[lxc-users] How to check DNS records of containers

[Fajar A. Nugraha]

On Wed, Jun 28, 2017 at 6:34 PM, Adil Baig <simplyadilb at gmail.com> wrote:

> This hasn't worked for me.
>
> lxc network show lxdbr0
> description: ""
> config:
>   dns.domain: lxd
>   dns.mode: managed
>   ipv4.address: 10.0.1.1/24
>   ipv4.dhcp.ranges: 10.0.1.2-10.0.1.254
>   ipv4.nat: "true"
>   ipv6.address: none
>   raw.dnsmasq: conf-file=/home/ubuntu/stockopedia-lxd-dnsmasq.conf
>

why is raw.dsnmasq here?
while it might not be the cause of your non-working system, best to start
with known-good configuration first.

I did steps 1.2 and 5. The rest were already in place (lxc version 2.14). I
> killed dnsmasq
>

Again, the one doing resolving on the host. Not the one started by lxd to
manage lxdbr0.

To be more accurate:
- lxd's dnsmasq should already provide DNS resolving for containers (e.g.
"ping devop-tools.lxd" should work from inside any of your containers, as
long as devop-tools is using DHCP).
- using dnsmasq as DNS resolver on the host as well would simplify the
configuration. However it should work with any DNS server (e.g. bind) as
long as you tell it to "forward all queries for .lxd domain to lxd's
dnsmasq".



> and restarted lxd service (sudo service lxd restart) .
>
>
That should not be necessary

 ping devop-tools.lxd
> ping: unknown host devop-tools.lxd
>
>
Does it work from another container? If not, you need to fix that first.

Does "dig" work when you tell it to use lxdbr0's IP as nameserver? e.g.
"dig devop-tools.lxd @10.0.1.1"

Do you get these entries when restarting the host's dnsmasq? If not, you
probably edit the wrong file in step (5)
# systemctl restart dnsmasq
# systemctl status dnsmasq
...
Jun 28 20:43:29 ip-172-31-0-128 dnsmasq[92746]: using nameserver
10.0.3.1#53 for domain lxd

Does your host's /etc/resolv.conf now points to localhost? It should, since
dnsmasq would make it so. If not, you need to fix that.

-- 
Fajar
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