This is provoked by Github issue #46.
No client had made use of the well-known mechanism
so far, so the set up performed by this playbook was not tested
and turned out to be a little deficient.
Even though /.well-known/matrix/client is usually requested with a
simple request (no preflight), it's still considered cross-origin
and [CORS](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS)
applies. Thus, the file always needs to be served with the appropriate
`Access-Control-Allow-Origin` header.
Github issue #46 attempts to fix it at the "reverse-proxying" layer,
which may work, but would need to be done for every server.
It's better if it's done "upstream", so that all reverse-proxy
configurations can benefit.
Trying to:
- stay closer to naming in Synapse (autojoin -> auto_join)
- not create new variable namespaces (`matrix_homeserver_`),
when existing ones (`matrix_synapse_`) are more suitable
- allow `null` (`~`) values for `matrix_riot_web_welcome_user_id`
- render things like `auto_join_rooms` in `homeserver.yaml` more prettily
- fix breakage in `config.json` where `matrix_riot_web_roomdir_servers`
was rendered as YAML and not as JSON
- simplify code (especially in riot-web's `config.json`), which used
`if` statements that could have been omitted
- avoid changing comments in `homeserver.yaml` which are not ours,
so that we can keep closer to the configuration file generated by upstream
Pretty much all variables live in their own `matrix_<whatever>`
prefix now and are grouped closer together in the default
variables file (`roles/matrix-server/defaults/main.yml`).
It should be `/bin/mkdir` and `/bin/chown` on Ubuntu 18.04 for example.
Still, it doesn't seem like we need to create and chown these
directories at all, since the playbook takes care of creating them
and setting appropriate permission by itself.
`--log-driver=none` is used for all Docker containers now.
All these containers are started through systemd anyway and get logged in journald,
so there's no need for Docker to be logging the same thing using the default `json-file` driver.
Doing that was growing `/var/lib/docker/containers/..` infinitely until service/container restart.
As a result of this, things like `docker logs matrix-synapse` won't work anymore.
`journalctl -u matrix-synapse` is how one can see the logs.
