cloud-init-centos-7-ipv6.yml

#cloud-config
# vim: syntax=yaml
# cloud-init-centos-7-ipv6.yml
#
# This one is intended for older instances where:
# * the ENA adapter is in use, for example for the t3 and m5 instance types.
# * you want both IPv4 and IPv6 networking enabled
# * you have disabled network interface stable renaming so that eth0 will be
#   the first interface as follows:
#   
#   Edit /etc/sysconfig/grub and replace the GRUB_CMDLINE_LINUX line as follows:
#   
#     GRUB_CMDLINE_LINUX="console=tty0 crashkernel=auto console=ttyS0,115200 net.ifnames=0"
#
#   Run this command:
#
#      grub2-mkconfig -o /boot/grub2/grub.cfg
#
# * you have rebuilt the initramfs with support for the ena drivers, by
#   installing the install the "dracut-config-generic" package, with:
#
#      yum install dracut-config-generic -q -y
#
# * you have run this command to rebuild the kernel initramfs in /boot:
#
#      dracut -f
#
# Partially derived from:
# * ldennison's comment in https://bugs.centos.org/view.php?id=14760 
# * hhsnow's comment in https://bugs.centos.org/view.php?id=14107
# * the cloud-init config in https://docs.aws.amazon.com/vpc/latest/userguide/vpc-migrate-ipv6.html#vpc-migrate-ipv6-instance-types
#
# The key change here is that we added /etc/sysconfig/network to the files sed considers,
#
# Tested on CentOS Linux release 7.6.1810 (Core) and a t3.micro
# instance on 2019-05-19
#
# Author:
#    Richard Bullington-Mcguire <rbulling@obscure.org> / @obscurerichard 
#
# Copyright (C) 2019 by The Obscure Organization
# MIT licensed. See the LICENSE file for details.
network:
  version: 1
  config:
  - type: physical
    name: eth0
    subnets:
      - type: dhcp4
      - type: dhcp6

bootcmd:
  - "sed -i 's/^IPV6_AUTOCONF=.*$/IPV6_AUTOCONF=yes/g' /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network"
  - systemctl restart network