Adding common flags to the standard flags package

Author: DerekFrank

standardflags/flags.go

@@ -0,0 +1,87 @@
+/*
+Copyright 2025 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 standardflags
+
+import (
+	"flag"
+	"fmt"
+	"time"
+	"strings"
+)
+
+
+type SidecarConfiguration struct {
+	ShowVersion bool
+
+	Master     string
+	KubeConfig string
+	CSIAddress string
+	Resync     time.Duration
+
+	RetryIntervalStart time.Duration
+	RetryIntervalMax   time.Duration
+
+	LeaderElection              bool
+	LeaderElectionNamespace     string
+	LeaderElectionLeaseDuration time.Duration
+	LeaderElectionRenewDeadline time.Duration
+	LeaderElectionRetryPeriod   time.Duration
+	LeaderElectionLabels		stringMap
+
+	KubeAPIQPS   float64
+	KubeAPIBurst int
+}
+
+var Configuration = SidecarConfiguration{}
+
+func RegisterCommonFlags(flags *flag.FlagSet) {
+	flags.BoolVar(&Configuration.ShowVersion, "version", false, "Show version.")
+	flags.StringVar(&Configuration.Master, "master", "", "Master URL to build a client config from. Either this or kubeconfig needs to be set if the provisioner is being run out of cluster.")
+	flags.StringVar(&Configuration.KubeConfig, "kubeconfig", "", "Absolute path to the kubeconfig file. Required only when running out of cluster.")
+	flags.StringVar(&Configuration.CSIAddress, "csi-address", "/run/csi/socket", "The gRPC endpoint for Target CSI Volume.")
+	flags.DurationVar(&Configuration.RetryIntervalStart, "retry-interval-start", time.Second, "Initial retry interval of failed create volume or deletion. It doubles with each failure, up to retry-interval-max.")
+	flags.DurationVar(&Configuration.RetryIntervalMax, "retry-interval-max", 5*time.Minute, "Maximum retry interval of failed create volume or deletion.")
+	flags.BoolVar(&Configuration.LeaderElection, "leader-election", false, "Enable leader election.")
+	flags.StringVar(&Configuration.LeaderElectionNamespace, "leader-election-namespace", "", "Namespace where the leader election resource lives. Defaults to the pod namespace if not set.")
+	flags.DurationVar(&Configuration.LeaderElectionLeaseDuration, "leader-election-lease-duration", 15*time.Second, "Duration, in seconds, that non-leader candidates will wait to force acquire leadership. Defaults to 15 seconds.")
+	flags.DurationVar(&Configuration.LeaderElectionRenewDeadline, "leader-election-renew-deadline", 10*time.Second, "Duration, in seconds, that the acting leader will retry refreshing leadership before giving up. Defaults to 10 seconds.")
+	flags.DurationVar(&Configuration.LeaderElectionRetryPeriod, "leader-election-retry-period", 5*time.Second, "Duration, in seconds, the LeaderElector clients should wait between tries of actions. Defaults to 5 seconds.")
+	flags.Var(&Configuration.LeaderElectionLabels, "leader-election-labels", "List of labels to add to lease when given replica becomes leader. Formatted as a comma seperated list of key:value labels. Example: 'my-label:my-value,my-second-label:my-second-value'")
+	flags.Float64Var(&Configuration.KubeAPIQPS, "kube-api-qps", 5, "QPS to use while communicating with the kubernetes apiserver. Defaults to 5.0.")
+	flags.IntVar(&Configuration.KubeAPIBurst, "kube-api-burst", 10, "Burst to use while communicating with the kubernetes apiserver. Defaults to 10.")
+}
+
+
+type stringMap map[string]string
+
+func (sm *stringMap) String() string {
+	return fmt.Sprintf("%s", *sm)
+}
+
+func (sm *stringMap) Set(value string) error {
+	outMap := *sm
+	items := strings.Split(value, ",")
+	for _, i := range items {
+		label := strings.Split(i, ":")
+		if len(label) != 2 {
+			return fmt.Errorf("malformed item in list of labels", "arg", i)
+		}
+		outMap[label[0]] = label[1]
+	}
+	return nil
+}
+