This gets us started on adding a Traefik role and hooking Traefik:
- directly to services which support Traefik - we only have a few of
these right now, but the list will grow
- to matrix-nginx-proxy for most services that integrate with
matrix-nginx-proxy right now
Traefik usage should be disabled by default for now and nothing should
change for people just yet.
Enabling these experiments requires additional configuration like this:
```yaml
devture_traefik_ssl_email_address: '.....'
matrix_playbook_traefik_role_enabled: true
matrix_playbook_traefik_labels_enabled: true
matrix_ssl_retrieval_method: none
matrix_nginx_proxy_https_enabled: false
matrix_nginx_proxy_container_http_host_bind_port: ''
matrix_nginx_proxy_container_federation_host_bind_port: ''
matrix_nginx_proxy_trust_forwarded_proto: true
matrix_nginx_proxy_x_forwarded_for: '$proxy_add_x_forwarded_for'
matrix_coturn_enabled: false
```
What currently works is:
reverse-proxying for all nginx-proxy based services **except** for the Matrix homeserver
(both Client-Server an Federation traffic for the homeserver don't work yet)
- forego removing Docker images - it's not effective anyway, because it
only removes the last version.. which is a drop in the bucket, usually
- do not reload systemd - it's none of our business. `--tags=start`,
etc., handle this
- combine all uninstall tasks under a single block, which only runs if
we detect traces (a leftover systemd .service file) of the component.
If no such .service is detected, we skip them all. This may lead to
incorect cleanup in rare cases, but is good enough for the most part.
