[lxc-users] Converting network from LXC to LXD

[Fajar A. Nugraha]

On Sun, Dec 22, 2019 at 1:09 AM John Lane <lxc at jelmail.com> wrote:
>
> On 21/12/2019 16:51, John Lane wrote:
>
> >
> > I can't do this:
> >
> > $ lxc config device set mycontainer eth0 ipv4.address 192.168.21.2/24
> >                                                Error: Invalid devices:
> > Invalid value for device option ipv4.address: Not an IPv4 address:
> > 192.168.21.2/24
> >
> > Also there appears to be no setting for gateway:
> >
> > $ lxc config device set mycontainer eth0 ipv4.gateway 192.168.21.1
> > Error: Invalid devices: Invalid device option: ipv4.gateway
> >
>
> Reading this
> (https://github.com/lxc/lxd/issues/1259#issuecomment-166416979):

On that same page:
https://github.com/lxc/lxd/issues/1259#ref-pullrequest-136128816

> I guess that it doesn't work.

If you use lxd-managed bridge (e.g. lxdbr0), you can configure it's
built-in dhcp server (dnsmasq) to allways allocate fixed ip using
something like this (in this example lxdbr0 is 10.0.3.1/24)

devices:
  eth0:
    host_name: c1-0
    ipv4.address: 10.0.3.221
    name: eth0
    nictype: bridged
    parent: lxdbr0
    type: nic


If it's not on lxd-managed bridged (e.g. physical interface), you can
simply configure it inside the container (which you did already), or
do something like this on container config:

config:
  raw.lxc: |-
    lxc.net.0.ipv4.address=10.0.4.2/24
    lxc.net.0.ipv4.gateway=10.0.4.1

... and tell the container OS to leave it alone
# cat /etc/network/interfaces
auto eth0
iface eth0 inet manual


>
> I also tried using "lxc.raw" to work around it but could not get that to
> work. I kept getting "Config parsing error: Initialize LXC: Failed to
> load raw.lxc". Does raw.lxc not work any more?

It works, but you used deprecated lxc config lines, which didn't work
starting lxc 3.0

> I don't know if there is a page accessible on the main LXD site
> documentation that explains this kind of thing which would be useful to
> help transitioning from plain-old lxc.

https://github.com/lxc/lxd/issues/4393#issuecomment-378181793
https://linuxcontainers.org/lxc/manpages//man5/lxc.container.conf.5.html
https://discuss.linuxcontainers.org/t/lxc-3-0-0-has-been-released/1449
https://discuss.linuxcontainers.org/t/lxc-2-1-has-been-released/487

-- 
Fajar