Ability to override docker images

[George Kraft]

Originally brought up here: https://github.com/juju-solutions/layer-tigera-secure-ee/pull/5

In the Calico charm, it was possible to bring your own calicoctl resource and configure exact docker images for calico-node and calico-kube-controllers. It's not possible to do the same with the Tigera Secure EE charm.

The main use case, which is to specify a different docker registry, is still supported via the registry config.

One use case that is not supported is testing a new release of Tigera Secure EE without having to release a new charm.

[Joseph Borg (joeborg)]

Hey George, I think this is now done? https://github.com/charmed-kubernetes/layer-tigera-secure-ee/blob/master/metadata.yaml

[George Kraft (cynerva)]

Yeah, looks like it. Thanks.

Fixed with https://github.com/charmed-kubernetes/layer-tigera-secure-ee/pull/15

Release to stable with cs:~containers/tigera-secure-ee-55