diff --git a/cmd/integration/integration.go b/cmd/integration/integration.go index 1082bcaecb..03d6b753f2 100644 --- a/cmd/integration/integration.go +++ b/cmd/integration/integration.go @@ -241,7 +241,7 @@ func startComponents(firstManifestURL, secondManifestURL string) (string, string 3*time.Second, /* NodeStatusUpdateFrequency */ 10*time.Second, /* SyncFrequency */ 40, /* MaxPods */ - cm) + cm, net.ParseIP("127.0.0.1")) kubeletapp.RunKubelet(kcfg) // Kubelet (machine) @@ -274,7 +274,8 @@ func startComponents(firstManifestURL, secondManifestURL string) (string, string 10*time.Second, /* SyncFrequency */ 40, /* MaxPods */ - cm) + cm, + net.ParseIP("127.0.0.1")) kubeletapp.RunKubelet(kcfg) return apiServer.URL, configFilePath diff --git a/cmd/kubelet/app/server.go b/cmd/kubelet/app/server.go index 1196159ce4..226f7a6f69 100644 --- a/cmd/kubelet/app/server.go +++ b/cmd/kubelet/app/server.go @@ -703,7 +703,7 @@ func SimpleKubelet(client *client.Client, osInterface kubecontainer.OSInterface, fileCheckFrequency, httpCheckFrequency, minimumGCAge, nodeStatusUpdateFrequency, syncFrequency time.Duration, maxPods int, - containerManager cm.ContainerManager) *KubeletConfig { + containerManager cm.ContainerManager, clusterDNS net.IP) *KubeletConfig { imageGCPolicy := kubelet.ImageGCPolicy{ HighThresholdPercent: 90, LowThresholdPercent: 80, @@ -718,6 +718,7 @@ func SimpleKubelet(client *client.Client, CAdvisorInterface: cadvisorInterface, CgroupRoot: "", Cloud: cloud, + ClusterDNS: clusterDNS, ConfigFile: configFilePath, ContainerManager: containerManager, ContainerRuntime: "docker", diff --git a/pkg/kubelet/kubelet.go b/pkg/kubelet/kubelet.go index 61cb2a746c..0c0d94d0b0 100644 --- a/pkg/kubelet/kubelet.go +++ b/pkg/kubelet/kubelet.go @@ -1465,7 +1465,7 @@ func (kl *Kubelet) podFieldSelectorRuntimeValue(fs *api.ObjectFieldSelector, pod // domains of the cluster. func (kl *Kubelet) getClusterDNS(pod *api.Pod) ([]string, []string, error) { var hostDNS, hostSearch []string - // Get host DNS settings and append them to cluster DNS settings. + // Get host DNS settings if kl.resolverConfig != "" { f, err := os.Open(kl.resolverConfig) if err != nil { @@ -1495,9 +1495,17 @@ func (kl *Kubelet) getClusterDNS(pod *api.Pod) ([]string, []string, error) { var dns, dnsSearch []string if kl.clusterDNS != nil { - dns = append([]string{kl.clusterDNS.String()}, hostDNS...) + // for a pod with DNSClusterFirst policy, the cluster DNS server is the only nameserver configured for + // the pod. The cluster DNS server itself will forward queries to other nameservers that is configured to use, + // in case the cluster DNS server cannot resolve the DNS query itself + dns = []string{kl.clusterDNS.String()} } else { - dns = hostDNS + // clusterDNS is not known. + // pod with ClusterDNSFirst Policy cannot be created + kl.recorder.Eventf(pod, api.EventTypeWarning, "MissingClusterDNS", "kubelet does not have ClusterDNS IP configured and cannot create Pod using %q policy", pod.Spec.DNSPolicy) + log := fmt.Sprintf("kubelet does not have ClusterDNS IP configured and cannot create Pod using %q policy. pod:%q", pod.Spec.DNSPolicy, kubecontainer.GetPodFullName(pod)) + kl.recorder.Eventf(kl.nodeRef, api.EventTypeWarning, "MissingClusterDNS", log) + return nil, nil, fmt.Errorf(log) } if kl.clusterDomain != "" { nsSvcDomain := fmt.Sprintf("%s.svc.%s", pod.Namespace, kl.clusterDomain) diff --git a/pkg/kubelet/kubelet_test.go b/pkg/kubelet/kubelet_test.go index 6095ba384d..947ea2f5b9 100644 --- a/pkg/kubelet/kubelet_test.go +++ b/pkg/kubelet/kubelet_test.go @@ -1019,8 +1019,8 @@ func TestDNSConfigurationParams(t *testing.T) { } } t.Logf("nameservers %+v", options[1].DNS) - if len(options[0].DNS) != len(options[1].DNS)+1 { - t.Errorf("expected prepend of cluster nameserver, got %+v", options[0].DNS) + if len(options[0].DNS) != 1 { + t.Errorf("expected cluster nameserver only, got %+v", options[0].DNS) } else if options[0].DNS[0] != clusterNS { t.Errorf("expected nameserver %s, got %v", clusterNS, options[0].DNS[0]) } diff --git a/pkg/kubemark/hollow_kubelet.go b/pkg/kubemark/hollow_kubelet.go index c37b0cb83b..aa04c72f31 100644 --- a/pkg/kubemark/hollow_kubelet.go +++ b/pkg/kubemark/hollow_kubelet.go @@ -72,6 +72,7 @@ func NewHollowKubelet( 10*time.Second, /* SyncFrequency */ 40, /* MaxPods */ containerManager, + nil, ), } }