The Juju way would be to have a collection of charms which customize the vanilla image, rather than having a custom image to start with.
If you want to set all sorts of background things in your image, the best way is to have a subordinate charm which handles that. This way, you only need the vanilla, trusted, up to date standard image and all your personal changes are kept in one place.
To get access to the juju environment, please run the following from the place where you installed LDS:
# If you used the install-openstack tool, you want to do this first:
# Get an interactive shell with the right ENV sourced on the landscape
# server itself.
juju ssh landscape-server/0 sudo 'JUJU_HOME=/var/lib/landscape/juju-homes/`sudo ls -rt /var/lib/landscape/juju-homes/ | tail -1` sudo -u landscape -E bash'
# You should see a lot of openstack services with this command:
At this point, you can poke around, deploy services, and generally wreak havoc in your environment.
In other words, here is where you would deploy ceilometer.