configure for ipv6 dual stack

ansible/roles/k8s_control/defaults/main.yaml

@@ -1,10 +1,13 @@
 ---
 k8s_control_master_node: kube01.balsillie.net
 k8s_endpoint: k8s.balsillie.net
-k8s_address: "192.168.199.240"
+k8s_v4_address: "192.168.199.240"
+k8s_v6_address: "2a01:4f8:13b:f201::0240"
 k8s_api_port: "6443"
 k8s_cri_socket: /run/containerd/containerd.sock
 k8s_service_domain: cluster.internal
-k8s_pod_cidr: 10.128.0.0/16
-k8s_service_cidr: 10.96.0.0/16
+k8s_v4_pod_cidr: 10.128.0.0/16
+k8s_v6_pod_cidr: 2a01:4f8:13b:f202::00/64
+k8s_v4_service_cidr: 10.96.0.0/16
+k8s_v6_service_cidr: 2a01:4f8:13b:f203::00/64
 local_user: michael

ansible/roles/k8s_control/tasks/main.yaml

@@ -1,9 +1,12 @@
 ---
 - name: write cluster api address to hosts file
   ansible.builtin.lineinfile:
-    line: "{{ k8s_address }} {{ k8s_endpoint }}"
+    line: "{{ item }}"
     insertafter: EOF
     path: /etc/hosts
+  with_items:
+    - "{{ k8s_v4_address }} {{ k8s_endpoint }}"
+    - "{{ k8s_v6_address }} {{ k8s_endpoint }}"
 
 - name: create containerd config dir
   ansible.builtin.file:
@@ -42,6 +45,19 @@
     state: started
     enabled: true
 
+- name: ensure ip forwarding is active
+  ansible.posix.sysctl:
+    name: "{{ item.key }}"
+    value: "{{ item.value }}"
+    state: present
+    sysctl_set: true
+    reload: true
+  with_items:
+    - key: net.ipv6.conf.all.forwarding
+      value: '1'
+    - key: net.ipv4.conf.all.forwarding
+      value: '1'
+
 - name: kubeadm init master node
   when: ansible_host == hostvars[groups['k8s_control'][0]]['ansible_host']
   block:
@@ -50,15 +66,16 @@
     ansible.builtin.shell:
       cmd: |
         kubeadm init \
-        --control-plane-endpoint {{ k8s_address }} \
+        --control-plane-endpoint {{ k8s_endpoint }} \
         --cri-socket /run/containerd/containerd.sock \
-        --pod-network-cidr {{ k8s_pod_cidr }} \
-        --service-cidr {{ k8s_service_cidr }} \
+        --pod-network-cidr {{ k8s_v4_pod_cidr }},{{ k8s_v6_pod_cidr }} \
+        --service-cidr {{ k8s_v4_service_cidr }},{{ k8s_v6_service_cidr}} \
         --apiserver-bind-port {{ k8s_api_port }} \
         --apiserver-cert-extra-sans {{ k8s_endpoint }} \
-        --apiserver-cert-extra-sans {{ k8s_address }} \
+        --apiserver-cert-extra-sans {{ k8s_v4_ddress }} \
+        --apiserver-cert-extra-sans {{ k8s_v6_ddress }} \
         --node-name {{ ansible_hostname }} \
-        --feature-gates IPv6DualStack=false \
+        --feature-gates IPv6DualStack=true \
         --feature-gates PublicKeysECDSA=true \
         --service-dns-domain {{ k8s_service_domain }} \
       creates: /etc/kubernetes/admin.conf