cluster: add option to specify busybox repository

pkg/apis/etcd/v1beta2/cluster.go

@@ -143,6 +143,14 @@ type PodPolicy struct {
 	// etcd cluster.
 	// The "etcd.version" annotation is reserved for the internal use of the etcd operator.
 	Annotations map[string]string `json:"annotations,omitempty"`
+
+	// busybox:latest uses uclibc which contains a bug that sometimes prevents name resolution
+	// More info: https://github.com/docker-library/busybox/issues/27
+	// busybox init container repository. default is busybox
+	BusyboxRepository string `json:"busyboxRepository,omitempty"`
+
+	// busybox init container version. defaults to 1.28.0-glibc
+	BusyboxVersion string `json:"busyboxVersion,omitempty"`
 }
 
 // TODO: move this to initializer

pkg/util/k8sutil/k8sutil.go

@@ -66,7 +66,9 @@ const (
 	// AnnotationScope annotation name for defining instance scope. Used for specifing cluster wide clusters.
 	AnnotationScope = "etcd.database.coreos.com/scope"
 	//AnnotationClusterWide annotation value for cluster wide clusters.
-	AnnotationClusterWide = "clusterwide"
+	AnnotationClusterWide    = "clusterwide"
+	defaultBusyboxRepository = "busybox"
+	defaultBusyboxVersion    = "1.28.0-glibc"
 )
 
 const TolerateUnreadyEndpointsAnnotation = "service.alpha.kubernetes.io/tolerate-unready-endpoints"
@@ -134,6 +136,21 @@ func ImageName(repo, version string) string {
 	return fmt.Sprintf("%s:v%v", repo, version)
 }
 
+func ImageNameBusybox(policy *api.PodPolicy) string {
+	// set defaults for busybox init container
+	repo := defaultBusyboxRepository
+	version := defaultBusyboxVersion
+
+	if policy != nil && len(policy.BusyboxRepository) > 0 {
+		repo = policy.BusyboxRepository
+	}
+
+	if policy != nil && len(policy.BusyboxVersion) > 0 {
+		version = policy.BusyboxVersion
+	}
+	return fmt.Sprintf("%s:%v", repo, version)
+}
+
 func PodWithNodeSelector(p *v1.Pod, ns map[string]string) *v1.Pod {
 	p.Spec.NodeSelector = ns
 	return p
@@ -355,7 +372,8 @@ func newEtcdPod(m *etcdutil.Member, initialCluster []string, clusterName, state,
 			InitContainers: []v1.Container{{
 				// busybox:latest uses uclibc which contains a bug that sometimes prevents name resolution
 				// More info: https://github.com/docker-library/busybox/issues/27
-				Image: "busybox:1.28.0-glibc",
+				//Image default: "busybox:1.28.0-glibc",
+				Image: ImageNameBusybox(cs.Pod),
 				Name:  "check-dns",
 				// In etcd 3.2, TLS listener will do a reverse-DNS lookup for pod IP -> hostname.
 				// If DNS entry is not warmed up, it will return empty result and peer connection will be rejected.

pkg/util/k8sutil/k8sutils_test.go

@@ -0,0 +1,51 @@
+// Copyright 2017 The etcd-operator 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 k8sutil
+
+import (
+	"fmt"
+	"testing"
+
+	api "github.com/coreos/etcd-operator/pkg/apis/etcd/v1beta2"
+)
+
+func TestDefaultBusyboxImageName(t *testing.T) {
+	policy := &api.PodPolicy{}
+	image := ImageNameBusybox(policy)
+	expected := fmt.Sprintf("%s:%v", defaultBusyboxRepository, defaultBusyboxVersion)
+	if image != expected {
+		t.Errorf("expect image=%s, get=%s", expected, image)
+	}
+}
+
+func TestDefaultNilBusyboxImageName(t *testing.T) {
+	image := ImageNameBusybox(nil)
+	expected := fmt.Sprintf("%s:%v", defaultBusyboxRepository, defaultBusyboxVersion)
+	if image != expected {
+		t.Errorf("expect image=%s, get=%s", expected, image)
+	}
+}
+
+func TestSetBusyboxImageName(t *testing.T) {
+	policy := &api.PodPolicy{
+		BusyboxVersion:    "1.3.2",
+		BusyboxRepository: "myRepo/busybox",
+	}
+	image := ImageNameBusybox(policy)
+	expected := fmt.Sprintf("%s:%v", "myRepo/busybox", "1.3.2")
+	if image != expected {
+		t.Errorf("expect image=%s, get=%s", expected, image)
+	}
+}