Add verification of lua load balancer to health check (#2308)

internal/ingress/controller/checker.go

@@ -42,6 +42,17 @@ func (n *NGINXController) Check(_ *http.Request) error {
 		return fmt.Errorf("ingress controller is not healthy")
 	}
 
+	if n.cfg.DynamicConfigurationEnabled {
+		res, err := http.Get(fmt.Sprintf("http://0.0.0.0:%v/is-dynamic-lb-initialized", n.cfg.ListenPorts.Status))
+		if err != nil {
+			return err
+		}
+		defer res.Body.Close()
+		if res.StatusCode != 200 {
+			return fmt.Errorf("dynamic load balancer not started")
+		}
+	}
+
 	// check the nginx master process is running
 	fs, err := proc.NewFS("/proc")
 	if err != nil {

rootfs/etc/nginx/template/nginx.tmpl

@@ -487,10 +487,32 @@ http {
         set $proxy_upstream_name "-";
 
         location {{ $healthzURI }} {
+            {{ if $cfg.EnableOpentracing }}
+            opentracing off;
+            {{ end }}
             access_log off;
             return 200;
         }
 
+        location /is-dynamic-lb-initialized {
+            {{ if $cfg.EnableOpentracing }}
+            opentracing off;
+            {{ end }}
+            access_log off;
+
+            content_by_lua_block {
+                local configuration = require("configuration")
+                local backend_data = configuration.get_backends_data()
+                if not backend_data then
+                    ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
+                    return
+                end
+
+                ngx.say("OK")
+                ngx.exit(ngx.HTTP_OK)
+            }
+        }
+
         location /nginx_status {
             set $proxy_upstream_name "internal";
             {{ if $cfg.EnableOpentracing }}