*: add node selector

pkg/cluster/cluster.go

@@ -205,8 +205,8 @@ func (c *Cluster) migrateSeedMember() error {
 		initialCluster = append(initialCluster, fmt.Sprintf("%s=%s", m.Name, purl))
 	}
 
-	pod := k8sutil.MakeEtcdPod(m, initialCluster, c.name, "existing", "", c.spec.AntiAffinity, c.spec.HostNetwork)
-	pod = k8sutil.WithAddMemberInitContainer(pod, c.spec.Seed.MemberClientEndpoints, m.Name, mpurls)
+	pod := k8sutil.MakeEtcdPod(m, initialCluster, c.name, "existing", "", c.spec)
+	pod = k8sutil.PodWithAddMemberInitContainer(pod, c.spec.Seed.MemberClientEndpoints, m.Name, mpurls)
 
 	if err := k8sutil.CreateAndWaitPod(c.kclient, pod, m, c.namespace); err != nil {
 		return err
@@ -353,7 +353,7 @@ func (c *Cluster) createPodAndService(members etcdutil.MemberSet, m *etcdutil.Me
 	if state == "new" {
 		token = uuid.New()
 	}
-	pod := k8sutil.MakeEtcdPod(m, members.PeerURLPairs(), c.name, state, token, c.spec.AntiAffinity, c.spec.HostNetwork)
+	pod := k8sutil.MakeEtcdPod(m, members.PeerURLPairs(), c.name, state, token, c.spec)
 	if needRecovery {
 		k8sutil.AddRecoveryToPod(pod, c.name, m.Name, token)
 	}

pkg/spec/cluster.go

@@ -17,6 +17,12 @@ type ClusterSpec struct {
 	// cluster equal to the expected size.
 	// The vaild range of the size is from 1 to 7.
 	Size int `json:"size"`
+
+	// NodeSelector specifies a map of key-value pairs. For the pod to be eligible
+	// to run on a node, the node must have each of the indicated key-value pairs as
+	// labels.
+	NodeSelector map[string]string `json:"nodeSelector,omitempty"`
+
 	// AntiAffinity determines if the controller tries to avoid putting
 	// the etcd members in the same cluster onto the same node.
 	AntiAffinity bool `json:"antiAffinity"`

pkg/util/k8sutil/k8sutil.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/coreos/kube-etcd-controller/pkg/spec"
 	"github.com/coreos/kube-etcd-controller/pkg/util/etcdutil"
 	"k8s.io/kubernetes/pkg/api"
 	apierrors "k8s.io/kubernetes/pkg/api/errors"
@@ -75,7 +76,7 @@ func MakeBackupHostPort(clusterName string) string {
 	return fmt.Sprintf("%s:19999", makeBackupName(clusterName))
 }
 
-func WithAddMemberInitContainer(p *api.Pod, endpoints []string, name string, peerURLs []string) *api.Pod {
+func PodWithAddMemberInitContainer(p *api.Pod, endpoints []string, name string, peerURLs []string) *api.Pod {
 	spec := []api.Container{
 		{
 			Name:  "add-member",
@@ -97,6 +98,11 @@ func WithAddMemberInitContainer(p *api.Pod, endpoints []string, name string, pee
 	return p
 }
 
+func PodWithNodeSelector(p *api.Pod, ns map[string]string) *api.Pod {
+	p.Spec.NodeSelector = ns
+	return p
+}
+
 func makeBackupName(clusterName string) string {
 	return fmt.Sprintf("%s-backup-tool", clusterName)
 }
@@ -193,8 +199,7 @@ func AddRecoveryToPod(pod *api.Pod, clusterName, name, token string) {
 	pod.Annotations[k8sv1api.PodInitContainersAnnotationKey] = makeRestoreInitContainerSpec(MakeBackupHostPort(clusterName), name, token)
 }
 
-// todo: use a struct to replace the huge arg list.
-func MakeEtcdPod(m *etcdutil.Member, initialCluster []string, clusterName, state, token string, antiAffinity bool, hostNet bool) *api.Pod {
+func MakeEtcdPod(m *etcdutil.Member, initialCluster []string, clusterName, state, token string, cspec *spec.ClusterSpec) *api.Pod {
 	commands := []string{
 		"/usr/local/bin/etcd",
 		"--data-dir",
@@ -277,7 +282,7 @@ func MakeEtcdPod(m *etcdutil.Member, initialCluster []string, clusterName, state
 			},
 			RestartPolicy: api.RestartPolicyNever,
 			SecurityContext: &api.PodSecurityContext{
-				HostNetwork: hostNet,
+				HostNetwork: cspec.HostNetwork,
 			},
 			Volumes: []api.Volume{
 				{Name: "etcd-data", VolumeSource: api.VolumeSource{EmptyDir: &api.EmptyDirVolumeSource{}}},
@@ -285,7 +290,7 @@ func MakeEtcdPod(m *etcdutil.Member, initialCluster []string, clusterName, state
 		},
 	}
 
-	if !antiAffinity {
+	if !cspec.AntiAffinity {
 		return pod
 	}
 
@@ -311,6 +316,10 @@ func MakeEtcdPod(m *etcdutil.Member, initialCluster []string, clusterName, state
 
 	pod.Annotations[api.AffinityAnnotationKey] = string(affinityb)
 
+	if len(cspec.NodeSelector) != 0 {
+		pod = PodWithNodeSelector(pod, cspec.NodeSelector)
+	}
+
 	return pod
 }