Refactoring

README.md

@@ -239,7 +239,7 @@ The downside of using an auto-sharded setup comes from the rollout strategy supp
 ### Daemonset sharding for pod metrics
 
 For pod metrics, they can be sharded per node with the following flag:
-* `--nodename`
+* `--node`
 
 Each kube-state-metrics pod uses FieldSelector (spec.nodeName) to watch/list pod metrics only on the same node.
 
@@ -255,7 +255,7 @@ spec:
         name: kube-state-metrics
         args:
         - --resource=pods
-        - --nodename=$(NODE_NAME)
+        - --node=$(NODE_NAME)
         env:
         - name: NODE_NAME
           valueFrom:

docs/cli-arguments.md

@@ -46,7 +46,7 @@ Usage of ./kube-state-metrics:
       --metric-opt-in-list string                  Comma-separated list of metrics which are opt-in and not enabled by default. This is in addition to the metric allow- and denylists
       --namespaces string                          Comma-separated list of namespaces to be enabled. Defaults to ""
       --namespaces-denylist string                 Comma-separated list of namespaces not to be enabled. If namespaces and namespaces-denylist are both set, only namespaces that are excluded in namespaces-denylist will be used.
-      --nodename string                            Name of the node that contains the kube-state-metrics pod, only available for resources (pod metrics) that support spec.nodeName fieldSelector. Each kube-state-metrics pod will only exposes metrics related to this node.
+      --node string                                Name of the node that contains the kube-state-metrics pod. Most likely it should be passed via the downward API. This is used for daemonset sharding. Only available for resources (pod metrics) that support spec.nodeName fieldSelector. This is experimental.
       --one_output                                 If true, only write logs to their native severity level (vs also writing to each lower severity level; no effect when -logtostderr=true)
       --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.
       --pod-namespace string                       Name of the namespace of the pod specified by --pod. 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/app/server.go

@@ -106,8 +106,8 @@ func RunKubeStateMetrics(ctx context.Context, opts *options.Options, factories .
 
 	namespaces := opts.Namespaces.GetNamespaces()
 	nsFieldSelector := namespaces.GetExcludeNSFieldSelector(opts.NamespacesDenylist)
-	nodeNameFieldSelector := opts.NodeName.GetNodeNameFieldSelector()
-	merged, err := storeBuilder.MergeFieldSelectors([]string{nsFieldSelector, nodeNameFieldSelector})
+	nodeFieldSelector := opts.Node.GetNodeFieldSelector()
+	merged, err := storeBuilder.MergeFieldSelectors([]string{nsFieldSelector, nodeFieldSelector})
 	if err != nil {
 		return err
 	}

pkg/options/options.go

@@ -39,7 +39,7 @@ type Options struct {
 	Resources            ResourceSet
 	Namespaces           NamespaceList
 	NamespacesDenylist   NamespaceList
-	NodeName             NodeNameType
+	Node                 NodeType
 	Shard                int32
 	TotalShards          int
 	Pod                  string
@@ -104,7 +104,6 @@ func (o *Options) AddFlags() {
 	o.flags.Var(&o.Resources, "resources", fmt.Sprintf("Comma-separated list of Resources to be enabled. Defaults to %q", &DefaultResources))
 	o.flags.Var(&o.Namespaces, "namespaces", fmt.Sprintf("Comma-separated list of namespaces to be enabled. Defaults to %q", &DefaultNamespaces))
 	o.flags.Var(&o.NamespacesDenylist, "namespaces-denylist", "Comma-separated list of namespaces not to be enabled. If namespaces and namespaces-denylist are both set, only namespaces that are excluded in namespaces-denylist will be used.")
-	o.flags.StringVar((*string)(&o.NodeName), "nodename", "", "Name of the node that contains the kube-state-metrics pod, only available for resources (pod metrics) that support spec.nodeName fieldSelector. Each kube-state-metrics pod will only exposes metrics related to this node.")
 	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.MetricOptInList, "metric-opt-in-list", "Comma-separated list of metrics which are opt-in and not enabled by default. This is in addition to the metric allow- and denylists")
@@ -113,6 +112,8 @@ func (o *Options) AddFlags() {
 	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.")
 
+	o.flags.StringVar((*string)(&o.Node), "node", "", "Name of the node that contains the kube-state-metrics pod. Most likely it should be passed via the downward API. This is used for daemonset sharding. Only available for resources (pod metrics) that support spec.nodeName fieldSelector. This is experimental.")
+
 	autoshardingNotice := "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."
 
 	o.flags.StringVar(&o.Pod, "pod", "", "Name of the pod that contains the kube-state-metrics container. "+autoshardingNotice)
@@ -138,12 +139,12 @@ func (o *Options) Usage() {
 // Validate validates arguments
 func (o *Options) Validate() error {
 	shardableResource := "pods"
-	if o.NodeName == "" {
+	if o.Node == "" {
 		return nil
 	}
 	for _, x := range o.Resources.AsSlice() {
 		if x != shardableResource {
-			return fmt.Errorf("Resource %s can't be sharding by field selector spec.nodeName", x)
+			return fmt.Errorf("Resource %s can't be sharded by field selector spec.nodeName", x)
 		}
 	}
 	return nil

pkg/options/types.go

@@ -104,11 +104,11 @@ func (r *ResourceSet) Type() string {
 	return "string"
 }
 
-// NodeNameType represents a nodeName to query from.
-type NodeNameType string
+// NodeType represents a nodeName to query from.
+type NodeType string
 
-// GetNodeNameFieldSelector returns a nodename field selector.
-func (n *NodeNameType) GetNodeNameFieldSelector() string {
+// GetNodeFieldSelector returns a nodename field selector.
+func (n *NodeType) GetNodeFieldSelector() string {
 	if string(*n) != "" {
 		return fields.OneTermEqualSelector("spec.nodeName", string(*n)).String()
 	}

pkg/options/types_test.go

@@ -155,27 +155,27 @@ func TestNamespaceList_ExcludeNamespacesFieldSelector(t *testing.T) {
 	}
 }
 
-func TestNodeNameFieldSelector(t *testing.T) {
+func TestNodeFieldSelector(t *testing.T) {
 	tests := []struct {
-		Desc     string
-		NodeName NodeNameType
-		Wanted   string
+		Desc   string
+		Node   NodeType
+		Wanted string
 	}{
 		{
-			Desc:     "empty node name",
-			NodeName: "",
-			Wanted:   "",
+			Desc:   "empty node name",
+			Node:   "",
+			Wanted: "",
 		},
 		{
-			Desc:     "with node name",
-			NodeName: "k8s-node-1",
-			Wanted:   "spec.nodeName=k8s-node-1",
+			Desc:   "with node name",
+			Node:   "k8s-node-1",
+			Wanted: "spec.nodeName=k8s-node-1",
 		},
 	}
 
 	for _, test := range tests {
-		node := test.NodeName
-		actual := node.GetNodeNameFieldSelector()
+		node := test.Node
+		actual := node.GetNodeFieldSelector()
 		if !reflect.DeepEqual(actual, test.Wanted) {
 			t.Errorf("Test error for Desc: %s. Want: %+v. Got: %+v.", test.Desc, test.Wanted, actual)
 		}
@@ -187,49 +187,49 @@ func TestMergeFieldSelectors(t *testing.T) {
 		Desc             string
 		Namespaces       NamespaceList
 		DeniedNamespaces NamespaceList
-		NodeName         NodeNameType
+		Node             NodeType
 		Wanted           string
 	}{
 		{
 			Desc:             "empty DeniedNamespaces",
 			Namespaces:       NamespaceList{"default", "kube-system"},
 			DeniedNamespaces: NamespaceList{},
-			NodeName:         "",
+			Node:             "",
 			Wanted:           "",
 		},
 		{
 			Desc:             "all DeniedNamespaces",
 			Namespaces:       DefaultNamespaces,
 			DeniedNamespaces: NamespaceList{"some-system"},
-			NodeName:         "",
+			Node:             "",
 			Wanted:           "metadata.namespace!=some-system",
 		},
 		{
 			Desc:             "general case",
 			Namespaces:       DefaultNamespaces,
 			DeniedNamespaces: NamespaceList{"case1-system", "case2-system"},
-			NodeName:         "",
+			Node:             "",
 			Wanted:           "metadata.namespace!=case1-system,metadata.namespace!=case2-system",
 		},
 		{
 			Desc:             "empty DeniedNamespaces",
 			Namespaces:       NamespaceList{"default", "kube-system"},
 			DeniedNamespaces: NamespaceList{},
-			NodeName:         "k8s-node-1",
+			Node:             "k8s-node-1",
 			Wanted:           "spec.nodeName=k8s-node-1",
 		},
 		{
 			Desc:             "all DeniedNamespaces",
 			Namespaces:       DefaultNamespaces,
 			DeniedNamespaces: NamespaceList{"some-system"},
-			NodeName:         "k8s-node-1",
+			Node:             "k8s-node-1",
 			Wanted:           "metadata.namespace!=some-system,spec.nodeName=k8s-node-1",
 		},
 		{
 			Desc:             "general case",
 			Namespaces:       DefaultNamespaces,
 			DeniedNamespaces: NamespaceList{"case1-system", "case2-system"},
-			NodeName:         "k8s-node-1",
+			Node:             "k8s-node-1",
 			Wanted:           "metadata.namespace!=case1-system,metadata.namespace!=case2-system,spec.nodeName=k8s-node-1",
 		},
 	}
@@ -238,7 +238,7 @@ func TestMergeFieldSelectors(t *testing.T) {
 		ns := test.Namespaces
 		deniedNS := test.DeniedNamespaces
 		selector1 := ns.GetExcludeNSFieldSelector(deniedNS)
-		selector2 := test.NodeName.GetNodeNameFieldSelector()
+		selector2 := test.Node.GetNodeFieldSelector()
 		actual, err := MergeFieldSelectors([]string{selector1, selector2})
 		if err != nil {
 			t.Errorf("Test error for Desc: %s. Can't merge field selector %v.", test.Desc, err)