A year ago I wrote http://jrwren.wrenfam.com/blog/2015/05/26/ubuntu-cloud-image-based-containers-with-lxc/
Since then, LXD became the best way to use LXC.
By default, LXD already uses ubuntu-cloudimg images.
The lesser know feature is using cloud-config with LXD. It turns out it is very easy to pass user-data to an LXD instance when you start it, just like you would on any cloud provider.
LXD even has the -e option to make your LXD instance ephemeral. It will be deleted automatically when you stop it.
Just like in that previous blog post, I create a file named one.yaml. The name can be anything. Then i start it:
lxc launch ubuntu:14.04 crisp-Hadley -c user.user-data="$(cat one.yaml)"
That is all there is to it.
Here is an example of config similar to what I used recently to QA a build configuration:
#cloud-config
output:
all: "|tee -a /tmp/cloud.out"
#hostname: {{ hostname }}
bootcmd:
- rm -f /etc/dpkg/dpkg.cfg.d/multiarch
apt_sources:
- source: ppa:yellow/ppa
ssh_import_id: [evarlast] # use -S option
packages:
- make
final_message: "The system is finally up, after $UPTIME seconds"
runcmd:
- cd /home/ubuntu
- git clone https://www.github.com/jrwren/myproject
- cd myproject
- make deps run