Improve health check API

README.md

@@ -90,7 +90,7 @@ git clone https://github.com/cloud-barista/cm-cicada.git
 Check if CM-Cicada is running
 
 ```bash
-curl http://127.0.0.1:8083/cicada/health
+curl http://127.0.0.1:8083/cicada/readyz
 
 # Output if it's running successfully
 # {"message":"CM-Cicada API server is running"}

cmd/cm-cicada/main.go

@@ -5,13 +5,15 @@ import (
 	"github.com/cloud-barista/cm-cicada/db"
 	"github.com/cloud-barista/cm-cicada/lib/airflow"
 	"github.com/cloud-barista/cm-cicada/lib/config"
+	"github.com/cloud-barista/cm-cicada/pkg/api/rest/controller"
 	"github.com/cloud-barista/cm-cicada/pkg/api/rest/server"
 	"github.com/jollaman999/utils/logger"
 	"github.com/jollaman999/utils/syscheck"
 	"log"
 	"os"
 	"os/signal"
 	"strings"
+	"sync"
 	"syscall"
 )
 
@@ -31,14 +33,29 @@ func init() {
 		log.Panicln(err)
 	}
 
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer func() {
+			wg.Done()
+		}()
+		controller.OkMessage.Message = "API server is not ready"
+		server.Init()
+	}()
+
+	controller.OkMessage.Message = "Database is not ready"
 	err = db.Open()
 	if err != nil {
 		logger.Panicln(logger.ERROR, true, err.Error())
 	}
 
+	controller.OkMessage.Message = "Airflow connection is not ready"
 	airflow.Init()
 
-	server.Init()
+	controller.OkMessage.Message = "CM-Cicada API server is ready"
+	controller.IsReady = true
+
+	wg.Wait()
 }
 
 func end() {

pkg/api/rest/controller/health.go

@@ -10,18 +10,25 @@ type SimpleMsg struct {
 	Message string `json:"message"`
 }
 
-// GetHealth func is for checking Cicada server health.
-// @Summary Check Cicada is alive
-// @Description Check Cicada is alive
+var OkMessage = SimpleMsg{}
+var IsReady = false
+
+// CheckReady func is for checking Cicada server health.
+// @Summary Check Ready
+// @Description Check Cicada is ready
 // @Tags [Admin] System management
-// @Accept  json
-// @Produce  json
-// @Success		200 {object}	SimpleMsg	"Successfully get heath state."
-// @Failure		500	{object}	common.ErrorResponse	"Failed to check health."
+// @Accept		json
+// @Produce		json
+// @Success		200 {object}	SimpleMsg				"Successfully get ready state."
+// @Failure		500	{object}	common.ErrorResponse	"Failed to check ready state."
 //
-// @Router /cicada/health [get]
-func GetHealth(c echo.Context) error {
-	okMessage := SimpleMsg{}
-	okMessage.Message = "CM-Cicada API server is running"
-	return c.JSONPretty(http.StatusOK, &okMessage, " ")
+// @Router /cicada/readyz [get]
+func CheckReady(c echo.Context) error {
+	status := http.StatusOK
+
+	if !IsReady {
+		status = http.StatusServiceUnavailable
+	}
+
+	return c.JSONPretty(status, &OkMessage, " ")
 }

pkg/api/rest/docs/docs.go

@@ -15,9 +15,9 @@ const docTemplate = `{
     "host": "{{.Host}}",
     "basePath": "{{.BasePath}}",
     "paths": {
-        "/cicada/health": {
+        "/cicada/readyz": {
             "get": {
-                "description": "Check Cicada is alive",
+                "description": "Check Cicada is ready",
                 "consumes": [
                     "application/json"
                 ],
@@ -27,16 +27,16 @@ const docTemplate = `{
                 "tags": [
                     "[Admin] System management"
                 ],
-                "summary": "Check Cicada is alive",
+                "summary": "Check Ready",
                 "responses": {
                     "200": {
-                        "description": "Successfully get heath state.",
+                        "description": "Successfully get ready state.",
                         "schema": {
                             "$ref": "#/definitions/pkg_api_rest_controller.SimpleMsg"
                         }
                     },
                     "500": {
-                        "description": "Failed to check health.",
+                        "description": "Failed to check ready state.",
                         "schema": {
                             "$ref": "#/definitions/github_com_cloud-barista_cm-cicada_pkg_api_rest_common.ErrorResponse"
                         }

pkg/api/rest/docs/swagger.json

@@ -4,9 +4,9 @@
         "contact": {}
     },
     "paths": {
-        "/cicada/health": {
+        "/cicada/readyz": {
             "get": {
-                "description": "Check Cicada is alive",
+                "description": "Check Cicada is ready",
                 "consumes": [
                     "application/json"
                 ],
@@ -16,16 +16,16 @@
                 "tags": [
                     "[Admin] System management"
                 ],
-                "summary": "Check Cicada is alive",
+                "summary": "Check Ready",
                 "responses": {
                     "200": {
-                        "description": "Successfully get heath state.",
+                        "description": "Successfully get ready state.",
                         "schema": {
                             "$ref": "#/definitions/pkg_api_rest_controller.SimpleMsg"
                         }
                     },
                     "500": {
-                        "description": "Failed to check health.",
+                        "description": "Failed to check ready state.",
                         "schema": {
                             "$ref": "#/definitions/github_com_cloud-barista_cm-cicada_pkg_api_rest_common.ErrorResponse"
                         }

pkg/api/rest/docs/swagger.yaml

@@ -182,23 +182,23 @@ definitions:
 info:
   contact: {}
 paths:
-  /cicada/health:
+  /cicada/readyz:
     get:
       consumes:
       - application/json
-      description: Check Cicada is alive
+      description: Check Cicada is ready
       produces:
       - application/json
       responses:
         "200":
-          description: Successfully get heath state.
+          description: Successfully get ready state.
           schema:
             $ref: '#/definitions/pkg_api_rest_controller.SimpleMsg'
         "500":
-          description: Failed to check health.
+          description: Failed to check ready state.
           schema:
             $ref: '#/definitions/github_com_cloud-barista_cm-cicada_pkg_api_rest_common.ErrorResponse'
-      summary: Check Cicada is alive
+      summary: Check Ready
       tags:
       - '[Admin] System management'
   /task_component:

pkg/api/rest/route/utility.go

@@ -9,5 +9,5 @@ import (
 )
 
 func RegisterUtility(e *echo.Echo) {
-	e.GET("/"+strings.ToLower(common.ShortModuleName)+"/health", controller.GetHealth)
+	e.GET("/"+strings.ToLower(common.ShortModuleName)+"/readyz", controller.CheckReady)
 }