Introduce metrics library

Author: saad-ali

README.md

@@ -55,12 +55,16 @@ Note that the external-provisioner does not scale with more replicas. Only one e
 
 * `--timeout <duration>`: Timeout of all calls to CSI driver. It should be set to value that accommodates majority of `ControllerCreateVolume` and `ControllerDeleteVolume` calls. See [CSI error and timeout handling](#csi-error-and-timeout-handling) for details. 15 seconds is used by default.
 
-* `--retry-interval-start <duration>` - Initial retry interval of failed provisioning or deletion. It doubles with each failure, up to `--retry-interval-max` and then it stops increasing. Default value is 1 second. See [CSI error and timeout handling](#csi-error-and-timeout-handling) for details.
+* `--retry-interval-start <duration>`: Initial retry interval of failed provisioning or deletion. It doubles with each failure, up to `--retry-interval-max` and then it stops increasing. Default value is 1 second. See [CSI error and timeout handling](#csi-error-and-timeout-handling) for details.
 
-* `--retry-interval-max <duration>` - Maximum retry interval of failed provisioning or deletion. Default value is 5 minutes. See [CSI error and timeout handling](#csi-error-and-timeout-handling) for details.
+* `--retry-interval-max <duration>`: Maximum retry interval of failed provisioning or deletion. Default value is 5 minutes. See [CSI error and timeout handling](#csi-error-and-timeout-handling) for details.
 
 * `--worker-threads <num>`: Number of simultaneously running `ControllerCreateVolume` and `ControllerDeleteVolume` operations. Default value is `100`.
 
+* `--metrics-address`: The TCP network address address where the prometheus metrics endpoint will run (example: `:8080` which corresponds to port 8080 on local host). The default is empty string, which means metrics endpoint is disabled.
+
+* `--metrics-path`: The HTTP path where prometheus metrics will be exposed. Default is `/metrics`.
+
 #### Other recognized arguments
 * `--feature-gates <gates>`: A set of comma separated `<feature-name>=<true|false>` pairs that describe feature gates for alpha/experimental features. See [list of features](#feature-status) or `--help` output for list of recognized features. Example: `--feature-gates Topology=true` to enable Topology feature that's disabled by default.
 

cmd/csi-provisioner/csi-provisioner.go

@@ -30,6 +30,7 @@ import (
 
 	"github.com/kubernetes-csi/csi-lib-utils/deprecatedflags"
 	"github.com/kubernetes-csi/csi-lib-utils/leaderelection"
+	"github.com/kubernetes-csi/csi-lib-utils/metrics"
 	ctrl "github.com/kubernetes-csi/external-provisioner/pkg/controller"
 	snapclientset "github.com/kubernetes-csi/external-snapshotter/pkg/client/clientset/versioned"
 	"sigs.k8s.io/sig-storage-lib-external-provisioner/controller"
@@ -43,7 +44,7 @@ import (
 
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/informers"
-	"k8s.io/client-go/listers/core/v1"
+	v1 "k8s.io/client-go/listers/core/v1"
 	storagelisters "k8s.io/client-go/listers/storage/v1beta1"
 	utilflag "k8s.io/component-base/cli/flag"
 	csitrans "k8s.io/csi-translation-lib"
@@ -68,6 +69,9 @@ var (
 	leaderElectionNamespace = flag.String("leader-election-namespace", "", "Namespace where the leader election resource lives. Defaults to the pod namespace if not set.")
 	strictTopology          = flag.Bool("strict-topology", false, "Passes only selected node topology to CreateVolume Request, unlike default behavior of passing aggregated cluster topologies that match with topology keys of the selected node.")
 
+	metricsAddress = flag.String("metrics-address", "", "The TCP network address address where the prometheus metrics endpoint will listen (example: `:8080`). The default is empty string, which means metrics endpoint is disabled.")
+	metricsPath    = flag.String("metrics-path", "/metrics", "The HTTP path where prometheus metrics will be exposed. Default is `/metrics`.")
+
 	featureGates        map[string]bool
 	provisionController *controller.ProvisionController
 	version             = "unknown"
@@ -135,7 +139,9 @@ func main() {
 		klog.Fatalf("Error getting server version: %v", err)
 	}
 
-	grpcClient, err := ctrl.Connect(*csiEndpoint)
+	metricsManager := metrics.NewCSIMetricsManager("" /* driverName */)
+
+	grpcClient, err := ctrl.Connect(*csiEndpoint, metricsManager)
 	if err != nil {
 		klog.Error(err.Error())
 		os.Exit(1)
@@ -153,6 +159,8 @@ func main() {
 		klog.Fatalf("Error getting CSI driver name: %s", err)
 	}
 	klog.V(2).Infof("Detected CSI driver %s", provisionerName)
+	metricsManager.SetDriverName(provisionerName)
+	metricsManager.StartMetricsEndpoint(*metricsAddress, *metricsPath)
 
 	pluginCapabilities, controllerCapabilities, err := ctrl.GetDriverCapabilities(grpcClient, *operationTimeout)
 	if err != nil {

pkg/controller/controller.go

@@ -30,12 +30,13 @@ import (
 
 	"github.com/container-storage-interface/spec/lib/go/csi"
 	"github.com/kubernetes-csi/csi-lib-utils/connection"
+	"github.com/kubernetes-csi/csi-lib-utils/metrics"
 	snapapi "github.com/kubernetes-csi/external-snapshotter/pkg/apis/volumesnapshot/v1beta1"
 	snapclientset "github.com/kubernetes-csi/external-snapshotter/pkg/client/clientset/versioned"
 	"sigs.k8s.io/sig-storage-lib-external-provisioner/controller"
 	"sigs.k8s.io/sig-storage-lib-external-provisioner/util"
 
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	storagev1 "k8s.io/api/storage/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -214,8 +215,8 @@ var (
 	provisionerIDKey = "storage.kubernetes.io/csiProvisionerIdentity"
 )
 
-func Connect(address string) (*grpc.ClientConn, error) {
-	return connection.Connect(address, connection.OnConnectionLoss(connection.ExitOnConnectionLoss()))
+func Connect(address string, metricsManager metrics.CSIMetricsManager) (*grpc.ClientConn, error) {
+	return connection.Connect(address, metricsManager, connection.OnConnectionLoss(connection.ExitOnConnectionLoss()))
 }
 
 func Probe(conn *grpc.ClientConn, singleCallTimeout time.Duration) error {