Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/4445

`-t` works on both old and new Docker versions, so it's best to use that.

Previously, it had to go through matrix-nginx-proxy.
It's exposed to Traefik directly via container labels now

Serving at a path other than `/` doesn't work well yet.

We were mounting our own configuration to
`/usr/share/nginx/html/config.json`, which is a symlink to
`/tmp/config.json`. So we effectively mount our file to
`/tmp/config.json`.

When starting:

- if Hydrogen sees a `CONFIG_OVERRIDE` environment variable,
  it will try to save it into our read-only config file and fail.

- if Hydrogen doesn't see a `CONFIG_OVERRIDE` environment variable (the
  path we go through, because we don't pass such a variable),
  it will try to copy its bundled configuration (`/config.json.bundled`)
  to `/tmp/config.json`. Because our configuration is mounted as read-only, it will
  fail.

In both cases, it will fail with:

> cp: can't create '/tmp/config.json': File exists

Source: 3720de36bb/docker/dynamic-config.sh

We work around this by mounting our configuration on top of the bundled
one (`/config.json.bundled`). We then let Hydrogen's startup script copy
it to `/tmp/config.json` (a tmpfs we've mounted into the container) and use it from there.

This paves the way for installing other roles into `roles/galaxy` using `ansible-galaxy`,
similar to how it's done in:

- https://github.com/spantaleev/gitea-docker-ansible-deploy
- https://github.com/spantaleev/nextcloud-docker-ansible-deploy

In the near future, we'll be removing a lot of the shared role code from here
and using upstream roles for it. Some of the core `matrix-*` roles have
already been extracted out into other reusable roles:

- https://github.com/devture/com.devture.ansible.role.postgres
- https://github.com/devture/com.devture.ansible.role.systemd_docker_base
- https://github.com/devture/com.devture.ansible.role.timesync
- https://github.com/devture/com.devture.ansible.role.vars_preserver
- https://github.com/devture/com.devture.ansible.role.playbook_runtime_messages
- https://github.com/devture/com.devture.ansible.role.playbook_help

We just need to migrate to those.

People often report and ask about these "failures".
More-so previously, when the `docker kill/rm` output was collected,
but it still happens now when people do `systemctl status
matrix-something` and notice that it says "FAILURE".

Suppressing to avoid further time being wasted on saying "this is
expected".

Reverts b1b4ba501fdfaa, 90c9801c560b6, a3c84f78ca9c65a, ..

I haven't really traced it (yet), but on some servers, I'm observing
`ansible-playbook ... --tags=start` completing very slowly, waiting
to stop services. I can't reproduce this on all Matrix servers I manage.
I suspect that either the systemd version is to blame or that some
specific service is not responding well to some `docker kill/rm` command.

`ExecStop` seems to work great in all cases and it's what we've been
using for a very long time, so I'm reverting to that.

ExecStopPost should allow us to clean up (docker kill + docker rm)
even if the ExecStart (docker run ..) command failed, and not just after
a graceful service stop was initiated.

Source: https://www.freedesktop.org/software/systemd/man/systemd.service.html#ExecStopPost=

It seems like it doesn't cause any issues for any of these services.

Also includes the dashboards for Synapse and for Node Exporter.

Again has only been tested on debian amd64 so far, but the grafana docker image is available for arm64 and arm32. Nice.

Initial attempt. Seems to work fine.

Only tested on debian amd64 so far