Add metric for credential provider

Signed-off-by: Aditi Sharma <adi.sky17@gmail.com>

pkg/credentialprovider/plugin/metrics.go

@@ -0,0 +1,64 @@
+/*
+Copyright 2021 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 plugin
+
+import (
+	"sync"
+
+	"k8s.io/component-base/metrics"
+	"k8s.io/component-base/metrics/legacyregistry"
+)
+
+const (
+	kubeletCredentialProviderPluginErrorsKey   = "kubelet_credential_provider_plugin_errors"
+	kubeletCredentialProviderPluginDurationKey = "kubelet_credential_provider_plugin_duration"
+	KubeletSubsystem                           = "kubelet"
+)
+
+var (
+	registerOnce sync.Once
+
+	kubeletCredentialProviderPluginErrors = metrics.NewCounterVec(
+		&metrics.CounterOpts{
+			Subsystem:      KubeletSubsystem,
+			Name:           kubeletCredentialProviderPluginErrorsKey,
+			Help:           "Number of errors from credential provider plugin",
+			StabilityLevel: metrics.ALPHA,
+		},
+		[]string{"plugin_name"},
+	)
+
+	kubeletCredentialProviderPluginDuration = metrics.NewHistogramVec(
+		&metrics.HistogramOpts{
+			Subsystem:      KubeletSubsystem,
+			Name:           kubeletCredentialProviderPluginDurationKey,
+			Help:           "Duration of execution in seconds for credential provider plugin",
+			Buckets:        metrics.DefBuckets,
+			StabilityLevel: metrics.ALPHA,
+		},
+		[]string{"plugin_name"},
+	)
+)
+
+// registerMetrics registers credential provider metrics.
+func registerMetrics() {
+	registerOnce.Do(func() {
+		legacyregistry.MustRegister(kubeletCredentialProviderPluginErrors)
+		legacyregistry.MustRegister(kubeletCredentialProviderPluginDuration)
+
+	})
+}

pkg/credentialprovider/plugin/plugin.go

@@ -86,6 +86,9 @@ func RegisterCredentialProviderPlugins(pluginConfigFile, pluginBinDir string) er
 		return fmt.Errorf("failed to validate credential provider config: %v", errs.ToAggregate())
 	}
 
+	// Register metrics for credential providers
+	registerMetrics()
+
 	for _, provider := range credentialProviderConfig.Providers {
 		pluginBin := filepath.Join(pluginBinDir, provider.Name)
 		if _, err := os.Stat(pluginBin); err != nil {
@@ -398,14 +401,8 @@ func (e *execPlugin) ExecPlugin(ctx context.Context, image string) (*credentialp
 	// also, this behaviour is inline with Credential Provider Config spec
 	cmd.Env = mergeEnvVars(e.environ(), configEnvVars)
 
-	err = cmd.Run()
-	if ctx.Err() != nil {
-		return nil, fmt.Errorf("error execing credential provider plugin %s for image %s: %w", e.name, image, ctx.Err())
-	}
-
-	if err != nil {
-		klog.V(2).Infof("Error execing credential provider plugin, stderr: %v", stderr.String())
-		return nil, fmt.Errorf("error execing credential provider plugin %s for image %s: %w", e.name, image, err)
+	if err = e.runPlugin(ctx, cmd, image); err != nil {
+		return nil, err
 	}
 
 	data = stdout.Bytes()
@@ -428,6 +425,22 @@ func (e *execPlugin) ExecPlugin(ctx context.Context, image string) (*credentialp
 	return response, nil
 }
 
+func (e *execPlugin) runPlugin(ctx context.Context, cmd *exec.Cmd, image string) error {
+	startTime := time.Now()
+	defer kubeletCredentialProviderPluginDuration.WithLabelValues(e.name).Observe(time.Since(startTime).Seconds())
+
+	err := cmd.Run()
+	if ctx.Err() != nil {
+		kubeletCredentialProviderPluginErrors.WithLabelValues(e.name).Inc()
+		return fmt.Errorf("error execing credential provider plugin %s for image %s: %w", e.name, image, ctx.Err())
+	}
+	if err != nil {
+		kubeletCredentialProviderPluginErrors.WithLabelValues(e.name).Inc()
+		return fmt.Errorf("error execing credential provider plugin %s for image %s: %w", e.name, image, err)
+	}
+	return nil
+}
+
 // encodeRequest encodes the internal CredentialProviderRequest type into the v1alpha1 version in json
 func (e *execPlugin) encodeRequest(request *credentialproviderapi.CredentialProviderRequest) ([]byte, error) {
 	data, err := runtime.Encode(e.encoder, request)