This is split out from matrix-cactus-comments (see 241779b583),
but also heavily inspired by `matrix-static-files`.

- 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.

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.

Signed-off-by: Sebastian Gumprich <github@gumpri.ch>

* Add construct for cactus comments role

* Adjust config files

* Add docker self build to defaults

* Adjust tasks

* Fix smaller syntax errors

* Fix env argument

* Add tmp path to allow container writing there

Background why I did this: https://docs.gunicorn.org/en/stable/settings.html#worker-tmp-dir

* Change port back to 5000 as not configurable in container

* Try to add appservice config file for synapse to use

* Inject appservice file

* Correct copied variable name

* Comment out unused app service file injection

would need mounting the appservice file to the synapse container i guess

* Move role before synapse to be able to inject during runtime

* Remove unused parts

* Change default user id to mirror official docs

* Add docs

* Update roles/matrix-cactus-comments/tasks/setup_install.yml

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

* Update roles/matrix-cactus-comments/templates/cactus_appservice.yaml.j2

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

* Generate secrets if necessary, adjust docs

* Rename cactusbot userid

* Shorten salt strings

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

* Use tmpfs instead of persistent mount

* Remove proxy option as it is nonsense

* Add download and serving of cc-client files

* Add documentation on client

* Clarify docs a bit

* Add nginx proxy to required services

Signed-off-by: Julian-Samuel Gebühr <julian-samuel@gebuehr.net>

* Use container address

Signed-off-by: Julian-Samuel Gebühr <julian-samuel@gebuehr.net>

* Correct comment of user id

Signed-off-by: Julian-Samuel Gebühr <julian-samuel@gebuehr.net>

* Use releases or local distributed client

Signed-off-by: Julian-Samuel Gebühr <julian-samuel@gebuehr.net>

* Move homeserver url to defaults

Signed-off-by: Julian-Samuel Gebühr <julian-samuel@gebuehr.net>

* Correct truth value

Signed-off-by: Julian-Samuel Gebühr <julian-samuel@gebuehr.net>

* Add documentation of variables

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

* Tabs vs. spaces

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

* Make nginx root configurable

Signed-off-by: Julian-Samuel Gebühr <julian-samuel@gebuehr.net>

* Complete ake nginx root configurable

Signed-off-by: Julian-Samuel Gebühr <julian-samuel@gebuehr.net>

* Fix file permission

Signed-off-by: Julian-Samuel Gebühr <julian-samuel@gebuehr.net>

* Fix lint errors

Signed-off-by: Julian-Samuel Gebühr <julian-samuel@gebuehr.net>

Signed-off-by: Julian-Samuel Gebühr <julian-samuel@gebuehr.net>
Co-authored-by: Slavi Pantaleev <slavi@devture.com>