Part 1 of pr #33763: cleanup CheckServiceAffinity in preparation for

predicate injection support, Update metadata struct

plugin/pkg/scheduler/algorithm/predicates/utils_test.go

@@ -0,0 +1,65 @@
+/*
+Copyright 2016 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 predicates
+
+import (
+	"fmt"
+
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/labels"
+)
+
+// ExampleUtils is a https://blog.golang.org/examples styled unit test.
+func ExampleFindLabelsInSet() {
+	labelSubset := labels.Set{}
+	labelSubset["label1"] = "value1"
+	labelSubset["label2"] = "value2"
+	// Lets make believe that these pods are on the cluster.
+	// Utility functions will inspect their labels, filter them, and so on.
+	nsPods := []*api.Pod{
+		{
+			ObjectMeta: api.ObjectMeta{
+				Name:      "pod1",
+				Namespace: "ns1",
+				Labels: map[string]string{
+					"label1": "wontSeeThis",
+					"label2": "wontSeeThis",
+					"label3": "will_see_this",
+				},
+			},
+		}, // first pod which will be used via the utilities
+		{
+			ObjectMeta: api.ObjectMeta{
+				Name:      "pod2",
+				Namespace: "ns1",
+			},
+		},
+
+		{}, // a third pod which will have no effect on anything.
+	}
+	fmt.Println(FindLabelsInSet([]string{"label1", "label2", "label3"}, nsPods[0].ObjectMeta.Labels)["label3"])
+	AddUnsetLabelsToMap(labelSubset, []string{"label1", "label2", "label3"}, nsPods[0].ObjectMeta.Labels)
+	fmt.Println(labelSubset)
+
+	for _, pod := range FilterPodsByNamespace(nsPods, "ns1") {
+		fmt.Print(pod.Name, ",")
+	}
+	// Output:
+	// will_see_this
+	// label1=value1,label2=value2,label3=will_see_this
+	// pod1,pod2,
+}