Changes to accommodate client-go changes and kube vendor update

to v1.18.0

Signed-off-by: Humble Chirammal <hchiramm@redhat.com>

vendor/github.com/kubernetes-csi/csi-lib-utils/metrics/metrics.go

@@ -0,0 +1,199 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package metrics
+
+import (
+	"bufio"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+	"k8s.io/component-base/metrics"
+	"k8s.io/klog"
+)
+
+const (
+	// Common metric strings
+	subsystem             = "csi_sidecar"
+	labelCSIDriverName    = "driver_name"
+	labelCSIOperationName = "method_name"
+	labelGrpcStatusCode   = "grpc_status_code"
+	unknownCSIDriverName  = "unknown-driver"
+
+	// CSI Operation Latency with status code total - Histogram Metric
+	operationsLatencyMetricName = "operations_seconds"
+	operationsLatencyHelp       = "Container Storage Interface operation duration with gRPC error code status total"
+)
+
+var (
+	operationsLatencyBuckets = []float64{.1, .25, .5, 1, 2.5, 5, 10, 15, 25, 50, 120, 300, 600}
+)
+
+// CSIMetricsManager exposes functions for recording metrics for CSI operations.
+type CSIMetricsManager interface {
+	// GetRegistry() returns the metrics.KubeRegistry used by this metrics manager.
+	GetRegistry() metrics.KubeRegistry
+
+	// RecordMetrics must be called upon CSI Operation completion to record
+	// the operation's metric.
+	// operationName - Name of the CSI operation.
+	// operationErr - Error, if any, that resulted from execution of operation.
+	// operationDuration - time it took for the operation to complete
+	RecordMetrics(
+		operationName string,
+		operationErr error,
+		operationDuration time.Duration)
+
+	// SetDriverName is called to update the CSI driver name. This should be done
+	// as soon as possible, otherwise metrics recorded by this manager will be
+	// recorded with an "unknown-driver" driver_name.
+	// driverName - Name of the CSI driver against which this operation was executed.
+	SetDriverName(driverName string)
+
+	// StartMetricsEndpoint starts the metrics endpoint at the specified address/path
+	// for this metrics manager.
+	// If the metricsAddress is an empty string, this will be a no op.
+	StartMetricsEndpoint(metricsAddress, metricsPath string)
+}
+
+// NewCSIMetricsManager creates and registers metrics for for CSI Sidecars and
+// returns an object that can be used to trigger the metrics.
+// driverName - Name of the CSI driver against which this operation was executed.
+//              If unknown, leave empty, and use SetDriverName method to update later.
+func NewCSIMetricsManager(driverName string) CSIMetricsManager {
+	cmm := csiMetricsManager{
+		registry: metrics.NewKubeRegistry(),
+		csiOperationsLatencyMetric: metrics.NewHistogramVec(
+			&metrics.HistogramOpts{
+				Subsystem:      subsystem,
+				Name:           operationsLatencyMetricName,
+				Help:           operationsLatencyHelp,
+				Buckets:        operationsLatencyBuckets,
+				StabilityLevel: metrics.ALPHA,
+			},
+			[]string{labelCSIDriverName, labelCSIOperationName, labelGrpcStatusCode},
+		),
+	}
+
+	cmm.SetDriverName(driverName)
+	cmm.registerMetrics()
+	return &cmm
+}
+
+var _ CSIMetricsManager = &csiMetricsManager{}
+
+type csiMetricsManager struct {
+	registry                   metrics.KubeRegistry
+	driverName                 string
+	csiOperationsMetric        *metrics.CounterVec
+	csiOperationsLatencyMetric *metrics.HistogramVec
+}
+
+func (cmm *csiMetricsManager) GetRegistry() metrics.KubeRegistry {
+	return cmm.registry
+}
+
+// RecordMetrics must be called upon CSI Operation completion to record
+// the operation's metric.
+// operationName - Name of the CSI operation.
+// operationErr - Error, if any, that resulted from execution of operation.
+// operationDuration - time it took for the operation to complete
+func (cmm *csiMetricsManager) RecordMetrics(
+	operationName string,
+	operationErr error,
+	operationDuration time.Duration) {
+	cmm.csiOperationsLatencyMetric.WithLabelValues(
+		cmm.driverName, operationName, getErrorCode(operationErr)).Observe(operationDuration.Seconds())
+}
+
+// SetDriverName is called to update the CSI driver name. This should be done
+// as soon as possible, otherwise metrics recorded by this manager will be
+// recorded with an "unknown-driver" driver_name.
+func (cmm *csiMetricsManager) SetDriverName(driverName string) {
+	if driverName == "" {
+		cmm.driverName = unknownCSIDriverName
+	} else {
+		cmm.driverName = driverName
+	}
+}
+
+// StartMetricsEndpoint starts the metrics endpoint at the specified address/path
+// for this metrics manager  on a new go routine.
+// If the metricsAddress is an empty string, this will be a no op.
+func (cmm *csiMetricsManager) StartMetricsEndpoint(metricsAddress, metricsPath string) {
+	if metricsAddress == "" {
+		klog.Warningf("metrics endpoint will not be started because `metrics-address` was not specified.")
+		return
+	}
+
+	http.Handle(metricsPath, metrics.HandlerFor(
+		cmm.GetRegistry(),
+		metrics.HandlerOpts{
+			ErrorHandling: metrics.ContinueOnError}))
+
+	// Spawn a new go routine to listen on specified endpoint
+	go func() {
+		err := http.ListenAndServe(metricsAddress, nil)
+		if err != nil {
+			klog.Fatalf("Failed to start prometheus metrics endpoint on specified address (%q) and path (%q): %s", metricsAddress, metricsPath, err)
+		}
+	}()
+}
+
+// VerifyMetricsMatch is a helper function that verifies that the expected and
+// actual metrics are identical excluding metricToIgnore.
+// This method is only used by tests. Ideally it should be in the _test file,
+// but *_test.go files are compiled into the package only when running go test
+// for that package and this method is used by metrics_test as well as
+// connection_test. If there are more consumers in the future, we can consider
+// moving it to a new, standalone package.
+func VerifyMetricsMatch(expectedMetrics, actualMetrics string, metricToIgnore string) error {
+	gotScanner := bufio.NewScanner(strings.NewReader(strings.TrimSpace(actualMetrics)))
+	wantScanner := bufio.NewScanner(strings.NewReader(strings.TrimSpace(expectedMetrics)))
+	for gotScanner.Scan() {
+		wantScanner.Scan()
+		wantLine := strings.TrimSpace(wantScanner.Text())
+		gotLine := strings.TrimSpace(gotScanner.Text())
+		if wantLine != gotLine && (metricToIgnore == "" || !strings.HasPrefix(gotLine, metricToIgnore)) {
+			return fmt.Errorf("\r\nMetric Want: %q\r\nMetric Got:  %q\r\n", wantLine, gotLine)
+		}
+	}
+
+	return nil
+}
+
+func (cmm *csiMetricsManager) registerMetrics() {
+	cmm.registry.MustRegister(cmm.csiOperationsLatencyMetric)
+}
+
+func getErrorCode(err error) string {
+	if err == nil {
+		return codes.OK.String()
+	}
+
+	st, ok := status.FromError(err)
+	if !ok {
+		// This is not gRPC error. The operation must have failed before gRPC
+		// method was called, otherwise we would get gRPC error.
+		return "unknown-non-grpc"
+	}
+
+	return st.Code().String()
+}