Function TestHTTPInstrumentationMetrics

server/server_test.go:278–486

(t *testing.T)

}

func TestHTTPInstrumentationMetrics(t *testing.T) {
	reg := prometheus.NewRegistry()
	prometheus.DefaultRegisterer = reg
	prometheus.DefaultGatherer = reg

	var cfg Config
	cfg.PerTenantInstrumentation = func(_ context.Context) *middleware.PerTenantConfig {
		return &middleware.PerTenantConfig{
			TenantID:     "test",
			TotalCounter: true,
		}
	}
	cfg.RegisterFlags(flag.NewFlagSet("", flag.ExitOnError))
	setAutoAssignedPorts(DefaultNetwork, &cfg)

	server, err := New(cfg)
	require.NoError(t, err)

	server.HTTP.HandleFunc("/succeed", func(w http.ResponseWriter, _ *http.Request) {
		_, _ = w.Write([]byte("OK"))
	})
	server.HTTP.HandleFunc("/error500", func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(500)
	})
	server.HTTP.HandleFunc("/sleep10", func(_ http.ResponseWriter, r *http.Request) {
		_, _ = io.Copy(io.Discard, r.Body) // Consume body, otherwise it's not counted.
		_ = cancelableSleep(r.Context(), time.Second*10)
	})

	go func() {
		require.NoError(t, server.Run())
	}()

	callThenCancel := func(f func(ctx context.Context) error) error {
		ctx, cancel := context.WithCancel(context.Background())
		errChan := make(chan error, 1)
		go func() {
			errChan <- f(ctx)
		}()
		time.Sleep(50 * time.Millisecond) // allow the call to reach the handler
		cancel()
		return <-errChan
	}

	// Now test the HTTP versions of the functions
	{
		req, err := http.NewRequest("GET", httpTarget(server, "/succeed"), nil)
		require.NoError(t, err)
		resp, err := http.DefaultClient.Do(req)
		require.NoError(t, err)
		body, err := io.ReadAll(resp.Body)
		require.NoError(t, err)
		require.Equal(t, "OK", string(body))
	}
	{
		req, err := http.NewRequest("GET", httpTarget(server, "/error500"), nil)
		require.NoError(t, err)
		_, err = http.DefaultClient.Do(req)