Add metrics (#119)

.github/workflows/docker.yml

@@ -22,7 +22,7 @@ jobs:
     steps:
 
     - name: Set up Go 1.20
-      uses: actions/setup-go@v3
+      uses: actions/setup-go@v4
       with:
         go-version: "1.20"
       id: go
@@ -87,7 +87,7 @@ jobs:
     steps:
 
     - name: Set up Go 1.20
-      uses: actions/setup-go@v3
+      uses: actions/setup-go@v4
       with:
         go-version: "1.20"
       id: go

cmd/server/main.go

@@ -27,6 +27,12 @@ func main() {
 				Usage:   "gRPC server endpoint",
 				EnvVars: []string{"GOIPAM_GRPC_SERVER_ENDPOINT"},
 			},
+			&cli.StringFlag{
+				Name:    "metrics-endpoint",
+				Value:   "localhost:2112",
+				Usage:   "metrics endpoint",
+				EnvVars: []string{"GOIPAM_METRICS_ENDPOINT"},
+			},
 			&cli.StringFlag{
 				Name:    "log-level",
 				Value:   "info",
@@ -291,6 +297,7 @@ func getConfig(ctx *cli.Context) config {
 
 	return config{
 		GrpcServerEndpoint: ctx.String("grpc-server-endpoint"),
+		MetricsEndpoint:    ctx.String("metrics-endpoint"),
 		Log:                zlog.Sugar(),
 	}
 }

cmd/server/server.go

@@ -4,11 +4,16 @@ import (
 	"net/http"
 	"time"
 
+	"github.com/bufbuild/connect-go"
+	otelconnect "github.com/bufbuild/connect-opentelemetry-go"
 	compress "github.com/klauspost/connect-compress"
 	goipam "github.com/metal-stack/go-ipam"
 	"github.com/metal-stack/go-ipam/api/v1/apiv1connect"
 	"github.com/metal-stack/go-ipam/pkg/service"
 	"github.com/metal-stack/v"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"go.opentelemetry.io/otel/exporters/prometheus"
+	"go.opentelemetry.io/otel/sdk/metric"
 
 	grpchealth "github.com/bufbuild/connect-grpchealth-go"
 	grpcreflect "github.com/bufbuild/connect-grpcreflect-go"
@@ -20,6 +25,7 @@ import (
 
 type config struct {
 	GrpcServerEndpoint string
+	MetricsEndpoint    string
 	Log                *zap.SugaredLogger
 	Storage            goipam.Storage
 }
@@ -40,10 +46,44 @@ func newServer(c config) *server {
 }
 func (s *server) Run() error {
 	s.log.Infow("starting go-ipam", "version", v.V, "backend", s.storage.Name())
+
+	// The exporter embeds a default OpenTelemetry Reader and
+	// implements prometheus.Collector, allowing it to be used as
+	// both a Reader and Collector.
+	exporter, err := prometheus.New()
+	if err != nil {
+		return err
+	}
+	provider := metric.NewMeterProvider(metric.WithReader(exporter))
+
+	// Start the prometheus HTTP server and pass the exporter Collector to it
+	go func() {
+		s.log.Infof("serving metrics at %s/metrics", s.c.MetricsEndpoint)
+		metricsServer := http.NewServeMux()
+		metricsServer.Handle("/metrics", promhttp.Handler())
+		ms := &http.Server{
+			Addr:              s.c.MetricsEndpoint,
+			Handler:           metricsServer,
+			ReadHeaderTimeout: time.Minute,
+		}
+		err := ms.ListenAndServe()
+		if err != nil {
+			s.log.Errorw("unable to start metric endpoint", "error", err)
+			return
+		}
+	}()
+
 	mux := http.NewServeMux()
 	// The generated constructors return a path and a plain net/http
 	// handler.
-	mux.Handle(apiv1connect.NewIpamServiceHandler(service.New(s.log, s.ipamer)))
+	mux.Handle(
+		apiv1connect.NewIpamServiceHandler(
+			service.New(s.log, s.ipamer),
+			connect.WithInterceptors(
+				otelconnect.NewInterceptor(otelconnect.WithMeterProvider(provider)),
+			),
+		),
+	)
 
 	mux.Handle(grpchealth.NewHandler(
 		grpchealth.NewStaticChecker(apiv1connect.IpamServiceName),
@@ -62,6 +102,6 @@ func (s *server) Run() error {
 		ReadHeaderTimeout: 1 * time.Minute,
 	}
 
-	err := server.ListenAndServe()
+	err = server.ListenAndServe()
 	return err
 }

go.mod

@@ -4,80 +4,97 @@ go 1.20
 
 require (
 	github.com/avast/retry-go/v4 v4.3.4
-	github.com/bufbuild/connect-go v1.7.0
-	github.com/bufbuild/connect-grpchealth-go v1.1.0
-	github.com/bufbuild/connect-grpcreflect-go v1.0.0
+	github.com/bufbuild/connect-go v1.9.0
+	github.com/bufbuild/connect-grpchealth-go v1.1.1
+	github.com/bufbuild/connect-grpcreflect-go v1.1.0
+	github.com/bufbuild/connect-opentelemetry-go v0.4.0
 	github.com/jmoiron/sqlx v1.3.5
 	github.com/klauspost/connect-compress v1.0.0
 	github.com/lib/pq v1.10.9
 	github.com/metal-stack/v v1.0.3
-	github.com/redis/go-redis/v9 v9.0.4
-	github.com/stretchr/testify v1.8.2
-	github.com/testcontainers/testcontainers-go v0.20.1
-	github.com/urfave/cli/v2 v2.25.3
+	github.com/prometheus/client_golang v1.16.0
+	github.com/redis/go-redis/v9 v9.0.5
+	github.com/stretchr/testify v1.8.4
+	github.com/testcontainers/testcontainers-go v0.21.0
+	github.com/urfave/cli/v2 v2.25.7
 	go.etcd.io/etcd/client/v3 v3.5.9
-	go.mongodb.org/mongo-driver v1.11.6
+	go.mongodb.org/mongo-driver v1.12.0
+	go.opentelemetry.io/otel/exporters/prometheus v0.39.0
+	go.opentelemetry.io/otel/sdk/metric v0.39.0
 	go.uber.org/zap v1.24.0
 	go4.org/netipx v0.0.0-20230303233057-f1b76eb4bb35
-	golang.org/x/net v0.10.0
-	golang.org/x/sync v0.2.0
-	google.golang.org/protobuf v1.30.0
+	golang.org/x/net v0.12.0
+	golang.org/x/sync v0.3.0
+	google.golang.org/protobuf v1.31.0
 )
 
 require (
 	github.com/Azure/go-ansiterm v0.0.0-20230124172434-306776ec8161 // indirect
 	github.com/Microsoft/go-winio v0.6.1 // indirect
-	github.com/benbjohnson/clock v1.3.4 // indirect
+	github.com/benbjohnson/clock v1.3.5 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cenkalti/backoff/v4 v4.2.1 // indirect
 	github.com/cespare/xxhash/v2 v2.2.0 // indirect
-	github.com/containerd/containerd v1.7.1 // indirect
+	github.com/containerd/containerd v1.7.2 // indirect
 	github.com/coreos/go-semver v0.3.1 // indirect
 	github.com/coreos/go-systemd/v22 v22.5.0 // indirect
 	github.com/cpuguy83/dockercfg v0.3.1 // indirect
 	github.com/cpuguy83/go-md2man/v2 v2.0.2 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
 	github.com/docker/distribution v2.8.2+incompatible // indirect
-	github.com/docker/docker v24.0.0+incompatible // indirect
+	github.com/docker/docker v24.0.4+incompatible // indirect
 	github.com/docker/go-connections v0.4.0 // indirect
 	github.com/docker/go-units v0.5.0 // indirect
+	github.com/go-logr/logr v1.2.4 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/google/uuid v1.3.0 // indirect
-	github.com/imdario/mergo v0.3.13 // indirect
-	github.com/klauspost/compress v1.16.5 // indirect
-	github.com/kr/text v0.2.0 // indirect
+	github.com/imdario/mergo v0.3.15 // indirect
+	github.com/klauspost/compress v1.16.7 // indirect
 	github.com/magiconair/properties v1.8.7 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
 	github.com/moby/patternmatcher v0.5.0 // indirect
 	github.com/moby/sys/sequential v0.5.0 // indirect
 	github.com/moby/term v0.5.0 // indirect
 	github.com/montanaflynn/stats v0.7.1 // indirect
 	github.com/morikuni/aec v1.0.0 // indirect
 	github.com/opencontainers/go-digest v1.0.0 // indirect
-	github.com/opencontainers/image-spec v1.1.0-rc3 // indirect
+	github.com/opencontainers/image-spec v1.1.0-rc4 // indirect
 	github.com/opencontainers/runc v1.1.7 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_model v0.4.0 // indirect
+	github.com/prometheus/common v0.44.0 // indirect
+	github.com/prometheus/procfs v0.11.0 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
-	github.com/sirupsen/logrus v1.9.1 // indirect
+	github.com/sirupsen/logrus v1.9.3 // indirect
 	github.com/xdg-go/pbkdf2 v1.0.0 // indirect
 	github.com/xdg-go/scram v1.1.2 // indirect
 	github.com/xdg-go/stringprep v1.0.4 // indirect
 	github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 // indirect
 	github.com/youmark/pkcs8 v0.0.0-20201027041543-1326539a0a0a // indirect
 	go.etcd.io/etcd/api/v3 v3.5.9 // indirect
 	go.etcd.io/etcd/client/pkg/v3 v3.5.9 // indirect
+	go.opentelemetry.io/otel v1.16.0 // indirect
+	go.opentelemetry.io/otel/metric v1.16.0 // indirect
+	go.opentelemetry.io/otel/sdk v1.16.0 // indirect
+	go.opentelemetry.io/otel/trace v1.16.0 // indirect
 	go.uber.org/atomic v1.11.0 // indirect
 	go.uber.org/goleak v1.2.1 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
-	golang.org/x/crypto v0.9.0 // indirect
-	golang.org/x/mod v0.10.0 // indirect
-	golang.org/x/sys v0.8.0 // indirect
-	golang.org/x/text v0.9.0 // indirect
-	golang.org/x/tools v0.9.1 // indirect
-	google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1 // indirect
-	google.golang.org/grpc v1.55.0 // indirect
+	golang.org/x/crypto v0.11.0 // indirect
+	golang.org/x/exp v0.0.0-20230626212559-97b1e661b5df // indirect
+	golang.org/x/mod v0.12.0 // indirect
+	golang.org/x/sys v0.10.0 // indirect
+	golang.org/x/text v0.11.0 // indirect
+	golang.org/x/tools v0.11.0 // indirect
+	google.golang.org/genproto v0.0.0-20230706204954-ccb25ca9f130 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20230706204954-ccb25ca9f130 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20230706204954-ccb25ca9f130 // indirect
+	google.golang.org/grpc v1.56.2 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
-	gotest.tools/v3 v3.4.0 // indirect
+	gotest.tools/v3 v3.5.0 // indirect
 )