Add pre-kubeadm join commands to worker nodes

- Also pre-create a DNS Name for the frontend LB's IP that get assigned to the controlplane VM.

Author: nawazkh

templates/cluster-template-azure-bastion.yaml

@@ -29,6 +29,12 @@ spec:
     name: ${CLUSTER_IDENTITY_NAME}
   location: ${AZURE_LOCATION}
   networkSpec:
+    apiServerLB:
+      frontendIPs:
+      - name: ${CLUSTER_NAME}-api-lb
+        publicIP:
+          dnsName: ${CLUSTER_NAME}.${AZURE_LOCATION}.cloudapp.azure.com
+          name: ${CLUSTER_NAME}-api-lb
     subnets:
     - name: control-plane-subnet
       role: control-plane
@@ -189,7 +195,9 @@ spec:
           kubeletExtraArgs:
             cloud-provider: external
           name: '{{ ds.meta_data["local_hostname"] }}'
-      preKubeadmCommands: []
+      preKubeadmCommands:
+      - echo '10.0.0.4   ${CLUSTER_NAME}.${AZURE_LOCATION}.cloudapp.azure.com' >>
+        /etc/hosts
 ---
 apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
 kind: AzureClusterIdentity

templates/cluster-template-azure-cni-v1.yaml

@@ -5,8 +5,11 @@ resources:
 - ../base
 - machine-deployment.yaml
 - ../../azure-cluster-identity
+
 patches:
 - path: ../../azure-cluster-identity/azurecluster-identity-ref.yaml
+- path: patches/control-plane.yaml
+- path: patches/kubeadm-config-template.yaml
 
 sortOptions:
   order: fifo

templates/cluster-template-edgezone.yaml

@@ -0,0 +1,15 @@
+apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
+kind: AzureCluster
+metadata:
+  name: ${CLUSTER_NAME}
+spec:
+  networkSpec:
+    apiServerLB:
+      # Hack: We pre-create this public IP and the DNS name to use it in the
+      # worker node's /etc/hosts. This resolves the routing issue due to newly
+      # implemented security rules in Azure.
+      frontendIPs:
+        - name: ${CLUSTER_NAME}-api-lb
+          publicIP:
+            name: ${CLUSTER_NAME}-api-lb
+            dnsName: ${CLUSTER_NAME}.${AZURE_LOCATION}.cloudapp.azure.com

templates/cluster-template-ephemeral.yaml

@@ -0,0 +1,14 @@
+apiVersion: bootstrap.cluster.x-k8s.io/v1beta1
+kind: KubeadmConfigTemplate
+metadata:
+  name: "${CLUSTER_NAME}-md-0"
+spec:
+  template:
+    spec:
+      # Hack: /etc/hosts file is updated with a pre-created DNS name of the API server
+      # so that worker nodes can access the API server using the internal IP.
+      # 10.0.0.4 is the default IP that gets assigned to a single control plane
+      # cluster scenario.
+      # TODO: Replace 10.0.0.4 with an internal LB that has backend pools pointed to the control plane nodes.
+      preKubeadmCommands:
+        - echo '10.0.0.4   ${CLUSTER_NAME}.${AZURE_LOCATION}.cloudapp.azure.com' >> /etc/hosts

templates/cluster-template-windows.yaml

@@ -7,6 +7,7 @@ resources:
 
 patches:
 - path: ../base-windows-containerd/cluster.yaml
+- path: patches/kubeadm-config-template.yaml
 
 sortOptions:
   order: fifo