Small LXC Writeup

stacksofplates

So I've been using LXC for some things. I figured I'd do a quick small write up. I'm using it on Ubuntu because each distro is different on how they deploy it and it's most documented with Ubuntu and seems to have the least issues.

Start by installing lxc

sudo apt-get install lxc lxc-templates

There are a couple ways to do networking. I'm running these on my desktop so I can bridge the NIC and have addresses for each container on my subnet. If you're running on a VPS or cloud server you will most likely need to use iptables to port forward to the container.

For now I'll just show how to use the containers themselves.

To list containers you can use

sudo lxc-ls --fancy

It will give you this output

NAME    STATE    IPV4        IPV6  AUTOSTART  
--------------------------------------------  
d1      RUNNING  10.0.0.30   -     NO
xo      RUNNING  10.0.0.188  -     NO

Next create a new container. I'll use Ubuntu trusty 64 bit.

sudo lxc-create -t download -n cont1 -- -d ubuntu -r trusty -a amd64

That will download the ubuntu trusty 64 bit template, name the container cont1, and create the file system. It takes a little longer the first time since it needs to download everything.

Once it's finished just type:

sudo lxc-start -n cont1 -d

If you don't run it as a daemon, you will be launched into the container and then have to shut it down to get out. This way it runs in the background.

Next you will need to attach to the container and change the default user's (ubuntu) password.

sudo lxc-attach -n cont1

passwd ubuntu

exit

To attach to the container with a console just type:

sudo lxc-console -n cont1

And to leave the console use ctrl+a q

If you want to start up a handful at once here's a quick one liner:

for i in {1..5}; do  (sudo lxc-create -t download -n cont$i -- -d ubuntu -r trusty -a amd64 && echo "Container cont$i is finished..."); done

You can run unprivileged containers where normal non-sudo users can create the container and it's limited to their space, but it's some more work.