feat: add metrics for provider

Signed-off-by: Anish Ramasekar <anish.ramasekar@gmail.com>

chore: update to latest version of otel

Signed-off-by: Anish Ramasekar <anish.ramasekar@gmail.com>

cmd/main.go

@@ -14,6 +14,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/Azure/secrets-store-csi-driver-provider-azure/pkg/metrics"
 	"github.com/Azure/secrets-store-csi-driver-provider-azure/pkg/provider"
 	"github.com/Azure/secrets-store-csi-driver-provider-azure/pkg/server"
 	"github.com/Azure/secrets-store-csi-driver-provider-azure/pkg/utils"
@@ -71,6 +72,11 @@ func main() {
 			klog.ErrorS(http.ListenAndServe(addr, nil), "unable to start profiling server")
 		}()
 	}
+	// initialize metrics exporter before creating measurements
+	err := metrics.InitMetricsExporter()
+	if err != nil {
+		klog.Fatalf("failed to initialize metrics exporter, error: %+v", err)
+	}
 
 	if *provider.ConstructPEMChain {
 		klog.Infof("construct pem chain feature enabled")
@@ -106,9 +112,10 @@ func main() {
 		grpc.UnaryInterceptor(utils.LogGRPC),
 	}
 	s := grpc.NewServer(opts...)
-	k8spb.RegisterCSIDriverProviderServer(s, &server.CSIDriverProviderServer{})
+	csiDriverProviderServer := server.New()
+	k8spb.RegisterCSIDriverProviderServer(s, csiDriverProviderServer)
 	// Register the health service.
-	grpc_health_v1.RegisterHealthServer(s, &server.CSIDriverProviderServer{})
+	grpc_health_v1.RegisterHealthServer(s, csiDriverProviderServer)
 
 	klog.Infof("Listening for connections on address: %v", listener.Addr())
 	go s.Serve(listener)

go.mod

@@ -4,19 +4,22 @@ go 1.16
 
 require (
 	github.com/Azure/azure-sdk-for-go v52.4.0+incompatible
-	github.com/Azure/go-autorest/autorest v0.11.1
-	github.com/Azure/go-autorest/autorest/adal v0.9.5
+	github.com/Azure/go-autorest/autorest v0.11.18
+	github.com/Azure/go-autorest/autorest/adal v0.9.13
 	github.com/Azure/go-autorest/autorest/to v0.4.0 // indirect
 	github.com/Azure/go-autorest/autorest/validation v0.3.1 // indirect
-	github.com/google/go-cmp v0.5.2
-	github.com/kubernetes-csi/csi-lib-utils v0.7.1
+	github.com/google/go-cmp v0.5.5
+	github.com/kubernetes-csi/csi-lib-utils v0.10.0
 	github.com/pkg/errors v0.9.1
-	github.com/stretchr/testify v1.6.1
-	golang.org/x/crypto v0.0.0-20201216223049-8b5274cf687f
-	golang.org/x/net v0.0.0-20201110031124-69a78807bb2b
-	google.golang.org/grpc v1.31.0
-	gopkg.in/yaml.v2 v2.3.0
-	k8s.io/component-base v0.20.2
-	k8s.io/klog/v2 v2.5.0
-	sigs.k8s.io/secrets-store-csi-driver v0.0.21
+	github.com/stretchr/testify v1.7.0
+	go.opentelemetry.io/otel v0.20.0
+	go.opentelemetry.io/otel/exporters/metric/prometheus v0.20.0
+	go.opentelemetry.io/otel/metric v0.20.0
+	golang.org/x/crypto v0.0.0-20210220033148-5ea612d1eb83
+	golang.org/x/net v0.0.0-20210520170846-37e1c6afe023
+	google.golang.org/grpc v1.38.0
+	gopkg.in/yaml.v2 v2.4.0
+	k8s.io/component-base v0.22.0
+	k8s.io/klog/v2 v2.9.0
+	sigs.k8s.io/secrets-store-csi-driver v0.3.0
 )

pkg/metrics/exporter.go

@@ -0,0 +1,28 @@
+package metrics
+
+import (
+	"flag"
+	"fmt"
+	"strings"
+
+	"k8s.io/klog/v2"
+)
+
+var (
+	metricsBackend = flag.String("metrics-backend", "Prometheus", "Backend used for metrics")
+	prometheusPort = flag.Int("prometheus-port", 8898, "Prometheus port for metrics backend")
+)
+
+const prometheusExporter = "prometheus"
+
+func InitMetricsExporter() error {
+	mb := strings.ToLower(*metricsBackend)
+	klog.Infof("metrics backend: %s", mb)
+	switch mb {
+	// Prometheus is the only exporter for now
+	case prometheusExporter:
+		return initPrometheusExporter()
+	default:
+		return fmt.Errorf("unsupported metrics backend %v", *metricsBackend)
+	}
+}

pkg/metrics/prometheus_exporter.go

@@ -0,0 +1,24 @@
+package metrics
+
+import (
+	"fmt"
+	"net/http"
+
+	"go.opentelemetry.io/otel/exporters/metric/prometheus"
+)
+
+func initPrometheusExporter() error {
+	pusher, err := prometheus.InstallNewPipeline(prometheus.Config{
+		DefaultHistogramBoundaries: []float64{
+			0.1, 0.2, 0.3, 0.4, 0.5, 1, 1.5, 2, 2.5, 3.0, 5.0, 10.0, 15.0, 30.0,
+		}})
+	if err != nil {
+		return err
+	}
+	http.HandleFunc("/", pusher.ServeHTTP)
+	go func() {
+		_ = http.ListenAndServe(fmt.Sprintf(":%v", *prometheusPort), nil)
+	}()
+
+	return err
+}