Updated check if a node is master.

pkg/util/system/BUILD

@@ -16,3 +16,11 @@ go_library(
     tags = ["automanaged"],
     deps = ["//pkg/api:go_default_library"],
 )
+
+go_test(
+    name = "go_default_test",
+    srcs = ["system_utils_test.go"],
+    library = "go_default_library",
+    tags = ["automanaged"],
+    deps = ["//pkg/api:go_default_library"],
+)

pkg/util/system/system_utils.go

@@ -17,12 +17,13 @@ limitations under the License.
 package system
 
 import (
-	"strings"
+	"regexp"
 
 	"k8s.io/kubernetes/pkg/api"
 )
 
 // TODO: find a better way of figuring out if given node is a registered master.
 func IsMasterNode(node *api.Node) bool {
-	return strings.HasSuffix(node.Name, "master")
+	r := regexp.MustCompile("master(-...)?$")
+	return r.MatchString(node.Name)
 }

pkg/util/system/system_utils_test.go

+/*
+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 system
+
+import (
+	"testing"
+
+	"k8s.io/kubernetes/pkg/api"
+)
+
+func TestIsMasterNode(t *testing.T) {
+	testCases := []struct {
+		input  string
+		result bool
+	}{
+		{"foo-master", true},
+		{"foo-master-", false},
+		{"foo-master-a", false},
+		{"foo-master-ab", false},
+		{"foo-master-abc", true},
+		{"foo-master-abdc", false},
+		{"foo-bar", false},
+	}
+
+	for _, tc := range testCases {
+		node := api.Node{ObjectMeta: api.ObjectMeta{Name: tc.input}}
+		res := IsMasterNode(&node)
+		if res != tc.result {
+			t.Errorf("case \"%s\": expected %t, got %t", tc.input, tc.result, res)
+		}
+	}
+}