Merge pull request #1156 from prymitive/health

feat(backend): add /health endpoint for healthcheck probes

README.md

@@ -194,6 +194,11 @@ apply as with `make run`. Example:
 
     make PORT=5000 ALERTMANAGER_URI=https://alertmanager.example.com run-docker
 
+### Health checks
+
+`/health` endpoint can be used for health check probes, it always responds with
+`200 OK` code and `Pong` response body.
+
 ## Configuration
 
 Please see [CONFIGURATION](/docs/CONFIGURATION.md) for full list of available

cmd/karma/main.go

@@ -98,6 +98,7 @@ func setupRouter(router *gin.Engine) {
 	}))
 
 	router.GET(getViewURL("/"), index)
+	router.GET(getViewURL("/health"), pong)
 	router.GET(getViewURL("/alerts.json"), alerts)
 	router.GET(getViewURL("/autocomplete.json"), autocomplete)
 	router.GET(getViewURL("/labelNames.json"), knownLabelNames)

cmd/karma/views.go

@@ -33,6 +33,10 @@ func noCache(c *gin.Context) {
 	c.Header("Cache-Control", "no-cache, no-store, must-revalidate")
 }
 
+func pong(c *gin.Context) {
+	c.String(200, "Pong")
+}
+
 func compressResponse(data []byte) ([]byte, error) {
 	var b bytes.Buffer
 	gz, err := gzip.NewWriterLevel(&b, 3)

cmd/karma/views_test.go

@@ -49,6 +49,30 @@ func ginTestEngine() *gin.Engine {
 	return r
 }
 
+func TestHealth(t *testing.T) {
+	mockConfig()
+	r := ginTestEngine()
+	req := httptest.NewRequest("GET", "/health", nil)
+	resp := httptest.NewRecorder()
+	r.ServeHTTP(resp, req)
+	if resp.Code != http.StatusOK {
+		t.Errorf("GET /health returned status %d", resp.Code)
+	}
+}
+
+func TestHealthPrefix(t *testing.T) {
+	os.Setenv("LISTEN_PREFIX", "/prefix")
+	defer os.Unsetenv("LISTEN_PREFIX")
+	mockConfig()
+	r := ginTestEngine()
+	req := httptest.NewRequest("GET", "/prefix/health", nil)
+	resp := httptest.NewRecorder()
+	r.ServeHTTP(resp, req)
+	if resp.Code != http.StatusOK {
+		t.Errorf("GET /prefix/health returned status %d", resp.Code)
+	}
+}
+
 func TestIndex(t *testing.T) {
 	mockConfig()
 	r := ginTestEngine()