diff --git a/cmd/kubeadm/app/apis/kubeadm/BUILD b/cmd/kubeadm/app/apis/kubeadm/BUILD index 869f57a992b..8d9a0a3aabb 100644 --- a/cmd/kubeadm/app/apis/kubeadm/BUILD +++ b/cmd/kubeadm/app/apis/kubeadm/BUILD @@ -11,6 +11,7 @@ go_library( "doc.go", "register.go", "types.go", + "well_known_labels.go", "zz_generated.deepcopy.go", ], deps = [ diff --git a/cmd/kubeadm/app/apis/kubeadm/well_known_labels.go b/cmd/kubeadm/app/apis/kubeadm/well_known_labels.go new file mode 100644 index 00000000000..f2fb530fdc0 --- /dev/null +++ b/cmd/kubeadm/app/apis/kubeadm/well_known_labels.go @@ -0,0 +1,43 @@ +/* +Copyright 2017 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 kubeadm + +// Role labels are applied to Nodes to mark their purpose. In particular, we +// usually want to distinguish the master, so that we can isolate privileged +// pods and operations. +// +// Originally we relied on not registering the master, on the fact that the +// master was Unschedulable, and on static manifests for master components. +// But we now do register masters in many environments, are generally moving +// away from static manifests (for better manageability), and working towards +// deprecating the unschedulable field (replacing it with taints & tolerations +// instead). +// +// Even with tainting, a label remains the easiest way of making a positive +// selection, so that pods can schedule only to master nodes for example, and +// thus installations will likely define a label for their master nodes. +// +// So that we can recognize master nodes in consequent places though (such as +// kubectl get nodes), we encourage installations to use the well-known labels. +// We define NodeLabelRole, which is the preferred form, but we will also recognize +// other forms that are known to be in widespread use (NodeLabelKubeadmAlphaRole). + +const ( + // NodeLabelKubeadmAlphaRole is a label that kubeadm applies to a Node as a hint that it has a particular purpose. + // Use of NodeLabelRole is preferred. + NodeLabelKubeadmAlphaRole = "kubeadm.alpha.kubernetes.io/role" +) diff --git a/pkg/printers/internalversion/BUILD b/pkg/printers/internalversion/BUILD index fa0ad5d66b0..6d5281bd171 100644 --- a/pkg/printers/internalversion/BUILD +++ b/pkg/printers/internalversion/BUILD @@ -55,6 +55,7 @@ go_library( "printers.go", ], deps = [ + "//cmd/kubeadm/app/apis/kubeadm:go_default_library", "//federation/apis/federation:go_default_library", "//federation/apis/federation/v1beta1:go_default_library", "//federation/client/clientset_generated/federation_clientset:go_default_library", diff --git a/pkg/printers/internalversion/describe.go b/pkg/printers/internalversion/describe.go index 6f0299612af..d8ef33de39f 100644 --- a/pkg/printers/internalversion/describe.go +++ b/pkg/printers/internalversion/describe.go @@ -2436,6 +2436,7 @@ func describeNode(node *api.Node, nodeNonTerminatedPodsList *api.PodList, events return tabbedString(func(out io.Writer) error { w := NewPrefixWriter(out) w.Write(LEVEL_0, "Name:\t%s\n", node.Name) + w.Write(LEVEL_0, "Role:\t%s\n", findNodeRole(node)) printLabelsMultiline(w, "Labels", node.Labels) printAnnotationsMultiline(w, "Annotations", node.Annotations) printNodeTaintsMultiline(w, "Taints", node.Spec.Taints) diff --git a/pkg/printers/internalversion/printers.go b/pkg/printers/internalversion/printers.go index 85d8a70a509..b0386581388 100644 --- a/pkg/printers/internalversion/printers.go +++ b/pkg/printers/internalversion/printers.go @@ -41,6 +41,7 @@ import ( "k8s.io/apimachinery/pkg/labels" "k8s.io/apimachinery/pkg/runtime" "k8s.io/apimachinery/pkg/util/sets" + "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm" "k8s.io/kubernetes/federation/apis/federation" "k8s.io/kubernetes/pkg/api" "k8s.io/kubernetes/pkg/api/events" @@ -1156,6 +1157,10 @@ func printNode(obj *api.Node, options printers.PrintOptions) ([]metav1alpha1.Tab if obj.Spec.Unschedulable { status = append(status, "SchedulingDisabled") } + role := findNodeRole(obj) + if role != "" { + status = append(status, role) + } row.Cells = append(row.Cells, obj.Name, strings.Join(status, ","), translateTimestamp(obj.CreationTimestamp), obj.Status.NodeInfo.KubeletVersion) if options.Wide { @@ -1186,6 +1191,19 @@ func getNodeExternalIP(node *api.Node) string { return "" } +// findNodeRole returns the role of a given node, or "" if none found. +// The role is determined by looking in order for: +// * a kubernetes.io/role label +// * a kubeadm.alpha.kubernetes.io/role label +// If no role is found, ("", nil) is returned +func findNodeRole(node *api.Node) string { + if role := node.Labels[kubeadm.NodeLabelKubeadmAlphaRole]; role != "" { + return role + } + // No role found + return "" +} + func printNodeList(list *api.NodeList, options printers.PrintOptions) ([]metav1alpha1.TableRow, error) { rows := make([]metav1alpha1.TableRow, 0, len(list.Items)) for i := range list.Items { diff --git a/pkg/printers/internalversion/printers_test.go b/pkg/printers/internalversion/printers_test.go index 74e603a9ae7..701e9678f2a 100644 --- a/pkg/printers/internalversion/printers_test.go +++ b/pkg/printers/internalversion/printers_test.go @@ -825,6 +825,16 @@ func TestPrintNodeStatus(t *testing.T) { }, status: "Unknown,SchedulingDisabled", }, + { + node: api.Node{ + ObjectMeta: metav1.ObjectMeta{ + Name: "foo12", + Labels: map[string]string{"kubeadm.alpha.kubernetes.io/role": "node"}, + }, + Status: api.NodeStatus{Conditions: []api.NodeCondition{{Type: api.NodeReady, Status: api.ConditionTrue}}}, + }, + status: "Ready,node", + }, } for _, test := range table {