Fix --nodeName= doesn't select unscheduable pods

pods

Author: CatherineF-dev

README.md

@@ -282,7 +282,7 @@ spec:
               fieldPath: spec.nodeName
 ```
 
-To track metrics for unassigned pods, you need to add an additional deployment and set `--node=""`, as shown in the following example:
+To track metrics for unassigned pods, you need to add an additional deployment and set `--node=`, as shown in the following example:
 
 ```
 apiVersion: apps/v1

README.md.tpl

@@ -283,7 +283,7 @@ spec:
               fieldPath: spec.nodeName
 ```
 
-To track metrics for unassigned pods, you need to add an additional deployment and set `--node=""`, as shown in the following example:
+To track metrics for unassigned pods, you need to add an additional deployment and set `--node=`, as shown in the following example:
 
 ```
 apiVersion: apps/v1

examples/daemonsetsharding/deployment-no-node-pods-service.yaml

@@ -0,0 +1,20 @@
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app.kubernetes.io/component: exporter
+    app.kubernetes.io/name: kube-state-metrics-no-node-pods
+    app.kubernetes.io/version: 2.12.0
+  name: kube-state-metrics-no-node-pods
+  namespace: kube-system
+spec:
+  clusterIP: None
+  ports:
+  - name: http-metrics
+    port: 8080
+    targetPort: http-metrics
+  - name: telemetry
+    port: 8081
+    targetPort: telemetry
+  selector:
+    app.kubernetes.io/name: kube-state-metrics-no-node-pods

examples/daemonsetsharding/deployment-no-node-pods.yaml

@@ -3,20 +3,20 @@ kind: Deployment
 metadata:
   labels:
     app.kubernetes.io/component: exporter
-    app.kubernetes.io/name: kube-state-metrics-pods
+    app.kubernetes.io/name: kube-state-metrics-no-node-pods
     app.kubernetes.io/version: 2.13.0
-  name: kube-state-metrics-pods
+  name: kube-state-metrics-no-node-pods
   namespace: kube-system
 spec:
   replicas: 1
   selector:
     matchLabels:
-      app.kubernetes.io/name: kube-state-metrics
+      app.kubernetes.io/name: kube-state-metrics-no-node-pods
   template:
     metadata:
       labels:
         app.kubernetes.io/component: exporter
-        app.kubernetes.io/name: kube-state-metrics
+        app.kubernetes.io/name: kube-state-metrics-no-node-pods
         app.kubernetes.io/version: 2.13.0
     spec:
       automountServiceAccountToken: true
@@ -31,7 +31,7 @@ spec:
             port: http-metrics
           initialDelaySeconds: 5
           timeoutSeconds: 5
-        name: kube-state-metrics
+        name: kube-state-metrics-no-node-pods
         ports:
         - containerPort: 8080
           name: http-metrics

jsonnet/kube-state-metrics/kube-state-metrics.libsonnet

@@ -379,16 +379,25 @@
           '--resources=pods',
           '--node=""',
         ],
+        name: shardksmname,
       };
-      local shardksmname = ksm.name + "-pods";
+      local shardksmname = ksm.name + "-no-node-pods";
       std.mergePatch(ksm.deployment,
         {
           metadata: {
             name: shardksmname,
             labels: {'app.kubernetes.io/name': shardksmname}
           },
           spec: {
+            selector{
+              matchLabels: {app.kubernetes.io/name': shardksmname}
+            }
             template: {
+              metadata: {
+                labels: {
+                  app.kubernetes.io/name': shardksmname
+                }
+              }
               spec: {
                 containers: [c],
               },
@@ -397,6 +406,27 @@
         },
       ),
 
+    deploymentNoNodePodsService:
+      local c = ksm.deployment.spec.template.spec.containers[0] {
+        args: [
+          '--resources=pods',
+          '--node=""',
+        ],
+      };
+      local shardksmname = ksm.name + "-no-node-pods";
+      std.mergePatch(ksm.service,
+        {
+          metadata: {
+            name: shardksmname,
+            labels: {'app.kubernetes.io/name': shardksmname}
+          },
+          spec: {
+            selector: {
+              'app.kubernetes.io/name': shardksmname
+            }
+          }
+        }
+      ),
     daemonset:
       // extending the default container from above
       local c0 = ksm.deployment.spec.template.spec.containers[0] {

pkg/options/types.go

@@ -18,7 +18,6 @@ package options
 
 import (
 	"errors"
-	"regexp"
 	"sort"
 	"strings"
 
@@ -141,15 +140,18 @@ func (n *NodeType) Type() string {
 
 // GetNodeFieldSelector returns a nodename field selector.
 func (n *NodeType) GetNodeFieldSelector() string {
-	if nil == n || len(*n) == 0 {
+	if nil == n {
 		klog.InfoS("Using node type is nil")
 		return EmptyFieldSelector()
 	}
-	pattern := "[^a-zA-Z0-9_,-]+"
-	re := regexp.MustCompile(pattern)
-	result := re.ReplaceAllString(n.String(), "")
-	klog.InfoS("Using node type", "node", result)
-	return fields.OneTermEqualSelector("spec.nodeName", result).String()
+	nodeName := n.String()
+	// `--node=""` find pods without node name assigned which uses fieldselector spec.nodeName=""
+	klog.InfoS("Using node name", nodeName)
+	if nodeName == "" {
+		klog.InfoS("Using spec.nodeName= to select unscheduable pods without node")
+		return "spec.nodeName="
+	}
+	return fields.OneTermEqualSelector("spec.nodeName", nodeName).String()
 
 }