Re: IPv6 setup on cloud image and cloud-init not working out

[Geert Stappers <stappers@stappers.nl>]

On Thu, Jul 01, 2021 at 12:31:02PM +0200, Dennis van Dok wrote:
> Hi,
> 
> I'm setting up and Openstack cluster and I was trying out a Debian 10 cloud image. The IPv4 address works via DHCP, and the metadata service provides the static data for IPv4 and IPv6. This gets written to /etc/network/interfaces.d/50-cloud-init, but the system won't honour the configuration because the lines in /etc/network/interfaces have a conflicting config.
> 
> /etc/network/interfaces contains
> 
> # The normal eth0
> allow-hotplug eth0
> iface eth0 inet dhcp
> 
> And the file 50-cloud-init has
> 
> ```
> # This file is generated from information provided by the datasource.  Changes
> # to it will not persist across an instance reboot.  To disable cloud-init's
> # network configuration capabilities, write a file
> # /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
> # network: {config: disabled}
> auto lo
> iface lo inet loopback
> 
> auto eth0
> iface eth0 inet static
>     address 145.110.26.4/28
>     post-up route add default gw 145.110.26.1 || true
>     pre-down route del default gw 145.110.26.1 || true
> 
> # control-alias eth0
> iface eth0 inet6 static
>     address 2a07:8500:140:1000::3/64
>     post-up route add -A inet6 default gw 2a07:8500:140:1000::1 || true
>     pre-down route del -A inet6 default gw 2a07:8500:140:1000::1 || true
> ```
> 
> There is probably more than one way to fix the issue, between how the cloud image is put together and the cloud-init software.
> 
> I suppose cloud-init could remove the dhcp line from /etc/network/interfaces.
> 

I suggest that cloud-init overwrites /etc/network/interfaces.


Groeten
Geert Stappers
-- 
Silence is hard to parse