feat: implement apisix healthz check (#770)

pkg/api/router/apisix_healthz.go

@@ -0,0 +1,42 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License.  You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package router
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+// MountWebhooks mounts apisix healthz route.
+func MountApisixHealthz(r *gin.Engine, state *HealthState) {
+	r.GET("/apisix/healthz", apisixHealthz(state))
+}
+
+func apisixHealthz(state *HealthState) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		state.RLock()
+		err := state.Err
+		state.RUnlock()
+
+		if err != nil {
+			c.AbortWithStatusJSON(http.StatusInternalServerError,
+				healthzResponse{Status: err.Error()})
+			return
+		}
+		c.AbortWithStatusJSON(http.StatusOK, healthzResponse{Status: "ok"})
+	}
+}

pkg/api/router/router.go

@@ -28,7 +28,6 @@ type healthzResponse struct {
 
 func mountHealthz(r *gin.Engine) {
 	r.GET("/healthz", healthz)
-	r.GET("/apisix/healthz", healthz)
 }
 
 func healthz(c *gin.Context) {

pkg/api/router/router_test.go

@@ -41,6 +41,22 @@ func TestHealthz(t *testing.T) {
 	assert.Equal(t, healthzResponse{Status: "ok"}, resp)
 }
 
+func TestApisixHealthz(t *testing.T) {
+	w := httptest.NewRecorder()
+	c, r := gin.CreateTestContext(w)
+	var state HealthState
+	MountApisixHealthz(r, &state)
+	apisixHealthz(&state)(c)
+
+	assert.Equal(t, w.Code, http.StatusOK)
+
+	var resp healthzResponse
+	dec := json.NewDecoder(w.Body)
+	assert.Nil(t, dec.Decode(&resp))
+
+	assert.Equal(t, resp, healthzResponse{Status: "ok"})
+}
+
 func TestMetrics(t *testing.T) {
 	w := httptest.NewRecorder()
 	c, r := gin.CreateTestContext(w)

pkg/api/router/types.go

@@ -0,0 +1,25 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License.  You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package router
+
+import "sync"
+
+// HealthState stores healthcheck err of APISIX
+type HealthState struct {
+	sync.RWMutex
+
+	Err error
+}

pkg/api/server.go

@@ -35,6 +35,7 @@ import (
 
 // Server represents the API Server in ingress-apisix-controller.
 type Server struct {
+	HealthState     *apirouter.HealthState
 	httpServer      *gin.Engine
 	admissionServer *http.Server
 	httpListener    net.Listener
@@ -53,9 +54,12 @@ func NewServer(cfg *config.Config) (*Server, error) {
 	apirouter.Mount(httpServer)
 
 	srv := &Server{
+		HealthState:  new(apirouter.HealthState),
 		httpServer:   httpServer,
 		httpListener: httpListener,
 	}
+	apirouter.MountApisixHealthz(httpServer, srv.HealthState)
+
 	if cfg.EnableProfiling {
 		srv.pprofMu = new(http.ServeMux)
 		srv.pprofMu.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)

pkg/ingress/controller.go

@@ -650,6 +650,10 @@ func (c *Controller) checkClusterHealth(ctx context.Context, cancelFunc context.
 		if err != nil {
 			// Finally failed health check, then give up leader.
 			log.Warnf("failed to check health for default cluster: %s, give up leader", err)
+			c.apiServer.HealthState.Lock()
+			defer c.apiServer.HealthState.Unlock()
+
+			c.apiServer.HealthState.Err = err
 			return
 		}
 		log.Debugf("success check health for default cluster")