Function TestFeaturesAPI

cmd/prometheus/features_test.go:35–125

(t *testing.T)

var updateFeatures = flag.Bool("update-features", false, "update features.json golden file")

func TestFeaturesAPI(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}
	t.Parallel()

	tmpDir := t.TempDir()
	configFile := filepath.Join(tmpDir, "prometheus.yml")
	require.NoError(t, os.WriteFile(configFile, []byte{}, 0o644))

	port := testutil.RandomUnprivilegedPort(t)
	prom := prometheusCommandWithLogging(
		t,
		configFile,
		port,
		fmt.Sprintf("--storage.tsdb.path=%s", tmpDir),
	)
	require.NoError(t, prom.Start())

	baseURL := fmt.Sprintf("http://127.0.0.1:%d", port)

	// Wait for Prometheus to be ready.
	require.Eventually(t, func() bool {
		resp, err := http.Get(baseURL + "/-/ready")
		if err != nil {
			return false
		}
		defer resp.Body.Close()
		return resp.StatusCode == http.StatusOK
	}, 10*time.Second, 100*time.Millisecond, "Prometheus didn't become ready in time")

	// Fetch features from the API.
	resp, err := http.Get(baseURL + "/api/v1/features")
	require.NoError(t, err)
	defer resp.Body.Close()
	require.Equal(t, http.StatusOK, resp.StatusCode)

	body, err := io.ReadAll(resp.Body)
	require.NoError(t, err)

	// Parse API response.
	var apiResponse struct {
		Status string                     `json:"status"`
		Data   map[string]map[string]bool `json:"data"`
	}
	require.NoError(t, json.Unmarshal(body, &apiResponse))
	require.Equal(t, "success", apiResponse.Status)

	goldenPath := filepath.Join("testdata", "features.json")

	// If update flag is set, write the current features to the golden file.
	if *updateFeatures {
		var buf bytes.Buffer
		encoder := json.NewEncoder(&buf)
		encoder.SetEscapeHTML(false)
		encoder.SetIndent("", "  ")
		require.NoError(t, encoder.Encode(apiResponse.Data))
		// Ensure testdata directory exists.