docker: Enable IPv6 (with NAT)

roles/docker/files/daemon.json

@@ -1,5 +1,7 @@
 {
   "log-driver": "journald",
+  "ipv6": true,
+  "fixed-cidr-v6": "fd00:d0ce:d0ce:d0ce::/64",
   "dns": [
     "46.182.19.48",
     "74.82.42.42"

roles/docker/tasks/config.yml

@@ -1,4 +1,7 @@
 ---
+- name: Add IPv6 NAT iptables rules
+  shell: ip6tables -t nat -A POSTROUTING -s fd00:d0ce:d0ce:d0ce::/64 -j MASQUERADE && ip6tables-save > /etc/iptables/rules.v6
+
 - name: add docker configuration
   copy:
     dest: /etc/docker/daemon.json

roles/docker/tasks/packages.yml

@@ -19,3 +19,8 @@
     name: docker-ce
     update_cache: yes
     state: present
+
+- name: install iptables-persistent
+  apt:
+    name: iptables-persistent
+    state: present