mattermost TLS with new psql charm

[Maksim Beliaev]

Current Mattermost charm will crash (container crash) if related to new postgres charm (from edge)

That is because new psql does not have TLS built-in. Fix is simple, integrate psql with certificates charm.
However, MM should not have container crash but go to the blocked state with clear error message to a user until TLS is available

following will work:
juju deploy postgresql-k8s --channel edge
juju deploy mattermost-k8s
juju deploy tls-certificates-operator --channel=edge
juju config tls-certificates-operator generate-self-signed-certificates="true" ca-common-name="Test CA"
# Enable TLS via relation.
juju relate postgresql-k8s tls-certificates-operator
juju status --relations
juju status --watch 2s
juju integrate mattermost-k8s:db postgresql-k8s:db
juju status --watch 2s

curl 10.1.72.140:8065/api/v4/system/ping

Error from MM:
$ microk8s kubectl logs -n mm-test mattermost-k8s-75bd6c44bd-bbrnw
Defaulted container "mattermost-k8s" out of: mattermost-k8s, juju-pod-init (init)
Error: failed to load configuration: failed to initialize: driver: postgres, message: failed to grab connection to the database, command: grabbing_connection, originalError: pq: SSL is not enabled on the server, query

[Tom Haddon (mthaddon)]

I've updated the deployment instructions (https://charmhub.io/mattermost-k8s) for Mattermost to clarify this, but I agree we should fix the charm to more gracefully handle this.