chore: only label nodes with kubernetes.io/role if they need it (#4827)

Azure · Feb 11, 2022 · fe9e4d4 · fe9e4d4
1 parent db2a3b4
commit fe9e4d4
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Showing 3 changed files with 19 additions and 16 deletions.
diff --git a/parts/k8s/cloud-init/artifacts/label-nodes.sh b/parts/k8s/cloud-init/artifacts/label-nodes.sh
@@ -1,20 +1,21 @@
 #!/usr/bin/env bash
 
-# Applies missing master and agent labels to Kubernetes nodes.
+# This script looks for nodes that don't have the required kubernetes.io/role label,
+# and then labels them appropriately
 #
-# Kubelet 1.16+ rejects the `kubernetes.io/role` and `node-role.kubernetes.io`
-# labels in its `--node-labels` argument, but they need to be present for
-# backward compatibility.
+# Because nodes can't self-label their role in this way,
+# we need control plane nodes to do this continually
+# to ensure that new nodes get the role labels quickly
 
 set -euo pipefail
 
 KUBECONFIG="$(find /home/*/.kube/config)"
 KUBECTL="kubectl --kubeconfig=${KUBECONFIG}"
 
-MASTER_SELECTOR="kubernetes.azure.com/role!=agent,kubernetes.io/role!=agent"
-MASTER_LABELS="kubernetes.azure.com/role=master kubernetes.io/role=master node-role.kubernetes.io/master="
-AGENT_SELECTOR="kubernetes.azure.com/role!=master,kubernetes.io/role!=master"
-AGENT_LABELS="kubernetes.azure.com/role=agent kubernetes.io/role=agent node-role.kubernetes.io/agent="
+MASTER_SELECTOR="kubernetes.azure.com/role=master,kubernetes.io/role!=master,node-role.kubernetes.io/master!="
+MASTER_LABELS="kubernetes.io/role=master node-role.kubernetes.io/master="
+AGENT_SELECTOR="kubernetes.azure.com/role=agent,kubernetes.io/role!=agent,node-role.kubernetes.io/agent!="
+AGENT_LABELS="kubernetes.io/role=agent node-role.kubernetes.io/agent="
 
 ${KUBECTL} label nodes --overwrite -l $MASTER_SELECTOR $MASTER_LABELS
 ${KUBECTL} label nodes --overwrite -l $AGENT_SELECTOR $AGENT_LABELS

diff --git a/pkg/engine/templates_generated.go b/pkg/engine/templates_generated.go
diff --git a/test/e2e/kubernetes/kubernetes_test.go b/test/e2e/kubernetes/kubernetes_test.go
@@ -2802,6 +2802,7 @@ var _ = Describe("Azure Container Cluster using the Kubernetes Orchestrator", fu
 				}
 				labels := n.Metadata.Labels
 				Expect(labels).To(HaveKeyWithValue("kubernetes.io/role", role))
+				Expect(labels).To(HaveKeyWithValue(fmt.Sprintf("node-role.kubernetes.io/%s", role), ""))
 				Expect(labels).To(HaveKey(fmt.Sprintf("node-role.kubernetes.io/%s", role)))
 				if role == "master" && common.IsKubernetesVersionGe(
 					eng.ExpandedDefinition.Properties.OrchestratorProfile.OrchestratorVersion, "1.17.1") {