add helm chart with readiness endpoint

main.go

@@ -3,7 +3,6 @@ package main
 import (
 	"database/sql"
 	"fmt"
-	"html/template"
 	"log"
 	"net/http"
 	"os"
@@ -20,6 +19,28 @@ func dbConnection() (*sql.DB, error) {
 	return sql.Open("postgres", connStr)
 }
 
+// livenessHandler is used by Kubernetes to check if the app is alive.
+func livenessHandler(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(http.StatusOK)
+	fmt.Fprintf(w, "OK")
+}
+
+// readinessHandler is used by Kubernetes to check if the app is ready to serve traffic.
+func readinessHandler(w http.ResponseWriter, r *http.Request) {
+	// Check if the database connection is alive
+	err := db.Ping()
+	if err != nil {
+		log.Printf("Readiness probe failed: Database connection error: %v", err)
+		w.WriteHeader(http.StatusServiceUnavailable)
+		fmt.Fprintf(w, "NOT READY")
+		return
+	}
+
+	// If the database is reachable, return 200 OK
+	w.WriteHeader(http.StatusOK)
+	fmt.Fprintf(w, "OK")
+}
+
 // indexHandler serves the HTML form for the query.
 func indexHandler(w http.ResponseWriter, r *http.Request) {
 	tmpl := `
@@ -70,8 +91,7 @@ func indexHandler(w http.ResponseWriter, r *http.Request) {
 	</body>
 	</html>
 	`
-	t := template.Must(template.New("form").Parse(tmpl))
-	t.Execute(w, nil)
+	fmt.Fprintf(w, tmpl)
 }
 
 // selectHandler handles HTTP requests and executes a SQL query.
@@ -122,6 +142,12 @@ func main() {
 	// Define the handler for the `/query` route (executes SQL query)
 	http.HandleFunc("/query", selectHandler)
 
+	// Define the handler for the `/liveness` probe
+	http.HandleFunc("/liveness", livenessHandler)
+
+	// Define the handler for the `/readiness` probe
+	http.HandleFunc("/readiness", readinessHandler)
+
 	// Start the HTTP server
 	port := ":8080"
 	log.Printf("Server starting on port %s\n", port)