Users admin API can now also modify user
type in addition to allowing it to be
set on user creation.

Signed-off-by: Jason Robinson <jasonr@matrix.org>
Co-authored-by: Brendan Abolivier <babolivier@matrix.org>

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>

* Mention callbacks introduced in v1.37.0

According to the documentation introduced in https://github.com/matrix-org/synapse/pull/10062

* Mention callbacks introduced in v1.39.0

According to https://github.com/matrix-org/synapse/pull/10386 and https://github.com/matrix-org/synapse/pull/9884

* Mention callbacks introduced in v1.42.0

According to https://github.com/matrix-org/synapse/pull/10524

* Mention callbacks introduced in v1.44.0 and v1.45.0

As per https://github.com/matrix-org/synapse/pull/10898, https://github.com/matrix-org/synapse/pull/10910 and https://github.com/matrix-org/synapse/pull/10894

* Mention callbacks introduced in v1.46.0

According to https://github.com/matrix-org/synapse/pull/10548

Document Synapse's behaviour when multiple modules register the same
callback/web resource/etc.

Co-authored-by: reivilibre <oliverw@matrix.org>

Co-authored-by: Brendan Abolivier <babolivier@matrix.org>

Co-authored-by: Azrenbeth <7782548+Azrenbeth@users.noreply.github.com>
Co-authored-by: Brendan Abolivier <babolivier@matrix.org>

Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

This is in the context of creating new module callbacks that modules in https://github.com/matrix-org/synapse-dinsic can use, in an effort to reconcile the spam checker API in synapse-dinsic with the one in mainline.

Note that a module callback already exists for 3pid invites (https://matrix-org.github.io/synapse/develop/modules/third_party_rules_callbacks.html#check_threepid_can_be_invited) but it doesn't check whether the sender of the invite is allowed to send it.

Co-authored-by: Erik Johnston <erik@matrix.org>

Based on matrix-doc switching from master -> main and
MSCs being merged.

Various updates to the install docs.

URL cache files are short-lived and it does not make sense to offload
them (eg. to the cloud) or back them up.

This is in the context of creating new module callbacks that modules in https://github.com/matrix-org/synapse-dinsic can use, in an effort to reconcile the spam checker API in synapse-dinsic with the one in mainline.

This adds a callback that's fairly similar to user_may_create_room except it also allows processing based on the invites sent at room creation.

- Use sytest:bionic. Sytest:latest is two years old (do we want
  CI to push out latest at all?) and comes with Python 3.5, which we
  explictly no longer support. The script now runs under PostgreSQL 10
  as a result.
- Advertise script in the docs
- Move pg testing script to scripts-dev directory
- Write to host as the script's exector, not root

A few changes to make it speedier to re-run the tests:

- Create blank DB in the container, not the script, so we don't have to
  `initdb` each time
- Use a named volume to persist the tox environment, so we don't have to
  fetch and install a bunch of packages from PyPI each time

Co-authored-by: reivilibre <olivier@librepush.net>

The major change is moving the decision of whether to use oEmbed
further up the call-stack. This reverts the _download_url method to
being a "dumb" functionwhich takes a single URL and downloads it
(as it was before #7920).

This also makes more minor refactorings:

* Renames internal variables for clarity.
* Factors out shared code between the HTML and rich oEmbed
  previews.
* Fixes tests to preview an oEmbed image.

It's a simplification, but one that'll help make the user directory logic easier
to follow with the other changes upcoming. It's not strictly required for those
changes, but this will help simplify the resulting logic that listens for
`m.room.member` events and generally make the logic easier to follow.

This means the config option `search_all_users` ends up controlling the
search query only, and not the data we store. The cost of doing so is an
extra row in the `user_directory` and `user_directory_search` tables for
each local user which

- belongs to no public rooms
- belongs to no private rooms of size ≥ 2

I think the cost of this will be marginal (since they'll already have entries
 in `users` and `profiles` anyway).

As a small upside, a homeserver whose directory was built with this
change can toggle `search_all_users` without having to rebuild their
directory.

Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

No functional changes here. This came out as I was working to tackle #5677 

* Split up the documentation in several files rather than one huge one
* Add examples for each callback category
* Other niceties like fixing https://github.com/matrix-org/synapse/issues/10632
* Add titles to callbacks so they're easier to find in the navigation panels and link to

Also refactors some of the registration of endpoints on workers.

This adds configuration options (under an `oembed` section) to
configure which URLs are matched to use oEmbed for URL
previews.