chore: add client_ip, user_agent and response_size_bytes to slow client log

Author: mtojek

intercept/eventstream/eventstream.go

@@ -145,7 +145,13 @@ func (s *EventStream) Start(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 		if d := s.clk.Since(flushStart); d > SlowFlushThreshold {
-			s.logger.Warn(ctx, "slow client detected", slog.F("flush_duration", d))
+			clientIP, _, _ := net.SplitHostPort(r.RemoteAddr)
+			s.logger.Warn(ctx, "slow client detected",
+				slog.F("flush_duration", d),
+				slog.F("client_ip", clientIP),
+				slog.F("user_agent", r.Header.Get("User-Agent")),
+				slog.F("response_size_bytes", len(ev)),
+			)
 		}
 
 		// Reset the timer once we've flushed some data to the stream, since it's already fresh.

intercept/eventstream/eventstream_test.go

@@ -56,6 +56,8 @@ func TestEventStream_LogsWarning_WhenFlushIsSlow(t *testing.T) {
 
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, "/", nil)
 	require.NoError(t, err)
+	req.RemoteAddr = "192.0.2.1:12345"
+	req.Header.Set("User-Agent", "test-agent/1.0")
 
 	done := make(chan struct{})
 	go func() {
@@ -69,6 +71,9 @@ func TestEventStream_LogsWarning_WhenFlushIsSlow(t *testing.T) {
 	<-done
 
 	require.Contains(t, buf.String(), "slow client detected")
+	require.Contains(t, buf.String(), "192.0.2.1")
+	require.Contains(t, buf.String(), "test-agent/1.0")
+	require.Contains(t, buf.String(), "response_size_bytes=13")
 }
 
 func TestEventStream_NoWarning_WhenFlushIsFast(t *testing.T) {