Change:
Looks like some kubelet unit tests perform a lookupIp which ends up depending on the health of the local resolver. Specifically has this failing: Which leads to the test in: And we recently swapped out the node names from testnode to 127.0.0.1, so probably the culprit?
/ref
Interesting. I did swap out the node names in the unit test as part of to be 127.0.0.1, party because I thought that it wouldn't have any problems resolving during unit tests.
/cc

Discussion:
fakeMirrorClient *fakeMirrorClient } <del> const testKubeletHostname = "testnode" </del> <ins> const testKubeletHostname = "127.0.0.1" </ins> func newTestKubelet(t *testing.T) *TestKubelet { fakeDocker := &dockertools.FakeDockerClient{Errors: make(map[string]error), RemovedImages: util.StringSet{}}

kubelet.kubeClient = fakeKubeClient kubelet.os = kubecontainer.FakeOS{} <del> kubelet.hostname = "testnode" </del> <ins> kubelet.hostname = testKubeletHostname </ins> kubelet.runtimeUpThreshold = maxWaitForContainerRuntime kubelet.networkPlugin, _ = network.InitNetworkPlugin([]network.NetworkPlugin{}, "", network.NewFakeHost(nil)) if tempDir, err := ioutil.TempDir("/tmp", "kubelet_test."); err != nil {

testKubelet := newTestKubelet(t) kl := testKubelet.kubelet kl.nodeLister = testNodeLister{nodes: []api.Node{ <del> {ObjectMeta: api.ObjectMeta{Name: "testnode", Labels: map[string]string{"key": "B"}}}, </del> <ins> {ObjectMeta: api.ObjectMeta{Name: testKubeletHostname, Labels: map[string]string{"key": "B"}}}, </ins> }} testKubelet.fakeCadvisor.On("MachineInfo").Return(&cadvisorApi.MachineInfo{}, nil) testKubelet.fakeCadvisor.On("DockerImagesFsInfo").Return(cadvisorApiv2.FsInfo{}, nil)

kubelet := testKubelet.kubelet kubeClient := testKubelet.fakeKubeClient kubeClient.ReactFn = testclient.NewSimpleFake(&api.NodeList{Items: []api.Node{ <del> {ObjectMeta: api.ObjectMeta{Name: "127.0.0.1"}}, </del> <ins> {ObjectMeta: api.ObjectMeta{Name: testKubeletHostname}}, </ins> }}).ReactFn machineInfo := &cadvisorApi.MachineInfo{ MachineID:      "123",

kubeClient := testKubelet.fakeKubeClient kubeClient.ReactFn = testclient.NewSimpleFake(&api.NodeList{Items: []api.Node{ { <del> ObjectMeta: api.ObjectMeta{Name: "127.0.0.1"}, </del> <ins> ObjectMeta: api.ObjectMeta{Name: testKubeletHostname}, </ins> Spec:       api.NodeSpec{}, Status: api.NodeStatus{ Conditions: []api.NodeCondition{

} mockCadvisor.On("VersionInfo").Return(versionInfo, nil) expectedNode := &api.Node{ <del> ObjectMeta: api.ObjectMeta{Name: "127.0.0.1"}, </del> <ins> ObjectMeta: api.ObjectMeta{Name: testKubeletHostname}, </ins> Spec:       api.NodeSpec{}, Status: api.NodeStatus{ Conditions: []api.NodeCondition{

fakeDocker.VersionInfo = []string{} kubeClient.ReactFn = testclient.NewSimpleFake(&api.NodeList{Items: []api.Node{ <del> {ObjectMeta: api.ObjectMeta{Name: "127.0.0.1"}}, </del> <ins> {ObjectMeta: api.ObjectMeta{Name: testKubeletHostname}}, </ins> }}).ReactFn mockCadvisor := testKubelet.fakeCadvisor machineInfo := &cadvisorApi.MachineInfo{

mockCadvisor.On("VersionInfo").Return(versionInfo, nil) expectedNode := &api.Node{ <del> ObjectMeta: api.ObjectMeta{Name: "127.0.0.1"}, </del> <ins> ObjectMeta: api.ObjectMeta{Name: testKubeletHostname}, </ins> Spec:       api.NodeSpec{}, Status: api.NodeStatus{ Conditions: []api.NodeCondition{

func TestRegisterExistingNodeWithApiserver(t *testing.T) { testKubelet := newTestKubelet(t) kubelet := testKubelet.kubelet <del> kubelet.hostname = "127.0.0.1" </del> kubeClient := testKubelet.fakeKubeClient kubeClient.ReactFn = func(action testclient.FakeAction) (runtime.Object, error) { segments := strings.Split(action.Action, "-")

case "get": // Return an existing (matching) node on get. return &api.Node{ <del> ObjectMeta: api.ObjectMeta{Name: "127.0.0.1"}, Spec:       api.NodeSpec{ExternalID: "127.0.0.1"}, </del> <ins> ObjectMeta: api.ObjectMeta{Name: testKubeletHostname}, Spec:       api.NodeSpec{ExternalID: testKubeletHostname}, </ins> }, nil default: return nil, fmt.Errorf("no reaction implemented for %s", action.Action)