Merge tag 'v1.51.0'

Synapse 1.51.0 (2022-01-25)
===========================

No significant changes since 1.51.0rc2.

Synapse 1.51.0 deprecates `webclient` listeners and non-HTTP(S) `web_client_location`s. Support for these will be removed in Synapse 1.53.0, at which point Synapse will not be capable of directly serving a web client for Matrix.

Synapse 1.51.0rc2 (2022-01-24)
==============================

Bugfixes
--------

- Fix a bug introduced in Synapse 1.40.0 that caused Synapse to fail to process incoming federation traffic after handling a large amount of events in a v1 room. ([\#11806](https://github.com/matrix-org/synapse/issues/11806))

Synapse 1.51.0rc1 (2022-01-21)
==============================

Features
--------

- Add `track_puppeted_user_ips` config flag to record client IP addresses against puppeted users, and include the puppeted users in monthly active user counts. ([\#11561](https://github.com/matrix-org/synapse/issues/11561), [\#11749](https://github.com/matrix-org/synapse/issues/11749), [\#11757](https://github.com/matrix-org/synapse/issues/11757))
- Include whether the requesting user has participated in a thread when generating a summary for [MSC3440](https://github.com/matrix-org/matrix-doc/pull/3440). ([\#11577](https://github.com/matrix-org/synapse/issues/11577))
- Return an `M_FORBIDDEN` error code instead of `M_UNKNOWN` when a spam checker module prevents a user from creating a room. ([\#11672](https://github.com/matrix-org/synapse/issues/11672))
- Add a flag to the `synapse_review_recent_signups` script to ignore and filter appservice users. ([\#11675](https://github.com/matrix-org/synapse/issues/11675), [\#11770](https://github.com/matrix-org/synapse/issues/11770))

Bugfixes
--------

- Fix a long-standing issue which could cause Synapse to incorrectly accept data in the unsigned field of events
  received over federation. ([\#11530](https://github.com/matrix-org/synapse/issues/11530))
- Fix a long-standing bug where Synapse wouldn't cache a response indicating that a remote user has no devices. ([\#11587](https://github.com/matrix-org/synapse/issues/11587))
- Fix an error that occurs whilst trying to get the federation status of a destination server that was working normally. This admin API was newly introduced in Synapse v1.49.0. ([\#11593](https://github.com/matrix-org/synapse/issues/11593))
- Fix bundled aggregations not being included in the `/sync` response, per [MSC2675](https://github.com/matrix-org/matrix-doc/pull/2675). ([\#11612](https://github.com/matrix-org/synapse/issues/11612), [\#11659](https://github.com/matrix-org/synapse/issues/11659), [\#11791](https://github.com/matrix-org/synapse/issues/11791))
- Fix the `/_matrix/client/v1/room/{roomId}/hierarchy` endpoint returning incorrect fields which have been present since Synapse 1.49.0. ([\#11667](https://github.com/matrix-org/synapse/issues/11667))
- Fix preview of some GIF URLs (like tenor.com). Contributed by Philippe Daouadi. ([\#11669](https://github.com/matrix-org/synapse/issues/11669))
- Fix a bug where only the first 50 rooms from a space were returned from the `/hierarchy` API. This has existed since the introduction of the API in Synapse v1.41.0. ([\#11695](https://github.com/matrix-org/synapse/issues/11695))
- Fix a bug introduced in Synapse v1.18.0 where password reset and address validation emails would not be sent if their subject was configured to use the 'app' template variable. Contributed by @br4nnigan. ([\#11710](https://github.com/matrix-org/synapse/issues/11710), [\#11745](https://github.com/matrix-org/synapse/issues/11745))
- Make the 'List Rooms' Admin API sort stable. Contributed by Daniël Sonck. ([\#11737](https://github.com/matrix-org/synapse/issues/11737))
- Fix a long-standing bug where space hierarchy over federation would only work correctly some of the time. ([\#11775](https://github.com/matrix-org/synapse/issues/11775))
- Fix a bug introduced in Synapse v1.46.0 that prevented `on_logged_out` module callbacks from being correctly awaited by Synapse. ([\#11786](https://github.com/matrix-org/synapse/issues/11786))

Improved Documentation
----------------------

- Warn against using a Let's Encrypt certificate for TLS/DTLS TURN server client connections, and suggest using ZeroSSL certificate instead. This works around client-side connectivity errors caused by WebRTC libraries that reject Let's Encrypt certificates. Contibuted by @AndrewFerr. ([\#11686](https://github.com/matrix-org/synapse/issues/11686))
- Document the new `SYNAPSE_TEST_PERSIST_SQLITE_DB` environment variable in the contributing guide. ([\#11715](https://github.com/matrix-org/synapse/issues/11715))
- Document that the minimum supported PostgreSQL version is now 10. ([\#11725](https://github.com/matrix-org/synapse/issues/11725))
- Fix typo in demo docs: differnt. ([\#11735](https://github.com/matrix-org/synapse/issues/11735))
- Update room spec URL in config files. ([\#11739](https://github.com/matrix-org/synapse/issues/11739))
- Mention `python3-venv` and `libpq-dev` dependencies in the contribution guide. ([\#11740](https://github.com/matrix-org/synapse/issues/11740))
- Update documentation for configuring login with Facebook. ([\#11755](https://github.com/matrix-org/synapse/issues/11755))
- Update installation instructions to note that Python 3.6 is no longer supported. ([\#11781](https://github.com/matrix-org/synapse/issues/11781))

Deprecations and Removals
-------------------------

- Remove the unstable `/send_relation` endpoint. ([\#11682](https://github.com/matrix-org/synapse/issues/11682))
- Remove `python_twisted_reactor_pending_calls` Prometheus metric. ([\#11724](https://github.com/matrix-org/synapse/issues/11724))
- Remove the `password_hash` field from the response dictionaries of the [Users Admin API](https://matrix-org.github.io/synapse/latest/admin_api/user_admin_api.html). ([\#11576](https://github.com/matrix-org/synapse/issues/11576))
- **Deprecate support for `webclient` listeners and non-HTTP(S) `web_client_location` configuration. ([\#11774](https://github.com/matrix-org/synapse/issues/11774), [\#11783](https://github.com/matrix-org/synapse/issues/11783))**

Internal Changes
----------------

- Run `pyupgrade --py37-plus --keep-percent-format` on Synapse. ([\#11685](https://github.com/matrix-org/synapse/issues/11685))
- Use buildkit's cache feature to speed up docker builds. ([\#11691](https://github.com/matrix-org/synapse/issues/11691))
- Use `auto_attribs` and native type hints for attrs classes. ([\#11692](https://github.com/matrix-org/synapse/issues/11692), [\#11768](https://github.com/matrix-org/synapse/issues/11768))
- Remove debug logging for #4422, which has been closed since Synapse 0.99. ([\#11693](https://github.com/matrix-org/synapse/issues/11693))
- Remove fallback code for Python 2. ([\#11699](https://github.com/matrix-org/synapse/issues/11699))
- Add a test for [an edge case](https://github.com/matrix-org/synapse/pull/11532#discussion_r769104461) in the `/sync` logic. ([\#11701](https://github.com/matrix-org/synapse/issues/11701))
- Add the option to write SQLite test dbs to disk when running tests. ([\#11702](https://github.com/matrix-org/synapse/issues/11702))
- Improve Complement test output for Gitub Actions. ([\#11707](https://github.com/matrix-org/synapse/issues/11707))
- Fix docstring on `add_account_data_for_user`. ([\#11716](https://github.com/matrix-org/synapse/issues/11716))
- Complement environment variable name change and update `.gitignore`. ([\#11718](https://github.com/matrix-org/synapse/issues/11718))
- Simplify calculation of Prometheus metrics for garbage collection. ([\#11723](https://github.com/matrix-org/synapse/issues/11723))
- Improve accuracy of `python_twisted_reactor_tick_time` Prometheus metric. ([\#11724](https://github.com/matrix-org/synapse/issues/11724), [\#11771](https://github.com/matrix-org/synapse/issues/11771))
- Minor efficiency improvements when inserting many values into the database. ([\#11742](https://github.com/matrix-org/synapse/issues/11742))
- Invite PR authors to give themselves credit in the changelog. ([\#11744](https://github.com/matrix-org/synapse/issues/11744))
- Add optional debugging to investigate [issue 8631](https://github.com/matrix-org/synapse/issues/8631). ([\#11760](https://github.com/matrix-org/synapse/issues/11760))
- Remove `log_function` utility function and its uses. ([\#11761](https://github.com/matrix-org/synapse/issues/11761))
- Add a unit test that checks both `client` and `webclient` resources will function when simultaneously enabled. ([\#11765](https://github.com/matrix-org/synapse/issues/11765))
- Allow overriding complement commit using `COMPLEMENT_REF`. ([\#11766](https://github.com/matrix-org/synapse/issues/11766))
- Add some comments and type annotations for `_update_outliers_txn`. ([\#11776](https://github.com/matrix-org/synapse/issues/11776))

8 files changed, 99 insertions, 32 deletions

diff --git a/docs/admin_api/user_admin_api.md b/docs/admin_api/user_admin_api.md
index 74933d2fcf..c514cadb9d 100644
--- a/docs/admin_api/user_admin_api.md
+++ b/docs/admin_api/user_admin_api.md
@@ -15,9 +15,10 @@ server admin: [Admin API](../usage/administration/admin_api)
 
 It returns a JSON body like the following:
 
-```json
+```jsonc
 {
-    "displayname": "User",
+    "name": "@user:example.com",
+    "displayname": "User", // can be null if not set
     "threepids": [
         {
             "medium": "email",
@@ -32,11 +33,11 @@ It returns a JSON body like the following:
             "validated_at": 1586458409743
         }
     ],
-    "avatar_url": "<avatar_url>",
+    "avatar_url": "<avatar_url>",  // can be null if not set
+    "is_guest": 0,
     "admin": 0,
     "deactivated": 0,
     "shadow_banned": 0,
-    "password_hash": "$2b$12$p9B4GkqYdRTPGD",
     "creation_ts": 1560432506,
     "appservice_id": null,
     "consent_server_notice_sent": null,
diff --git a/docs/development/contributing_guide.md b/docs/development/contributing_guide.md
index abdb808438..c142981693 100644
--- a/docs/development/contributing_guide.md
+++ b/docs/development/contributing_guide.md
@@ -20,7 +20,9 @@ recommended for development. More information about WSL can be found at
 <https://docs.microsoft.com/en-us/windows/wsl/install>. Running Synapse natively
 on Windows is not officially supported.
 
-The code of Synapse is written in Python 3. To do pretty much anything, you'll need [a recent version of Python 3](https://wiki.python.org/moin/BeginnersGuide/Download).
+The code of Synapse is written in Python 3. To do pretty much anything, you'll need [a recent version of Python 3](https://www.python.org/downloads/). Your Python also needs support for [virtual environments](https://docs.python.org/3/library/venv.html). This is usually built-in, but some Linux distributions like Debian and Ubuntu split it out into its own package. Running `sudo apt install python3-venv` should be enough.
+
+Synapse can connect to PostgreSQL via the [psycopg2](https://pypi.org/project/psycopg2/) Python library. Building this library from source requires access to PostgreSQL's C header files. On Debian or Ubuntu Linux, these can be installed with `sudo apt install libpq-dev`.
 
 The source code of Synapse is hosted on GitHub. You will also need [a recent version of git](https://github.com/git-guides/install-git).
 
@@ -169,6 +171,27 @@ To increase the log level for the tests, set `SYNAPSE_TEST_LOG_LEVEL`:
 SYNAPSE_TEST_LOG_LEVEL=DEBUG trial tests
 ```
 
+By default, tests will use an in-memory SQLite database for test data. For additional
+help with debugging, one can use an on-disk SQLite database file instead, in order to
+review database state during and after running tests. This can be done by setting
+the `SYNAPSE_TEST_PERSIST_SQLITE_DB` environment variable. Doing so will cause the
+database state to be stored in a file named `test.db` under the trial process'
+working directory. Typically, this ends up being `_trial_temp/test.db`. For example:
+
+```sh
+SYNAPSE_TEST_PERSIST_SQLITE_DB=1 trial tests
+```
+
+The database file can then be inspected with:
+
+```sh
+sqlite3 _trial_temp/test.db
+```
+
+Note that the database file is cleared at the beginning of each test run. Thus it 
+will always only contain the data generated by the *last run test*. Though generally
+when debugging, one is only running a single test anyway.
+
 ### Running tests under PostgreSQL
 
 Invoking `trial` as above will use an in-memory SQLite database. This is great for
diff --git a/docs/development/url_previews.md b/docs/development/url_previews.md
index aff3813609..154b9a5e12 100644
--- a/docs/development/url_previews.md
+++ b/docs/development/url_previews.md
@@ -35,7 +35,12 @@ When Synapse is asked to preview a URL it does the following:
    5. If the media is HTML:
       1. Decodes the HTML via the stored file.
       2. Generates an Open Graph response from the HTML.
-      3. If an image exists in the Open Graph response:
+      3. If a JSON oEmbed URL was found in the HTML via autodiscovery:
+         1. Downloads the URL and stores it into a file via the media storage provider
+            and saves the local media metadata.
+         2. Convert the oEmbed response to an Open Graph response.
+         3. Override any Open Graph data from the HTML with data from oEmbed.
+      4. If an image exists in the Open Graph response:
          1. Downloads the URL and stores it into a file via the media storage
             provider and saves the local media metadata.
          2. Generates thumbnails.
diff --git a/docs/openid.md b/docs/openid.md
index ff9de9d5b8..171ea3b712 100644
--- a/docs/openid.md
+++ b/docs/openid.md
@@ -390,9 +390,6 @@ oidc_providers:
 
 ### Facebook
 
-Like Github, Facebook provide a custom OAuth2 API rather than an OIDC-compliant
-one so requires a little more configuration.
-
 0. You will need a Facebook developer account. You can register for one
    [here](https://developers.facebook.com/async/registration/).
 1. On the [apps](https://developers.facebook.com/apps/) page of the developer
@@ -412,24 +409,28 @@ Synapse config:
     idp_name: Facebook
     idp_brand: "facebook"  # optional: styling hint for clients
     discover: false
-    issuer: "https://facebook.com"
+    issuer: "https://www.facebook.com"
     client_id: "your-client-id" # TO BE FILLED
     client_secret: "your-client-secret" # TO BE FILLED
     scopes: ["openid", "email"]
-    authorization_endpoint: https://facebook.com/dialog/oauth
-    token_endpoint: https://graph.facebook.com/v9.0/oauth/access_token
-    user_profile_method: "userinfo_endpoint"
-    userinfo_endpoint: "https://graph.facebook.com/v9.0/me?fields=id,name,email,picture"
+    authorization_endpoint: "https://facebook.com/dialog/oauth"
+    token_endpoint: "https://graph.facebook.com/v9.0/oauth/access_token"
+    jwks_uri: "https://www.facebook.com/.well-known/oauth/openid/jwks/"
     user_mapping_provider:
       config:
-        subject_claim: "id"
         display_name_template: "{{ user.name }}"
+        email_template: "{{ '{{ user.email }}' }}"
 ```
 
 Relevant documents:
- * https://developers.facebook.com/docs/facebook-login/manually-build-a-login-flow
- * Using Facebook's Graph API: https://developers.facebook.com/docs/graph-api/using-graph-api/
- * Reference to the User endpoint: https://developers.facebook.com/docs/graph-api/reference/user
+ * [Manually Build a Login Flow](https://developers.facebook.com/docs/facebook-login/manually-build-a-login-flow)
+ * [Using Facebook's Graph API](https://developers.facebook.com/docs/graph-api/using-graph-api/)
+ * [Reference to the User endpoint](https://developers.facebook.com/docs/graph-api/reference/user)
+
+Facebook do have an [OIDC discovery endpoint](https://www.facebook.com/.well-known/openid-configuration),
+but it has a `response_types_supported` which excludes "code" (which we rely on, and
+is even mentioned in their [documentation](https://developers.facebook.com/docs/facebook-login/manually-build-a-login-flow#login)),
+so we have to disable discovery and configure the URIs manually.
 
 ### Gitea
 
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index 810a14b077..1b86d0295d 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -74,13 +74,7 @@ server_name: "SERVERNAME"
 #
 pid_file: DATADIR/homeserver.pid
 
-# The absolute URL to the web client which /_matrix/client will redirect
-# to if 'webclient' is configured under the 'listeners' configuration.
-#
-# This option can be also set to the filesystem path to the web client
-# which will be served at /_matrix/client/ if 'webclient' is configured
-# under the 'listeners' configuration, however this is a security risk:
-# https://github.com/matrix-org/synapse#security-note
+# The absolute URL to the web client which / will redirect to.
 #
 #web_client_location: https://riot.example.com/
 
@@ -164,7 +158,7 @@ presence:
 # The default room version for newly created rooms.
 #
 # Known room versions are listed here:
-# https://matrix.org/docs/spec/#complete-list-of-room-versions
+# https://spec.matrix.org/latest/rooms/#complete-list-of-room-versions
 #
 # For example, for room version 1, default_room_version should be set
 # to "1".
@@ -310,8 +304,6 @@ presence:
 #   static: static resources under synapse/static (/_matrix/static). (Mostly
 #       useful for 'fallback authentication'.)
 #
-#   webclient: A web client. Requires web_client_location to be set.
-#
 listeners:
   # TLS-enabled listener: for when matrix traffic is sent directly to synapse.
   #
@@ -1503,6 +1495,21 @@ room_prejoin_state:
    #additional_event_types:
    #  - org.example.custom.event.type
 
+# We record the IP address of clients used to access the API for various
+# reasons, including displaying it to the user in the "Where you're signed in"
+# dialog.
+#
+# By default, when puppeting another user via the admin API, the client IP
+# address is recorded against the user who created the access token (ie, the
+# admin user), and *not* the puppeted user.
+#
+# Uncomment the following to also record the IP address against the puppeted
+# user. (This also means that the puppeted user will count as an "active" user
+# for the purpose of monthly active user tracking - see 'limit_usage_by_mau' etc
+# above.)
+#
+#track_puppeted_user_ips: true
+
 
 # A list of application service config files to use
 #
@@ -1870,10 +1877,13 @@ saml2_config:
 #       Defaults to false. Avoid this in production.
 #
 #   user_profile_method: Whether to fetch the user profile from the userinfo
-#       endpoint. Valid values are: 'auto' or 'userinfo_endpoint'.
+#       endpoint, or to rely on the data returned in the id_token from the
+#       token_endpoint.
+#
+#       Valid values are: 'auto' or 'userinfo_endpoint'.
 #
-#       Defaults to 'auto', which fetches the userinfo endpoint if 'openid' is
-#       included in 'scopes'. Set to 'userinfo_endpoint' to always fetch the
+#       Defaults to 'auto', which uses the userinfo endpoint if 'openid' is
+#       not included in 'scopes'. Set to 'userinfo_endpoint' to always use the
 #       userinfo endpoint.
 #
 #   allow_existing_users: set to 'true' to allow a user logging in via OIDC to
diff --git a/docs/setup/installation.md b/docs/setup/installation.md
index 210c80dace..fe657a15df 100644
--- a/docs/setup/installation.md
+++ b/docs/setup/installation.md
@@ -194,7 +194,7 @@ When following this route please make sure that the [Platform-specific prerequis
 System requirements:
 
 - POSIX-compliant system (tested on Linux & OS X)
-- Python 3.6 or later, up to Python 3.9.
+- Python 3.7 or later, up to Python 3.9.
 - At least 1GB of free RAM if you want to join large public rooms like #matrix:matrix.org
 
 To install the Synapse homeserver run:
diff --git a/docs/turn-howto.md b/docs/turn-howto.md
index e32aaa1850..eba7ca6124 100644
--- a/docs/turn-howto.md
+++ b/docs/turn-howto.md
@@ -137,6 +137,10 @@ This will install and start a systemd service called `coturn`.
 
     # TLS private key file
     pkey=/path/to/privkey.pem
+
+    # Ensure the configuration lines that disable TLS/DTLS are commented-out or removed
+    #no-tls
+    #no-dtls
     ```
 
     In this case, replace the `turn:` schemes in the `turn_uris` settings below
@@ -145,6 +149,14 @@ This will install and start a systemd service called `coturn`.
     We recommend that you only try to set up TLS/DTLS once you have set up a
     basic installation and got it working.
 
+    NB: If your TLS certificate was provided by Let's Encrypt, TLS/DTLS will
+    not work with any Matrix client that uses Chromium's WebRTC library. This
+    currently includes Element Android & iOS; for more details, see their
+    [respective](https://github.com/vector-im/element-android/issues/1533)
+    [issues](https://github.com/vector-im/element-ios/issues/2712) as well as the underlying
+    [WebRTC issue](https://bugs.chromium.org/p/webrtc/issues/detail?id=11710).
+    Consider using a ZeroSSL certificate for your TURN server as a working alternative.
+
 1.  Ensure your firewall allows traffic into the TURN server on the ports
     you've configured it to listen on (By default: 3478 and 5349 for TURN
     traffic (remember to allow both TCP and UDP traffic), and ports 49152-65535
@@ -250,6 +262,10 @@ Here are a few things to try:
  * Check that you have opened your firewall to allow UDP traffic to the UDP
    relay ports (49152-65535 by default).
 
+ * Try disabling `coturn`'s TLS/DTLS listeners and enable only its (unencrypted)
+   TCP/UDP listeners. (This will only leave signaling traffic unencrypted;
+   voice & video WebRTC traffic is always encrypted.)
+
  * Some WebRTC implementations (notably, that of Google Chrome) appear to get
    confused by TURN servers which are reachable over IPv6 (this appears to be
    an unexpected side-effect of its handling of multiple IP addresses as
diff --git a/docs/upgrade.md b/docs/upgrade.md
index 30bb0dcd9c..f455d257ba 100644
--- a/docs/upgrade.md
+++ b/docs/upgrade.md
@@ -85,6 +85,17 @@ process, for example:
     dpkg -i matrix-synapse-py3_1.3.0+stretch1_amd64.deb
     ```
 
+# Upgrading to v1.51.0
+
+## Deprecation of `webclient` listeners and non-HTTP(S) `web_client_location`
+
+Listeners of type  `webclient` are deprecated and scheduled to be removed in
+Synapse v1.53.0.
+
+Similarly, a non-HTTP(S) `web_client_location` configuration is deprecated and
+will become a configuration error in Synapse v1.53.0.
+
+
 # Upgrading to v1.50.0
 
 ## Dropping support for old Python and Postgres versions