LXC - DNS

Answering to your DNS LXC requests since 2014 =)

Download and configure

Requires node and npm. For ubuntu: sudo apt-get install nodejs npm

@> sudo npm install -g lxc-dns
@> lxc-dns

From git:

@> git clone https://github.com/eazel7/lxc-dns.git lxc-dns
@> (cd lxc-dns && npm install)

Run

sudo node lxc-dns/index.js

Test

This application is currently equivalent to listing the containers with lxc-ls --fancy and parsing the output to get a container IPv4 address.

My containers:

@> lxc-ls --fancy

NAME   STATE    IPV4        IPV6  AUTOSTART
-------------------------------------------
cont1  RUNNING  10.0.3.169  -     NO
cont2  RUNNING  10.0.3.98   -     NO
cont3  RUNNING  10.0.3.10   -     NO

So, if the DNS runs ok,

@> nslookup cont1 - 127.0.0.1

Server:		127.0.0.1
Address:	127.0.0.1#53

Non-authoritative answer:
Name:	cont1
Address: 10.0.3.169

Turning off a container should turn make it stop answering quite soon:

@> lxc-stop -n cont2
@> nslookup cont2 - 127.0.0.1
Server:		127.0.1.1
Address:	127.0.1.1#53

Non-authoritative answer:
*** Can't find cont2: No answer

DNS suffix

If you want to answer also to a certain DNS suffix, add an ACCEPT_SUFFIX environment variable.

@> sudo ACCEPT_SUFFIX=".lab1" node lxc-dns/index.js

Test with:

@> nslookup cont1.lab1 - 127.0.0.1

Server:		127.0.0.1
Address:	127.0.0.1#53

Non-authoritative answer:
Name:	cont1.lab1
Address: 10.0.3.169