- Any event that relates to the setup of the unit or application invoke the configure_charm method
- Unit setup should be in configure_unit
- Application setup should be in configure_application
- Do not defer events (unless you really have to)
- When writing a relation handle keep in mind the the handler may be used by other charms to avoid calling back to specific charm methods in the body of the handler. Instead have the charm pass eveything when the handler is initialaised. This is not always possible.
- SSHing into a container
A unit consists of a pod made up of a charm container and one or more payload containers. The charm container can be accessed the normal way with:
juju ssh keystone/0
The payload container(s) can all be accessed by adding the --container flag. e.g.
juju ssh -m openstack --container neutron-server neutron/0
If you don't know the payload container names the just add garbage for the name and juju will list them:
juju ssh -m openstack --container garbage neutron/0 ERROR container "garbage" must be one of charm, neutron-server
- If a unit is stuck coming up then you can use the
kubectlcommand line to get more information:
The pod name is the unit name with the / replaced with a - so the pod for keystone/0 is keystone-0. The pods are in a namespace which corresponds to the model name. eg
kubectl describe pod -n openstack keystone-0
- Install into the container
The charm and payload container do not have an editor in them by default but you can use apt to install one (or anything else).
- Get adminrc details
The keystone charm has an action to retrieve admin credentials
juju run -m openstack keystone/0 get-admin-account