feat: allow to disable '/metrics' endpoints for local stats (#3945)

Seem the "/metrics" endpoint that is source of confusion as people tends
to believe we collect telemetry data just because we import
"opentelemetry", however it is still a good idea to allow to disable
even local metrics if not really required.

See also: #3942

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

core/cli/run.go

@@ -53,6 +53,7 @@ type RunCMD struct {
 	OpaqueErrors                       bool     `env:"LOCALAI_OPAQUE_ERRORS" default:"false" help:"If true, all error responses are replaced with blank 500 errors. This is intended only for hardening against information leaks and is normally not recommended." group:"hardening"`
 	UseSubtleKeyComparison             bool     `env:"LOCALAI_SUBTLE_KEY_COMPARISON" default:"false" help:"If true, API Key validation comparisons will be performed using constant-time comparisons rather than simple equality. This trades off performance on each request for resiliancy against timing attacks." group:"hardening"`
 	DisableApiKeyRequirementForHttpGet bool     `env:"LOCALAI_DISABLE_API_KEY_REQUIREMENT_FOR_HTTP_GET" default:"false" help:"If true, a valid API key is not required to issue GET requests to portions of the web ui. This should only be enabled in secure testing environments" group:"hardening"`
+	DisableMetricsEndpoint             bool     `env:"LOCALAI_DISABLE_METRICS_ENDPOINT,DISABLE_METRICS_ENDPOINT" default:"false" help:"Disable the /metrics endpoint" group:"api"`
 	HttpGetExemptedEndpoints           []string `env:"LOCALAI_HTTP_GET_EXEMPTED_ENDPOINTS" default:"^/$,^/browse/?$,^/talk/?$,^/p2p/?$,^/chat/?$,^/text2image/?$,^/tts/?$,^/static/.*$,^/swagger.*$" help:"If LOCALAI_DISABLE_API_KEY_REQUIREMENT_FOR_HTTP_GET is overriden to true, this is the list of endpoints to exempt. Only adjust this in case of a security incident or as a result of a personal security posture review" group:"hardening"`
 	Peer2Peer                          bool     `env:"LOCALAI_P2P,P2P" name:"p2p" default:"false" help:"Enable P2P mode" group:"p2p"`
 	Peer2PeerDHTInterval               int      `env:"LOCALAI_P2P_DHT_INTERVAL,P2P_DHT_INTERVAL" default:"360" name:"p2p-dht-interval" help:"Interval for DHT refresh (used during token generation)" group:"p2p"`
@@ -108,6 +109,10 @@ func (r *RunCMD) Run(ctx *cliContext.Context) error {
 		config.WithLoadToMemory(r.LoadToMemory),
 	}
 
+	if r.DisableMetricsEndpoint {
+		opts = append(opts, config.DisableMetricsEndpoint)
+	}
+
 	token := ""
 	if r.Peer2Peer || r.Peer2PeerToken != "" {
 		log.Info().Msg("P2P mode enabled")

core/config/application_config.go

@@ -39,6 +39,7 @@ type ApplicationConfig struct {
 	OpaqueErrors                       bool
 	UseSubtleKeyComparison             bool
 	DisableApiKeyRequirementForHttpGet bool
+	DisableMetrics                     bool
 	HttpGetExemptedEndpoints           []*regexp.Regexp
 	DisableGalleryEndpoint             bool
 	LoadToMemory                       []string
@@ -350,6 +351,10 @@ func WithDisableApiKeyRequirementForHttpGet(required bool) AppOption {
 	}
 }
 
+var DisableMetricsEndpoint AppOption = func(o *ApplicationConfig) {
+	o.DisableMetrics = true
+}
+
 func WithHttpGetExemptedEndpoints(endpoints []string) AppOption {
 	return func(o *ApplicationConfig) {
 		o.HttpGetExemptedEndpoints = []*regexp.Regexp{}

core/http/app.go

@@ -109,19 +109,21 @@ func App(cl *config.BackendConfigLoader, ml *model.ModelLoader, appConfig *confi
 		app.Use(recover.New())
 	}
 
-	metricsService, err := services.NewLocalAIMetricsService()
-	if err != nil {
-		return nil, err
-	}
+	if !appConfig.DisableMetrics {
+		metricsService, err := services.NewLocalAIMetricsService()
+		if err != nil {
+			return nil, err
+		}
 
-	if metricsService != nil {
-		app.Use(localai.LocalAIMetricsAPIMiddleware(metricsService))
-		app.Hooks().OnShutdown(func() error {
-			return metricsService.Shutdown()
-		})
-	}
+		if metricsService != nil {
+			app.Use(localai.LocalAIMetricsAPIMiddleware(metricsService))
+			app.Hooks().OnShutdown(func() error {
+				return metricsService.Shutdown()
+			})
+		}
 
- // Health Checks should always be exempt from auth, so register these first
+	}
+	// Health Checks should always be exempt from auth, so register these first
 	routes.HealthRoutes(app)
 
 	kaConfig, err := middleware.GetKeyAuthConfig(appConfig)

core/http/routes/localai.go

@@ -42,7 +42,9 @@ func RegisterLocalAIRoutes(app *fiber.App,
 	app.Post("/stores/get", localai.StoresGetEndpoint(sl, appConfig))
 	app.Post("/stores/find", localai.StoresFindEndpoint(sl, appConfig))
 
-	app.Get("/metrics", localai.LocalAIMetricsEndpoint())
+	if !appConfig.DisableMetrics {
+		app.Get("/metrics", localai.LocalAIMetricsEndpoint())
+	}
 
 	// Experimental Backend Statistics Module
 	backendMonitorService := services.NewBackendMonitorService(ml, cl, appConfig) // Split out for now