add health check

agent/api/provider.go

@@ -1,10 +1,12 @@
 package api
 
 import (
+	"github.com/gorilla/mux"
 	"github.com/mylxsw/asteria/log"
 	"github.com/mylxsw/container"
 	"github.com/mylxsw/glacier"
 	"github.com/mylxsw/glacier/web"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 type ServiceProvider struct{}
@@ -13,6 +15,10 @@ func (s ServiceProvider) Register(app container.Container) {}
 
 func (s ServiceProvider) Boot(app glacier.Glacier) {
 	app.WebAppRouter(routers(app.Container()))
+	app.WebAppMuxRouter(func(router *mux.Router) {
+		// prometheus metrics
+		router.PathPrefix("/metrics").Handler(promhttp.Handler())
+	})
 }
 
 func routers(cc container.Container) func(router *web.Router, mw web.RequestMiddleware) {

api/provider.go

@@ -8,6 +8,7 @@ import (
 	_ "github.com/mylxsw/adanos-alert/docs"
 	"github.com/mylxsw/container"
 	"github.com/mylxsw/glacier"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	httpSwagger "github.com/swaggo/http-swagger"
 )
 
@@ -34,8 +35,20 @@ func (s ServiceProvider) Boot(app glacier.Glacier) {
 		app.WebAppMuxRouter(func(router *mux.Router) {
 			// Swagger doc
 			router.PathPrefix("/swagger/").Handler(httpSwagger.WrapHandler).Name("swagger")
+			// prometheus metrics
+			router.PathPrefix("/metrics").Handler(promhttp.Handler())
+			// health check
+			router.PathPrefix("/health").Handler(HealthCheck{})
 			// Dashboard
 			router.PathPrefix("/").Handler(http.StripPrefix("/", http.FileServer(FS(conf.UseLocalDashboard)))).Name("assets")
 		})
 	})
 }
+
+type HealthCheck struct{}
+
+func (h HealthCheck) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
+	writer.Header().Add("Content-Type", "application/json")
+	writer.WriteHeader(http.StatusOK)
+	_, _ = writer.Write([]byte(`{"status": "UP"}`))
+}

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/buger/jsonparser v1.0.0
 	github.com/cpuguy83/go-md2man/v2 v2.0.0 // indirect
 	github.com/go-chi/chi v3.3.2+incompatible // indirect
-	github.com/golang/protobuf v1.4.0
+	github.com/golang/protobuf v1.4.2
 	github.com/golang/snappy v0.0.1 // indirect
 	github.com/gorilla/mux v1.7.4
 	github.com/gorilla/websocket v1.4.2 // indirect
@@ -23,6 +23,7 @@ require (
 	github.com/mylxsw/go-toolkit v0.0.0-20191208081907-50a06279f988
 	github.com/mylxsw/graceful v0.0.0-20200605063420-3c53968cf134
 	github.com/pkg/errors v0.9.1
+	github.com/prometheus/client_golang v1.7.1
 	github.com/robfig/cron/v3 v3.0.1 // indirect
 	github.com/satori/go.uuid v1.2.0
 	github.com/siddontang/go v0.0.0-20170517070808-cb568a3e5cc0
@@ -41,6 +42,6 @@ require (
 	golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e // indirect
 	golang.org/x/tools v0.0.0-20191007185444-6536af71d98a // indirect
 	google.golang.org/grpc v1.28.1
-	google.golang.org/protobuf v1.21.0
+	google.golang.org/protobuf v1.23.0
 	gopkg.in/yaml.v2 v2.3.0 // indirect
 )