Add /healthz endpoint for basic readiness/liveness checks

.gitignore

@@ -1,2 +1,3 @@
 go-sample-app
+hello_server
 

go.mod

@@ -3,6 +3,6 @@ module github.com/harness/go-sample-app
 go 1.15
 
 require (
-	github.com/gorilla/context v1.1.1
+	github.com/gorilla/context v1.1.1 // indirect
 	github.com/gorilla/mux v1.6.2
 )

go.sum

@@ -1,4 +1,4 @@
+github.com/gorilla/context v1.1.1 h1:AWwleXJkX/nhcU9bZSnZoi3h/qGYqQAGhq6zZe/aQW8=
 github.com/gorilla/context v1.1.1/go.mod h1:kBGZzfjB9CEq2AlWe17Uuf7NDRt0dE0s8S51q0aT7Yg=
 github.com/gorilla/mux v1.6.2 h1:Pgr17XVTNXAk3q/r4CpKzC5xBM/qW1uVLV+IhRZpIIk=
 github.com/gorilla/mux v1.6.2/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
-

hello_server.go

@@ -19,6 +19,12 @@ func handler(w http.ResponseWriter, r *http.Request) {
 	w.Write([]byte(CreateGreeting(name)))
 }
 
+func healthzHandler(w http.ResponseWriter, r *http.Request) {
+	log.Printf("Health check request received")
+	w.WriteHeader(http.StatusOK)
+	w.Write([]byte("OK\n"))
+}
+
 func CreateGreeting(name string) string {
 	if name == "" {
 		name = "Guest"
@@ -31,6 +37,7 @@ func main() {
 	r := mux.NewRouter()
 
 	r.HandleFunc("/", handler)
+	r.HandleFunc("/healthz", healthzHandler)
 
 	srv := &http.Server{
 		Handler:      r,

hello_server_test.go

@@ -1,6 +1,7 @@
 package main
 import (
-
+    "net/http"
+    "net/http/httptest"
     "time"
     "testing"
 )
@@ -36,6 +37,31 @@ func TestGreetingDefault(t *testing.T) {
 		t.Errorf("Greeting was incorrect, got: %s, want: %s.", greeting, "Hello, Guest\n")
 	}
 }
+
+func TestHealthzEndpoint(t *testing.T) {
+	req, err := http.NewRequest("GET", "/healthz", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	rr := httptest.NewRecorder()
+	handler := http.HandlerFunc(healthzHandler)
+
+	handler.ServeHTTP(rr, req)
+
+	// Check the status code is what we expect
+	if status := rr.Code; status != http.StatusOK {
+		t.Errorf("handler returned wrong status code: got %v want %v",
+			status, http.StatusOK)
+	}
+
+	// Check the response body is what we expect
+	expected := "OK\n"
+	if rr.Body.String() != expected {
+		t.Errorf("handler returned unexpected body: got %v want %v",
+			rr.Body.String(), expected)
+	}
+}