ping db in health check

api.go

@@ -30,6 +30,44 @@ const (
 	)
 )
 
+func (h *Headscale) HealthHandler(
+	writer http.ResponseWriter,
+	req *http.Request,
+) {
+	respond := func(err error) {
+		writer.Header().Set("Content-Type", "application/health+json; charset=utf-8")
+
+		res := struct {
+			Status string `json:"status"`
+		}{
+			Status: "pass",
+		}
+
+		if err != nil {
+			writer.WriteHeader(http.StatusInternalServerError)
+			log.Error().Caller().Err(err).Msg("health check failed")
+			res.Status = "fail"
+		}
+
+		buf, err := json.Marshal(res)
+		if err != nil {
+			log.Error().Caller().Err(err).Msg("marshal failed")
+		}
+		_, err = writer.Write(buf)
+		if err != nil {
+			log.Error().Caller().Err(err).Msg("write failed")
+		}
+	}
+
+	if err := h.pingDB(); err != nil {
+		respond(err)
+
+		return
+	}
+
+	respond(nil)
+}
+
 // KeyHandler provides the Headscale pub key
 // Listens in /key.
 func (h *Headscale) KeyHandler(

app.go

@@ -423,19 +423,7 @@ func (h *Headscale) createPrometheusRouter() *gin.Engine {
 func (h *Headscale) createRouter(grpcMux *runtime.ServeMux) *mux.Router {
 	router := mux.NewRouter()
 
-	router.HandleFunc(
-		"/health",
-		func(writer http.ResponseWriter, req *http.Request) {
-			writer.WriteHeader(http.StatusOK)
-			_, err := writer.Write([]byte("{\"healthy\": \"ok\"}"))
-			if err != nil {
-				log.Error().
-					Caller().
-					Err(err).
-					Msg("Failed to write response")
-			}
-		}).Methods(http.MethodGet)
-
+	router.HandleFunc("/health", h.HealthHandler).Methods(http.MethodGet)
 	router.HandleFunc("/key", h.KeyHandler).Methods(http.MethodGet)
 	router.HandleFunc("/register", h.RegisterWebAPI).Methods(http.MethodGet)
 	router.HandleFunc("/machine/{mkey}/map", h.PollNetMapHandler).Methods(http.MethodPost)

db.go

@@ -1,6 +1,7 @@
 package headscale
 
 import (
+	"context"
 	"database/sql/driver"
 	"encoding/json"
 	"errors"
@@ -220,6 +221,17 @@ func (h *Headscale) setValue(key string, value string) error {
 	return nil
 }
 
+func (h *Headscale) pingDB() error {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+	db, err := h.db.DB()
+	if err != nil {
+		return err
+	}
+
+	return db.PingContext(ctx)
+}
+
 // This is a "wrapper" type around tailscales
 // Hostinfo to allow us to add database "serialization"
 // methods. This allows us to use a typed values throughout