add health route

main.go

@@ -36,6 +36,10 @@ type Reading struct {
 	FetchedAt  time.Time `json:"fetched_at"`
 }
 
+type HealthResponse struct {
+	Status string `json:"status"`
+}
+
 func getEnv(key string) string {
 	val := os.Getenv(key)
 	if val == "" {
@@ -243,6 +247,19 @@ func main() {
 		})
 	})
 
+	// GET /health
+	http.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {
+		// TODO: Check if database is ready as well
+		if r.Method != http.MethodGet {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		okStatus := HealthResponse{Status: "ok"}
+
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(okStatus)
+	})
+
 	// GET /weather/history?city=London&limit=10
 	http.HandleFunc("/weather/history", func(w http.ResponseWriter, r *http.Request) {
 		if r.Method != http.MethodGet {