Rename cli flag from label-metrics-allow-list to metric-labels-allowlist

This might be more clear on what the flag is doing. There were two ways
to spell allow-list / allowlist which it removes as well

Fixes: #1421

docs/cli-arguments.md

@@ -32,14 +32,14 @@ Usage of ./kube-state-metrics:
   -h, --help                              Print Help text
       --host string                       Host to expose metrics on. (default "0.0.0.0")
       --kubeconfig string                 Absolute path to the kubeconfig file
-      --labels-metric-allow-list string   Allows to pass a list of additional Kubernetes label keys that will be used in the resource' labels metric. By default the metric contains only name and namespace labels. To include additional labels provide a list of resource names in their plural form and Kubernetes label keys you would like to allow for them (Example: '=namespaces=[k8s-label-1,k8s-label-n,...],pods=[app],...)'
       --log_backtrace_at traceLocation    when logging hits line file:N, emit a stack trace (default :0)
       --log_dir string                    If non-empty, write log files in this directory
       --log_file string                   If non-empty, use this log file
       --log_file_max_size uint            Defines the maximum size a log file can grow to. Unit is megabytes. If the value is 0, the maximum file size is unlimited. (default 1800)
       --logtostderr                       log to standard error instead of files (default true)
       --metric-allowlist string           Comma-separated list of metrics to be exposed. This list comprises of exact metric names and/or regex patterns. The allowlist and denylist are mutually exclusive.
       --metric-denylist string            Comma-separated list of metrics not to be enabled. This list comprises of exact metric names and/or regex patterns. The allowlist and denylist are mutually exclusive.
+      --metric-labels-allowlist string    Comma-separated list of additional Kubernetes label keys that will be used in the resource' labels metric. By default the metric contains only name and namespace labels. To include additional labels provide a list of resource names in their plural form and Kubernetes label keys you would like to allow for them (Example: '=namespaces=[k8s-label-1,k8s-label-n,...],pods=[app],...)'
       --namespaces string                 Comma-separated list of namespaces to be enabled. Defaults to ""
       --one_output                        If true, only write logs to their native severity level (vs also writing to each lower severity level)
       --pod string                        Name of the pod that contains the kube-state-metrics container. When set, it is expected that --pod and --pod-namespace are both set. Most likely this should be passed via the downward API. This is used for auto-detecting sharding. If set, this has preference over statically configured sharding. This is experimental, it may be removed without notice.

pkg/options/options.go

@@ -88,6 +88,8 @@ func (o *Options) AddFlags() {
 	o.flags.Var(&o.Namespaces, "namespaces", fmt.Sprintf("Comma-separated list of namespaces to be enabled. Defaults to %q", &DefaultNamespaces))
 	o.flags.Var(&o.MetricAllowlist, "metric-allowlist", "Comma-separated list of metrics to be exposed. This list comprises of exact metric names and/or regex patterns. The allowlist and denylist are mutually exclusive.")
 	o.flags.Var(&o.MetricDenylist, "metric-denylist", "Comma-separated list of metrics not to be enabled. This list comprises of exact metric names and/or regex patterns. The allowlist and denylist are mutually exclusive.")
+	o.flags.Var(&o.LabelsAllowList, "metric-labels-allowlist", "Comma-separated list of additional Kubernetes label keys that will be used in the resource' labels metric. By default the metric contains only name and namespace labels. To include additional labels provide a list of resource names in their plural form and Kubernetes label keys you would like to allow for them (Example: '=namespaces=[k8s-label-1,k8s-label-n,...],pods=[app],...)'")
+
 	o.flags.Int32Var(&o.Shard, "shard", int32(0), "The instances shard nominal (zero indexed) within the total number of shards. (default 0)")
 	o.flags.IntVar(&o.TotalShards, "total-shards", 1, "The total number of shards. Sharding is disabled when total shards is set to 1.")
 
@@ -97,7 +99,6 @@ func (o *Options) AddFlags() {
 	o.flags.StringVar(&o.Namespace, "pod-namespace", "", "Name of the namespace of the pod specified by --pod. "+autoshardingNotice)
 	o.flags.BoolVarP(&o.Version, "version", "", false, "kube-state-metrics build version information")
 	o.flags.BoolVar(&o.EnableGZIPEncoding, "enable-gzip-encoding", false, "Gzip responses when requested by clients via 'Accept-Encoding: gzip' header.")
-	o.flags.Var(&o.LabelsAllowList, "labels-metric-allow-list", "Allows to pass a list of additional Kubernetes label keys that will be used in the resource' labels metric. By default the metric contains only name and namespace labels. To include additional labels provide a list of resource names in their plural form and Kubernetes label keys you would like to allow for them (Example: '=namespaces=[k8s-label-1,k8s-label-n,...],pods=[app],...)'")
 }
 
 // Parse parses the flag definitions from the argument list.