enabled prometheus metrics

cmd/scality-cosi-driver/cmd.go

@@ -20,21 +20,25 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"time"
 
 	"github.com/scality/cosi-driver/pkg/driver"
-	"k8s.io/klog/v2"
-
 	"github.com/scality/cosi-driver/pkg/grpcfactory"
+	"github.com/scality/cosi-driver/pkg/metrics"
+	"k8s.io/klog/v2"
 )
 
 const (
+	// TODO: add to constants
 	provisionerName     = "scality.com"
 	defaultDriverPrefix = "cosi"
 )
 
 var (
-	driverAddress = flag.String("driver-address", "unix:///var/lib/cosi/cosi.sock", "driver address for the socket")
-	driverPrefix  = flag.String("driver-prefix", "", "prefix for COSI driver, e.g. <prefix>.scality.com")
+	// TODO: add to constants
+	driverAddress  = flag.String("driver-address", "unix:///var/lib/cosi/cosi.sock", "driver address for the socket")
+	driverPrefix   = flag.String("driver-prefix", "", "prefix for COSI driver, e.g. <prefix>.scality.com")
+	metricsAddress = flag.String("metrics-address", ":8080", "The address to expose Prometheus metrics.")
 )
 
 func init() {
@@ -53,8 +57,12 @@ func init() {
 }
 
 func run(ctx context.Context) error {
-	driverName := *driverPrefix + "." + provisionerName
+	metricsServer, err := metrics.StartMetricsServer(*metricsAddress)
+	if err != nil {
+		return fmt.Errorf("failed to start metrics server: %w", err)
+	}
 
+	driverName := *driverPrefix + "." + provisionerName
 	identityServer, bucketProvisioner, err := driver.CreateDriver(ctx, driverName)
 	if err != nil {
 		return fmt.Errorf("failed to initialize Scality driver: %w", err)
@@ -65,5 +73,12 @@ func run(ctx context.Context) error {
 		return fmt.Errorf("failed to start the provisioner server: %w", err)
 	}
 
-	return server.Run(ctx)
+	err = server.Run(ctx)
+	shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer shutdownCancel()
+	if err2 := metricsServer.Shutdown(shutdownCtx); err2 != nil {
+		klog.ErrorS(err2, "Failed to gracefully shutdown metrics server")
+	}
+
+	return err
 }

cmd/scality-cosi-driver/main.go

@@ -47,8 +47,8 @@ func main() {
 		}
 	}()
 
-	// Call the run function (defined in cmd.go)
 	if err := run(ctx); err != nil {
 		klog.ErrorS(err, "Scality COSI driver encountered an error, shutting down")
+		os.Exit(1)
 	}
 }

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/aws/smithy-go v1.22.1
 	github.com/onsi/ginkgo/v2 v2.22.0
 	github.com/onsi/gomega v1.36.1
+	github.com/prometheus/client_golang v1.12.1
 	google.golang.org/grpc v1.69.0
 	k8s.io/client-go v0.31.3
 	k8s.io/klog/v2 v2.130.1
@@ -28,6 +29,12 @@ require (
 	github.com/aws/aws-sdk-go-v2/service/sso v1.24.7 // indirect
 	github.com/aws/aws-sdk-go-v2/service/ssooidc v1.28.6 // indirect
 	github.com/aws/aws-sdk-go-v2/service/sts v1.33.2 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/common v0.32.1 // indirect
+	github.com/prometheus/procfs v0.7.3 // indirect
 	gopkg.in/evanphx/json-patch.v4 v4.12.0 // indirect
 )