[lxc-users] Resolve .lxc domain with Ubuntu 17.04

[Simos Xenitellis]

On Thu, Apr 13, 2017 at 10:49 PM, Norberto Bensa
<nbensa+lxcusers at gmail.com> wrote:
> Hello Simos,
>
> 2017-04-13 10:44 GMT-03:00 Simos Xenitellis <simos.lists at googlemail.com>:
>> I got stuck with this issue (Ubuntu Desktop with NetworkManager) and
>> wrote about it at
>> https://www.mail-archive.com/lxc-users@lists.linuxcontainers.org/msg07060.html
>
> For me, that doesn't work anymore with 17.04
>
> I tried a lot of configuration options with dnsmasq, network-manager,
> and systemd-resolved with Ubuntu and Kubuntu (real hardware and
> virtualized with kvm).
>

If you installed additional packages or changed configuration options,
you might have changed something that alters the default behaviour.

1. On Ubuntu Desktop, NetworkManager handles the networking configuration.
You should be able to do "ps aux | grep dnsmasq" and see at least one
"dnsmasq" process,
the one from NetworkManager.
For me, it is:
" 3653 ?        S      0:00 /usr/sbin/dnsmasq --no-resolv
--keep-in-foreground --no-hosts --bind-interfaces
--pid-file=/var/run/NetworkManager/dnsmasq.pid
--listen-address=127.0.1.1 --cache-size=0 --conf-file=/dev/null
--proxy-dnssec --enable-dbus=org.freedesktop.NetworkManager.dnsmasq
--conf-dir=/etc/NetworkManager/dnsmasq.d"

What is yours?

2. NetworkManager uses dnsmasq as a caching nameserver, and it does so
by configuring /etc/resolv.conf with:
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 127.0.1.1

Can you verify that you have exactly the same?

3. Then, LXD should have it's own "dnsmasq" process (as a DHCP server
and caching nameserver).
This dnsmasq process binds on a specific private IP address, which you
can find with, for example,

ifconfig lxdbr0

In my case, it is 10.0.125.1. I have an LXD container called
"mycontainer", therefore I can run

$ host mycontainer.lxd 10.0.125.1
Using domain server:
Name: 10.0.185.1
Address: 10.0.185.1#53
Aliases:

mycontainer.lxd has address 10.0.125.18
mycontainer.lxd has IPv6 address fd42:aacb:3658:4ca6:216:3e4f:fcd9:35e1
$ _

Do you get such a result? If not, perhaps you have the wrong IP address.
Also, if you ran "lxd init" several times, you might have lingering
"dnsmasq" process
that bind on port 53 on lxdbr0. Would need to reboot here.

If you can get up to this point, then the rest is really easy.

Simos