Make sure that /usr/portage/local exists, then clone the overlay into it
mkdir -p /usr/portage/local
cd /usr/portage/local
git clone git://github.com/cloudkick/cloudkick-engineyard.git
Open up /etc/make.conf and add a line to the end:
PORTDIR_OVERLAY="${PORTDIR_OVERLAY}
/usr/portage/local/cloudkick-engineyard"
You should now be able to install the Cloudkick Agent by running
emerge -a cloudkick-agent
This will also pull in the cloudkick-config tool which helsp you configure the agent. When they are done installing run.
cloudkick-config
And provide your Cloudkick username and password when prompted. This will generate a basic /etc/cloudkick.conf. If this node already appears on your Cloudkick dashboard then this is all the configuration needed. Otherwise you will need to specify a node name in /etc/cloudkick.conf as described at https://support.cloudkick.com/Agent/Cloudkick.conf.
You probably also want to add the agent to the default runlevel:
rc-update add cloudkick-agent default
Now start the agent
/etc/init.d/cloudkick-agent start
And log into Cloudkick and make sure the agent is shown as connected in the Dashboard. If not, check /var/log/cloudkick-agent.log for troubleshooting information.
To update the Cloudkick Agent for Engine Yard, you will need to first pull in any updates to the overlay, then install any available updates.
cd /usr/portage/local/cloudkick-engineyard
git pull
emerge -a cloudkick-agent
Then, once the update is installed
/etc/init.d/cloudkick-agent restart
At this point you should be running the updated version of the agent.