add health endpoint

cmd/ldap-sql-adapter/main.go

@@ -43,7 +43,7 @@ func main() {
 	defer ldapserver.Stop()
 
 	// Build handler
-	srv := server.NewServer(config, log)
+	srv := server.NewServer(config, log, provider)
 
 	// Start
 	go srv.Start()

internal/provider/provider.go

@@ -11,6 +11,7 @@ var (
 
 // Provider is used to authenticate users
 type Provider interface {
+	Ping(ctx context.Context) error
 	FindUserPasswordByUsername(ctx context.Context, username string) ([]byte, error)
 	FindUserByUsernameOrEmail(ctx context.Context, username string, email string) (User, error)
 	FindUserGroups(ctx context.Context, username string) ([]Group, error)

internal/provider/sql.go

@@ -57,6 +57,11 @@ func NewSQLProvider(config SQLProviderConfig) (*SQLProvider, error) {
 	return &SQLProvider{db: db, config: config}, nil
 }
 
+func (p *SQLProvider) Ping(ctx context.Context) (err error) {
+	defer logMetric("Ping")(err)
+	return p.db.PingContext(ctx)
+}
+
 func (p *SQLProvider) FindUserPasswordByUsername(ctx context.Context, uid string) (passwordBytes []byte, err error) {
 	defer logMetric("FindUserPasswordByUsername")(err)
 	rows, err := p.db.NamedQueryContext(ctx, p.config.SQLGetUserPasswordByUsernameQuery, map[string]any{"uid": uid})

internal/server/server.go

@@ -13,21 +13,24 @@ import (
 	"github.com/rs/zerolog/log"
 
 	"github.com/blesswinsamuel/ldap-sql-proxy/internal/config"
+	"github.com/blesswinsamuel/ldap-sql-proxy/internal/provider"
 )
 
 // Server contains router and handler methods
 type Server struct {
-	router *mux.Router
-	logger zerolog.Logger
-	config *config.Config
+	router   *mux.Router
+	provider provider.Provider
+	logger   zerolog.Logger
+	config   *config.Config
 }
 
 // NewServer creates a new server object and builds router
-func NewServer(cfg *config.Config, logger zerolog.Logger) *Server {
+func NewServer(cfg *config.Config, logger zerolog.Logger, provider provider.Provider) *Server {
 	s := &Server{
-		router: mux.NewRouter(),
-		logger: logger,
-		config: cfg,
+		router:   mux.NewRouter(),
+		logger:   logger,
+		provider: provider,
+		config:   cfg,
 	}
 
 	s.buildRoutes()
@@ -69,6 +72,14 @@ func (s *Server) buildRoutes() {
 	s.router.Use(s.loggerMiddleware)
 
 	s.router.Handle("/metrics", promhttp.Handler())
+	s.router.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {
+		err := s.provider.Ping(r.Context())
+		if err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		w.WriteHeader(http.StatusOK)
+	})
 }
 
 func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {