Add metrics to grpc server

cmd/necoperf-daemon/cmd/daemon.go

@@ -13,6 +13,7 @@ var (
 	port            int
 	runtimeEndpoint string
 	workDir         string
+	metricsPort     int
 )
 
 func NewDaemonCommand() *cobra.Command {
@@ -22,7 +23,7 @@ func NewDaemonCommand() *cobra.Command {
 		RunE: func(cmd *cobra.Command, args []string) error {
 			handler := slog.NewTextHandler(os.Stderr, nil)
 			logger := slog.New(handler)
-			daemon, err := daemon.New(logger, port, runtimeEndpoint, workDir)
+			daemon, err := daemon.New(logger, port, metricsPort, runtimeEndpoint, workDir)
 			if err != nil {
 				return err
 			}
@@ -31,6 +32,7 @@ func NewDaemonCommand() *cobra.Command {
 		},
 	}
 	cmd.Flags().IntVar(&port, "port", constants.NecoPerfGrpcServerPort, "Port number on which the grpc server runs")
+	cmd.Flags().IntVar(&metricsPort, "metrics-port", constants.NecoPerfMetricsPort, "Port number on which the metrics server runs")
 	cmd.Flags().StringVar(&runtimeEndpoint, "runtime-endpoint", "unix:///run/containerd/containerd.sock", "Container runtime endpoint to connect to")
 	cmd.Flags().StringVar(&workDir, "work-dir", "/var/necoperf", "Directory for storing profiling result")
 

docs/necoperf-daemon.md

@@ -13,5 +13,6 @@ Start necoperf-daemon on the server.
 | Option | Default value |Description |
 |:-------|:--------------|:-----------|
 | `--port` | `6543` | Port number on which the grpc server runs |
+| `--metrics-port` | `6541` | Port number on which the metrics server runs |
 | `--runtime-endpoint` | `unix:///run/containerd/containerd.sock` | Container runtime endpoint to connect to |
 | `--work-dir` | `/var/necoperf` | Directory for storing profiling results |

go.mod

@@ -6,10 +6,12 @@ toolchain go1.21.1
 
 require (
 	github.com/google/uuid v1.3.0
+	github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.0.0
 	github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.0.0
 	github.com/oklog/run v1.1.0
 	github.com/onsi/ginkgo/v2 v2.11.0
 	github.com/onsi/gomega v1.27.10
+	github.com/prometheus/client_golang v1.16.0
 	github.com/spf13/cobra v1.7.0
 	github.com/stretchr/testify v1.8.4
 	golang.org/x/sync v0.3.0
@@ -57,7 +59,6 @@ require (
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/prometheus/client_golang v1.16.0 // indirect
 	github.com/prometheus/client_model v0.4.0 // indirect
 	github.com/prometheus/common v0.44.0 // indirect
 	github.com/prometheus/procfs v0.10.1 // indirect

go.sum

@@ -179,6 +179,8 @@ github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
 github.com/googleapis/gax-go/v2 v2.0.5/go.mod h1:DWXyrwAJ9X0FpwwEdw+IPEYBICEFu5mhpdKc/us6bOk=
+github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.0.0 h1:f4tggROQKKcnh4eItay6z/HbHLqghBxS8g7pyMhmDio=
+github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.0.0/go.mod h1:hKAkSgNkL0FII46ZkJcpVEAai4KV+swlIWCKfekd1pA=
 github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.0.0 h1:2cz5kSrxzMYHiWOBbKj8itQm+nRykkB8aMv4ThcHYHA=
 github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.0.0/go.mod h1:w9Y7gY31krpLmrVU5ZPG9H7l9fZuRu5/3R3S3FMtVQ4=
 github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFbcEtjT1g+wF4CSlocrBnw=

internal/constants/constants.go

@@ -15,6 +15,7 @@ const (
 )
 
 const (
+	NecoPerfMetricsPort    = 6541
 	NecoPerfGrpcServerPort = 6543
 	NecoperfGrpcPortName   = "necoperf-grpc"
 )

internal/daemon/daemon.go

@@ -5,13 +5,17 @@ import (
 	"fmt"
 	"log/slog"
 	"net"
+	"net/http"
 	"os"
 	"time"
 
 	"github.com/cybozu-go/necoperf/internal/resource"
 	"github.com/cybozu-go/necoperf/internal/rpc"
+	grpcprom "github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus"
 	"github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors/logging"
 	"github.com/oklog/run"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"golang.org/x/sync/semaphore"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/health"
@@ -22,12 +26,13 @@ import (
 )
 
 type DaemonServer struct {
-	logger    *slog.Logger
-	server    *grpc.Server
-	port      int
-	endpoint  string
-	workDir   string
-	semaphore *semaphore.Weighted
+	logger      *slog.Logger
+	server      *grpc.Server
+	port        int
+	metricsPort int
+	endpoint    string
+	workDir     string
+	semaphore   *semaphore.Weighted
 	rpc.UnimplementedNecoPerfServer
 	container    *resource.Container
 	perfExecuter *resource.PerfExecuter
@@ -39,7 +44,17 @@ const (
 	maxWorkers = 2
 )
 
-func New(logger *slog.Logger, port int, endpoint, workDir string) (*DaemonServer, error) {
+var (
+	reg            = prometheus.NewRegistry()
+	metricsHandler = promhttp.HandlerFor(
+		reg,
+		promhttp.HandlerOpts{
+			ErrorHandling: promhttp.ContinueOnError,
+		},
+	)
+)
+
+func New(logger *slog.Logger, port, metricsPort int, endpoint, workDir string) (*DaemonServer, error) {
 	opts := []logging.Option{
 		logging.WithLogOnEvents(logging.StartCall, logging.FinishCall),
 	}
@@ -48,27 +63,34 @@ func New(logger *slog.Logger, port int, endpoint, workDir string) (*DaemonServer
 		MinTime: minTime,
 	}
 
+	srvMetrics := grpcprom.NewServerMetrics()
+	reg.MustRegister(srvMetrics)
+
 	serv := grpc.NewServer(
 		grpc.ChainUnaryInterceptor(
+			srvMetrics.UnaryServerInterceptor(),
 			logging.UnaryServerInterceptor(InterceptorLogger(logger), opts...),
 		),
 		grpc.ChainStreamInterceptor(
+			srvMetrics.StreamServerInterceptor(),
 			logging.StreamServerInterceptor(InterceptorLogger(logger), opts...),
 		),
 		grpc.KeepaliveEnforcementPolicy(
 			kep,
 		),
 	)
+	srvMetrics.InitializeMetrics(serv)
 
 	semaphore := semaphore.NewWeighted(maxWorkers)
 
 	return &DaemonServer{
-		logger:    logger,
-		server:    serv,
-		port:      port,
-		endpoint:  endpoint,
-		workDir:   workDir,
-		semaphore: semaphore,
+		logger:      logger,
+		server:      serv,
+		port:        port,
+		metricsPort: metricsPort,
+		endpoint:    endpoint,
+		workDir:     workDir,
+		semaphore:   semaphore,
 	}, nil
 }
 
@@ -114,6 +136,20 @@ func (d *DaemonServer) Start() error {
 		d.server.Stop()
 	})
 
+	addr := fmt.Sprintf(":%d", d.metricsPort)
+	metricsServer := &http.Server{Addr: addr}
+	g.Add(func() error {
+		m := http.NewServeMux()
+		m.Handle("/metrics", metricsHandler)
+		metricsServer.Handler = m
+		d.logger.Info("metrics server is running", "port", d.metricsPort)
+		return metricsServer.ListenAndServe()
+	}, func(err error) {
+		if err := metricsServer.Close(); err != nil {
+			d.logger.Error("metrics server shutdown is failed", "error", err)
+		}
+	})
+
 	return g.Run()
 }