == http.StatusOK {
				return
			}

			// For status codes 500 and higher we
			// want to log the response body.
			if sw.Status >= http.StatusInternalServerError {
				logContext.WithFields(
					slog.F("response_body", string(sw.ResponseBody())),
				)
			}

			logContext.WriteLog(r.Context(), sw.Status)
		})
	}