Append basic prometheus metrics

cmd/neofs-oauthz/app.go

@@ -30,6 +30,8 @@ type (
 		cfg       *viper.Viper
 		webServer *http.Server
 		webDone   chan struct{}
+
+		gateMetrics *gateMetrics
 	}
 
 	// App is an interface for the main gateway function.
@@ -65,16 +67,28 @@ func WithConfig(c *viper.Viper) Option {
 func newApp(ctx context.Context, opt ...Option) App {
 	var err error
 	a := &app{
-		log:       zap.L(),
-		cfg:       viper.GetViper(),
-		webServer: new(http.Server),
-		webDone:   make(chan struct{}),
+		log:         zap.L(),
+		cfg:         viper.GetViper(),
+		webServer:   new(http.Server),
+		webDone:     make(chan struct{}),
+		gateMetrics: newGateMetrics(),
 	}
 
 	for i := range opt {
 		opt[i](a)
 	}
 
+	a.gateMetrics.SetAppVersion(Version)
+
+	prometheusService := newPrometheus(
+		a.log,
+		a.cfg.GetBool(cfgPrometheusEnabled),
+		a.cfg.GetString(cfgPrometheusAddress),
+	)
+
+	services := newServices([]*service{prometheusService})
+	services.RunServices()
+
 	key, err := a.getKey()
 	if err != nil {
 		a.log.Fatal("failed to get neofs credentials", zap.Error(err))
@@ -293,6 +307,8 @@ func (a *app) Serve(ctx context.Context) {
 	myHandler.HandleFunc("/callback", authenticator.Callback)
 	a.webServer.Handler = myHandler
 
+	a.gateMetrics.SetServiceStarted()
+
 	a.webServer.Addr = a.authCfg.Host
 	if a.authCfg.TLSEnabled {
 		a.log.Info("running web server (TLS-enabled)", zap.String("address", a.webServer.Addr))

cmd/neofs-oauthz/app_metrics.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"go.uber.org/zap"
+)
+
+const (
+	namespace = "neofs_oauthz"
+)
+
+type (
+	// gateMetrics is a metrics collection.
+	gateMetrics struct {
+		stateMetrics
+	}
+
+	stateMetrics struct {
+		up        prometheus.Gauge
+		gwVersion *prometheus.GaugeVec
+	}
+)
+
+// newGateMetrics creates new metrics for the app.
+func newGateMetrics() *gateMetrics {
+	stateMetric := newStateMetrics()
+	stateMetric.register()
+
+	return &gateMetrics{
+		stateMetrics: *stateMetric,
+	}
+}
+
+func newStateMetrics() *stateMetrics {
+	return &stateMetrics{
+		up: prometheus.NewGauge(prometheus.GaugeOpts{
+			Namespace: namespace,
+			Name:      "up",
+			Help:      "App is up and running",
+		}),
+		gwVersion: prometheus.NewGaugeVec(
+			prometheus.GaugeOpts{
+				Help:      "App version",
+				Name:      "version",
+				Namespace: namespace,
+			},
+			[]string{"version"},
+		),
+	}
+}
+
+func (m stateMetrics) register() {
+	prometheus.MustRegister(m.up)
+	prometheus.MustRegister(m.gwVersion)
+}
+
+// SetServiceStarted updates the `up` metric with the value 1.
+func (m stateMetrics) SetServiceStarted() {
+	m.up.Set(1.0)
+}
+
+// newPrometheus creates a new service for gathering prometheus metrics.
+func newPrometheus(log *zap.Logger, enabled bool, address string) *service {
+	return newService(
+		&http.Server{
+			Addr:    address,
+			Handler: promhttp.Handler(),
+		},
+		enabled,
+		log.With(zap.String("service", "Prometheus")),
+	)
+}
+
+// SetAppVersion increments the app version metric counter for the specified version label.
+func (g *gateMetrics) SetAppVersion(ver string) {
+	g.gwVersion.WithLabelValues(ver).Add(1)
+}

cmd/neofs-oauthz/config.go

@@ -60,6 +60,9 @@ const (
 	cfgOauthEndpointTokenFmt = "oauth.%s.endpoint.token"
 	cfgRedirectURL           = "redirect.url"
 	callbackURLFmt           = "%scallback"
+
+	cfgPrometheusEnabled = "prometheus.enabled"
+	cfgPrometheusAddress = "prometheus.address"
 )
 
 var ignore = map[string]struct{}{

cmd/neofs-oauthz/service.go

@@ -0,0 +1,91 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"time"
+
+	"go.uber.org/zap"
+)
+
+const defaultShutdownTimeout = 15 * time.Second
+
+type (
+	// service serves metrics.
+	service struct {
+		*http.Server
+		enabled bool
+		log     *zap.Logger
+	}
+
+	// services is a collection for services which can be started in background.
+	services struct {
+		services []*service
+	}
+)
+
+// newService is a constructor for service.
+func newService(
+	server *http.Server,
+	enabled bool,
+	log *zap.Logger,
+) *service {
+	return &service{
+		Server:  server,
+		enabled: enabled,
+		log:     log,
+	}
+}
+
+// Start runs http service with the exposed endpoint on the configured port.
+func (ms *service) Start() {
+	if !ms.enabled {
+		ms.log.Info("service hasn't started since it's disabled")
+	}
+
+	ms.log.Info("service is running", zap.String("endpoint", ms.Addr))
+
+	if err := ms.ListenAndServe(); err != nil {
+		if !errors.Is(err, http.ErrServerClosed) {
+			ms.log.Warn("service couldn't start on configured port", zap.Error(err))
+		}
+	}
+}
+
+// ShutDown stops the service.
+func (ms *service) ShutDown(ctx context.Context) {
+	ms.log.Info("shutting down service", zap.String("endpoint", ms.Addr))
+
+	if err := ms.Shutdown(ctx); err != nil {
+		ms.log.Panic("can't shut down service", zap.Error(err))
+	}
+}
+
+// newServices is a constructor for services.
+func newServices(servioceList []*service) *services {
+	return &services{
+		services: servioceList,
+	}
+}
+
+// RunServices function runs all services.
+func (x *services) RunServices() {
+	for _, s := range x.services {
+		go s.Start()
+	}
+}
+
+// StopServices function is shutting down all services.
+func (x *services) StopServices() {
+	ctx, cancel := shutdownContext()
+	defer cancel()
+
+	for _, s := range x.services {
+		go s.ShutDown(ctx)
+	}
+}
+
+func shutdownContext() (context.Context, context.CancelFunc) {
+	return context.WithTimeout(context.Background(), defaultShutdownTimeout)
+}

config/config.yaml

@@ -46,3 +46,7 @@ bearer_cookie_name: "Bearer"
 connect_timeout: 30s
 request_timeout: 15s
 rebalance_timer: 15s
+
+prometheus:
+  enabled: true
+  address: localhost:9986

go.mod

@@ -5,6 +5,7 @@ go 1.22
 require (
 	github.com/nspcc-dev/neo-go v0.106.3
 	github.com/nspcc-dev/neofs-sdk-go v1.0.0-rc.12
+	github.com/prometheus/client_golang v1.20.3
 	github.com/spf13/pflag v1.0.5
 	github.com/spf13/viper v1.19.0
 	go.uber.org/zap v1.27.0
@@ -13,22 +14,29 @@ require (
 
 require (
 	github.com/antlr/antlr4/runtime/Go/antlr/v4 v4.0.0-20221202181307-76fa05c21b12 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/cpuguy83/go-md2man/v2 v2.0.4 // indirect
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.2.0 // indirect
 	github.com/fsnotify/fsnotify v1.7.0 // indirect
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/hashicorp/golang-lru/v2 v2.0.7 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
+	github.com/klauspost/compress v1.17.9 // indirect
 	github.com/magiconair/properties v1.8.7 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/mr-tron/base58 v1.2.0 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/nspcc-dev/go-ordered-json v0.0.0-20240301084351-0246b013f8b2 // indirect
 	github.com/nspcc-dev/hrw/v2 v2.0.1 // indirect
 	github.com/nspcc-dev/neofs-api-go/v2 v2.14.1-0.20240305074711-35bc78d84dc4 // indirect
 	github.com/nspcc-dev/rfc6979 v0.2.1 // indirect
 	github.com/nspcc-dev/tzhash v1.7.2 // indirect
 	github.com/pelletier/go-toml/v2 v2.2.2 // indirect
+	github.com/prometheus/client_model v0.6.1 // indirect
+	github.com/prometheus/common v0.55.0 // indirect
+	github.com/prometheus/procfs v0.15.1 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/sagikazarmark/locafero v0.4.0 // indirect
 	github.com/sagikazarmark/slog-shim v0.1.0 // indirect
@@ -40,15 +48,15 @@ require (
 	github.com/urfave/cli/v2 v2.27.2 // indirect
 	github.com/xrash/smetrics v0.0.0-20240312152122-5f08fbb34913 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
-	golang.org/x/crypto v0.21.0 // indirect
+	golang.org/x/crypto v0.24.0 // indirect
 	golang.org/x/exp v0.0.0-20240222234643-814bf88cf225 // indirect
-	golang.org/x/net v0.23.0 // indirect
-	golang.org/x/sys v0.18.0 // indirect
-	golang.org/x/term v0.18.0 // indirect
-	golang.org/x/text v0.14.0 // indirect
+	golang.org/x/net v0.26.0 // indirect
+	golang.org/x/sys v0.22.0 // indirect
+	golang.org/x/term v0.21.0 // indirect
+	golang.org/x/text v0.16.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20240314234333-6e1732d8331c // indirect
 	google.golang.org/grpc v1.62.1 // indirect
-	google.golang.org/protobuf v1.33.0 // indirect
+	google.golang.org/protobuf v1.34.2 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )