NOISSUE - Health metrics

api/endpoints.go

@@ -19,6 +19,12 @@ import (
 
 const svcName = "agent"
 
+func healthEndpoint(svc agent.Service) endpoint.Endpoint {
+	return func(_ context.Context, _ any) (any, error) {
+		return healthRes{Metrics: svc.Health()}, nil
+	}
+}
+
 func pubEndpoint(svc agent.Service) endpoint.Endpoint {
 	return func(_ context.Context, request any) (any, error) {
 		req := request.(pubReq)

api/responses.go

@@ -8,12 +8,14 @@ import (
 
 	"github.com/absmach/agent"
 	"github.com/absmach/agent/pkg/devicemgr"
+	"github.com/absmach/agent/pkg/health"
 	"github.com/absmach/magistrala"
 )
 
 var (
 	_ magistrala.Response = (*publishRes)(nil)
 	_ magistrala.Response = (*execRes)(nil)
+	_ magistrala.Response = (*healthRes)(nil)
 	_ magistrala.Response = (*addConfigRes)(nil)
 	_ magistrala.Response = (*viewConfigRes)(nil)
 	_ magistrala.Response = (*viewServicesRes)(nil)
@@ -244,3 +246,22 @@ func (res otaStatusRes) Headers() map[string]string {
 func (res otaStatusRes) Empty() bool {
 	return false
 }
+
+type healthRes struct {
+	*health.Metrics
+}
+
+func (res healthRes) Code() int {
+	if res.Metrics == nil {
+		return http.StatusServiceUnavailable
+	}
+	return http.StatusOK
+}
+
+func (res healthRes) Headers() map[string]string {
+	return map[string]string{}
+}
+
+func (res healthRes) Empty() bool {
+	return res.Metrics == nil
+}

api/transport.go

@@ -145,6 +145,13 @@ func MakeHandler(svc agent.Service, logger *slog.Logger, stream *logstream.Strea
 	})
 	r.Handle("/ui/*", http.StripPrefix("/ui", agentui.Handler()))
 
+	r.Get("/api/health", kithttp.NewServer(
+		healthEndpoint(svc),
+		decodeRequest,
+		EncodeResponse,
+		opts...,
+	).ServeHTTP)
+
 	return r
 }
 

middleware/logging.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/absmach/agent"
 	"github.com/absmach/agent/pkg/devicemgr"
+	"github.com/absmach/agent/pkg/health"
 	"github.com/go-chi/chi/v5/middleware"
 )
 
@@ -224,6 +225,14 @@ func (lm *loggingMiddleware) OTA(ctx context.Context, url, sha256hex string, siz
 	return lm.svc.OTA(ctx, url, sha256hex, size)
 }
 
+func (lm *loggingMiddleware) Health() *health.Metrics {
+	defer func(begin time.Time) {
+		lm.logger.Info("Retrieve health completed successfully.", slog.String("duration", time.Since(begin).String()))
+	}(time.Now())
+
+	return lm.svc.Health()
+}
+
 func (lm *loggingMiddleware) NodeRed(cmdStr string) (resp string, err error) {
 	defer func(begin time.Time) {
 		args := []any{

middleware/metrics.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/absmach/agent"
 	"github.com/absmach/agent/pkg/devicemgr"
+	"github.com/absmach/agent/pkg/health"
 	"github.com/go-kit/kit/metrics"
 )
 
@@ -149,6 +150,15 @@ func (ms *metricsMiddleware) OTA(ctx context.Context, url, sha256hex string, siz
 	return ms.svc.OTA(ctx, url, sha256hex, size)
 }
 
+func (ms *metricsMiddleware) Health() *health.Metrics {
+	defer func(begin time.Time) {
+		ms.counter.With("method", "health").Add(1)
+		ms.latency.With("method", "health").Observe(time.Since(begin).Seconds())
+	}(time.Now())
+
+	return ms.svc.Health()
+}
+
 func (ms *metricsMiddleware) NodeRed(cmdStr string) (string, error) {
 	defer func(begin time.Time) {
 		ms.counter.With("method", "nodered").Add(1)