mapping some short label names to k8s well-known labels

pkg/manager/member/node.go

@@ -18,6 +18,15 @@ import (
 	corelisterv1 "k8s.io/client-go/listers/core/v1"
 )
 
+// a pre-defined mapping that mapping some short label name to k8s well-known labels.
+// PD depend on short label name to gain better performance.
+// See: https://github.com/pingcap/tidb-operator/issues/4678 for more details.
+var shortLabelNameToK8sLabel = map[string][]string{
+	"region": {corev1.LabelZoneRegionStable, corev1.LabelZoneRegion},
+	"zone":   {corev1.LabelZoneFailureDomainStable, corev1.LabelZoneFailureDomain},
+	"host":   {corev1.LabelHostname},
+}
+
 func getNodeLabels(nodeLister corelisterv1.NodeLister, nodeName string, storeLabels []string) (map[string]string, error) {
 	node, err := nodeLister.Get(nodeName)
 	if err != nil {
@@ -31,13 +40,14 @@ func getNodeLabels(nodeLister corelisterv1.NodeLister, nodeName string, storeLab
 			continue
 		}
 
-		// TODO after pd supports storeLabel containing slash character, these codes should be deleted
-		if storeLabel == "host" {
-			if host, found := ls[corev1.LabelHostname]; found {
-				labels[storeLabel] = host
+		if k8sLabels, ok := shortLabelNameToK8sLabel[storeLabel]; ok {
+			for _, name := range k8sLabels {
+				if value, ok := ls[name]; ok {
+					labels[storeLabel] = value
+					break
+				}
 			}
 		}
-
 	}
 	return labels, nil
 }

pkg/manager/member/node_test.go

@@ -0,0 +1,160 @@
+// Copyright 2018 PingCAP, Inc.
+//
+// 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,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package member
+
+import (
+	"testing"
+
+	. "github.com/onsi/gomega"
+	"github.com/pingcap/tidb-operator/pkg/controller"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func TestGetNodeLabels(t *testing.T) {
+	g := NewGomegaWithT(t)
+
+	type testcase struct {
+		nodeLabels  map[string]string
+		labels      []string
+		result      map[string]string
+		errExpectFn func(*GomegaWithT, error)
+	}
+
+	testNodeName := "test-node"
+
+	testFn := func(c *testcase, t *testing.T) {
+		fakeDeps := controller.NewFakeDependencies()
+		nodeIndexer := fakeDeps.KubeInformerFactory.Core().V1().Nodes().Informer().GetIndexer()
+
+		nodeIndexer.Add(&corev1.Node{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:   testNodeName,
+				Labels: c.nodeLabels,
+			},
+		})
+
+		res, err := getNodeLabels(fakeDeps.NodeLister, testNodeName, c.labels)
+		if c.errExpectFn != nil {
+			c.errExpectFn(g, err)
+		} else {
+			g.Expect(err).To(BeNil())
+			g.Expect(res).To(Equal(c.result))
+		}
+	}
+
+	tests := []*testcase{
+		{
+			nodeLabels: map[string]string{
+				"region": "us-west-1",
+				"zone":   "us-west-1a",
+				"host":   "172.16.0.1",
+			},
+			labels: []string{"region", "zone", "host"},
+			result: map[string]string{
+				"region": "us-west-1",
+				"zone":   "us-west-1a",
+				"host":   "172.16.0.1",
+			},
+		},
+		{
+			nodeLabels: map[string]string{
+				"kubernetes.io/os": "Linux",
+				"region":           "us-west-1",
+				"zone":             "us-west-1a",
+				"host":             "172.16.0.1",
+			},
+			labels: []string{"zone", "host"},
+			result: map[string]string{
+				"zone": "us-west-1a",
+				"host": "172.16.0.1",
+			},
+		},
+		{
+			nodeLabels: map[string]string{
+				"kubernetes.io/os": "Linux",
+				"region":           "us-west-1",
+				"zone":             "us-west-1a",
+			},
+			labels: []string{"region", "zone", "host"},
+			result: map[string]string{
+				"region": "us-west-1",
+				"zone":   "us-west-1a",
+			},
+		},
+		{
+			nodeLabels: map[string]string{
+				"kubernetes.io/os":              "Linux",
+				"topology.kubernetes.io/region": "us-west-1",
+				"topology.kubernetes.io/zone":   "us-west-1a",
+				"kubernetes.io/hostname":        "172.16.0.1",
+			},
+			labels: []string{"topology.kubernetes.io/region", "topology.kubernetes.io/zone", "kubernetes.io/hostname"},
+			result: map[string]string{
+				"topology.kubernetes.io/region": "us-west-1",
+				"topology.kubernetes.io/zone":   "us-west-1a",
+				"kubernetes.io/hostname":        "172.16.0.1",
+			},
+		},
+		{
+			nodeLabels: map[string]string{
+				"kubernetes.io/os":              "Linux",
+				"topology.kubernetes.io/region": "us-west-1",
+				"topology.kubernetes.io/zone":   "us-west-1a",
+				"kubernetes.io/hostname":        "172.16.0.1",
+			},
+			labels: []string{"region", "zone", "host"},
+			result: map[string]string{
+				"region": "us-west-1",
+				"zone":   "us-west-1a",
+				"host":   "172.16.0.1",
+			},
+		},
+		{
+			nodeLabels: map[string]string{
+				"kubernetes.io/os":                         "Linux",
+				"failure-domain.beta.kubernetes.io/region": "us-west-1",
+				"failure-domain.beta.kubernetes.io/zone":   "us-west-1a",
+				"kubernetes.io/hostname":                   "172.16.0.1",
+			},
+			labels: []string{"region", "zone", "host"},
+			result: map[string]string{
+				"region": "us-west-1",
+				"zone":   "us-west-1a",
+				"host":   "172.16.0.1",
+			},
+		},
+		{
+			nodeLabels: map[string]string{
+				"kubernetes.io/os":                         "Linux",
+				"failure-domain.beta.kubernetes.io/region": "us-west-1",
+				"failure-domain.beta.kubernetes.io/zone":   "us-west-1a",
+				"kubernetes.io/hostname":                   "172.16.0.1",
+				"region":                                   "test-region",
+				"zone":                                     "test-zone",
+				"host":                                     "test-host",
+			},
+			labels: []string{"region", "zone", "host"},
+			result: map[string]string{
+				"region": "test-region",
+				"zone":   "test-zone",
+				"host":   "test-host",
+			},
+		},
+	}
+
+	for _, test := range tests {
+		testFn(test, t)
+	}
+}