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authorAndrew Morgan <andrew@amorgan.xyz>2019-10-03 13:48:21 +0100
committerAndrew Morgan <andrew@amorgan.xyz>2019-10-03 13:48:21 +0100
commit782dd72037cf71fb3f9e4922b07c56df2f59de75 (patch)
treed8d74a1d411cd83a762880715f47b2f33351994a /docs/code_style.md
parentUpdate the issue template for new way of getting server version (#6051) (diff)
parent1.4.0 (diff)
downloadsynapse-782dd72037cf71fb3f9e4922b07c56df2f59de75.tar.xz
Merge tag 'v1.4.0'
Synapse 1.4.0 (2019-10-03)
==========================

Bugfixes
--------

- Redact `client_secret` in server logs. ([\#6158](https://github.com/matrix-org/synapse/issues/6158))

Synapse 1.4.0rc2 (2019-10-02)
=============================

Bugfixes
--------

- Fix bug in background update that adds last seen information to the `devices` table, and improve its performance on Postgres. ([\#6135](https://github.com/matrix-org/synapse/issues/6135))
- Fix bad performance of censoring redactions background task. ([\#6141](https://github.com/matrix-org/synapse/issues/6141))
- Fix fetching censored redactions from DB, which caused APIs like initial sync to fail if it tried to include the censored redaction. ([\#6145](https://github.com/matrix-org/synapse/issues/6145))
- Fix exceptions when storing large retry intervals for down remote servers. ([\#6146](https://github.com/matrix-org/synapse/issues/6146))

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

- Fix up sample config entry for `redaction_retention_period` option. ([\#6117](https://github.com/matrix-org/synapse/issues/6117))

Synapse 1.4.0rc1 (2019-09-26)
=============================

Note that this release includes significant changes around 3pid
verification. Administrators are reminded to review the [upgrade notes](UPGRADE.rst#upgrading-to-v140).

Features
--------

- Changes to 3pid verification:
  - Add the ability to send registration emails from the homeserver rather than delegating to an identity server. ([\#5835](https://github.com/matrix-org/synapse/issues/5835), [\#5940](https://github.com/matrix-org/synapse/issues/5940), [\#5993](https://github.com/matrix-org/synapse/issues/5993), [\#5994](https://github.com/matrix-org/synapse/issues/5994), [\#5868](https://github.com/matrix-org/synapse/issues/5868))
  - Replace `trust_identity_server_for_password_resets` config option with `account_threepid_delegates`, and make the `id_server` parameteter optional on `*/requestToken` endpoints, as per [MSC2263](https://github.com/matrix-org/matrix-doc/pull/2263). ([\#5876](https://github.com/matrix-org/synapse/issues/5876), [\#5969](https://github.com/matrix-org/synapse/issues/5969), [\#6028](https://github.com/matrix-org/synapse/issues/6028))
  - Switch to using the v2 Identity Service `/lookup` API where available, with fallback to v1. (Implements [MSC2134](https://github.com/matrix-org/matrix-doc/pull/2134) plus `id_access_token authentication` for v2 Identity Service APIs from [MSC2140](https://github.com/matrix-org/matrix-doc/pull/2140)). ([\#5897](https://github.com/matrix-org/synapse/issues/5897))
  - Remove `bind_email` and `bind_msisdn` parameters from `/register` ala [MSC2140](https://github.com/matrix-org/matrix-doc/pull/2140). ([\#5964](https://github.com/matrix-org/synapse/issues/5964))
  - Add `m.id_access_token` to `unstable_features` in `/versions` as per [MSC2264](https://github.com/matrix-org/matrix-doc/pull/2264). ([\#5974](https://github.com/matrix-org/synapse/issues/5974))
  - Use the v2 Identity Service API for 3PID invites. ([\#5979](https://github.com/matrix-org/synapse/issues/5979))
  - Add `POST /_matrix/client/unstable/account/3pid/unbind` endpoint from [MSC2140](https://github.com/matrix-org/matrix-doc/pull/2140) for unbinding a 3PID from an identity server without removing it from the homeserver user account. ([\#5980](https://github.com/matrix-org/synapse/issues/5980), [\#6062](https://github.com/matrix-org/synapse/issues/6062))
  - Use `account_threepid_delegate.email` and `account_threepid_delegate.msisdn` for validating threepid sessions. ([\#6011](https://github.com/matrix-org/synapse/issues/6011))
  - Allow homeserver to handle or delegate email validation when adding an email to a user's account. ([\#6042](https://github.com/matrix-org/synapse/issues/6042))
  - Implement new Client Server API endpoints `/account/3pid/add` and `/account/3pid/bind` as per [MSC2290](https://github.com/matrix-org/matrix-doc/pull/2290). ([\#6043](https://github.com/matrix-org/synapse/issues/6043))
  - Add an unstable feature flag for separate add/bind 3pid APIs. ([\#6044](https://github.com/matrix-org/synapse/issues/6044))
  - Remove `bind` parameter from Client Server POST `/account` endpoint as per [MSC2290](https://github.com/matrix-org/matrix-doc/pull/2290/). ([\#6067](https://github.com/matrix-org/synapse/issues/6067))
  - Add `POST /add_threepid/msisdn/submit_token` endpoint for proxying submitToken on an `account_threepid_handler`. ([\#6078](https://github.com/matrix-org/synapse/issues/6078))
  - Add `submit_url` response parameter to `*/msisdn/requestToken` endpoints. ([\#6079](https://github.com/matrix-org/synapse/issues/6079))
  - Add `m.require_identity_server` flag to /version's unstable_features. ([\#5972](https://github.com/matrix-org/synapse/issues/5972))
- Enhancements to OpenTracing support:
  - Make OpenTracing work in worker mode. ([\#5771](https://github.com/matrix-org/synapse/issues/5771))
  - Pass OpenTracing contexts between servers when transmitting EDUs. ([\#5852](https://github.com/matrix-org/synapse/issues/5852))
  - OpenTracing for device list updates. ([\#5853](https://github.com/matrix-org/synapse/issues/5853))
  - Add a tag recording a request's authenticated entity and corresponding servlet in OpenTracing. ([\#5856](https://github.com/matrix-org/synapse/issues/5856))
  - Add minimum OpenTracing for client servlets. ([\#5983](https://github.com/matrix-org/synapse/issues/5983))
  - Check at setup that OpenTracing is installed if it's enabled in the config. ([\#5985](https://github.com/matrix-org/synapse/issues/5985))
  - Trace replication send times. ([\#5986](https://github.com/matrix-org/synapse/issues/5986))
  - Include missing OpenTracing contexts in outbout replication requests. ([\#5982](https://github.com/matrix-org/synapse/issues/5982))
  - Fix sending of EDUs when OpenTracing is enabled with an empty whitelist. ([\#5984](https://github.com/matrix-org/synapse/issues/5984))
  - Fix invalid references to None while OpenTracing if the log context slips. ([\#5988](https://github.com/matrix-org/synapse/issues/5988), [\#5991](https://github.com/matrix-org/synapse/issues/5991))
  - OpenTracing for room and e2e keys. ([\#5855](https://github.com/matrix-org/synapse/issues/5855))
  - Add OpenTracing span over HTTP push processing. ([\#6003](https://github.com/matrix-org/synapse/issues/6003))
- Add an admin API to purge old rooms from the database. ([\#5845](https://github.com/matrix-org/synapse/issues/5845))
- Retry well-known lookups if we have recently seen a valid well-known record for the server. ([\#5850](https://github.com/matrix-org/synapse/issues/5850))
- Add support for filtered room-directory search requests over federation ([MSC2197](https://github.com/matrix-org/matrix-doc/pull/2197), in order to allow upcoming room directory query performance improvements. ([\#5859](https://github.com/matrix-org/synapse/issues/5859))
- Correctly retry all hosts returned from SRV when we fail to connect. ([\#5864](https://github.com/matrix-org/synapse/issues/5864))
- Add admin API endpoint for setting whether or not a user is a server administrator. ([\#5878](https://github.com/matrix-org/synapse/issues/5878))
- Enable cleaning up extremities with dummy events by default to prevent undue build up of forward extremities. ([\#5884](https://github.com/matrix-org/synapse/issues/5884))
- Add config option to sign remote key query responses with a separate key. ([\#5895](https://github.com/matrix-org/synapse/issues/5895))
- Add support for config templating. ([\#5900](https://github.com/matrix-org/synapse/issues/5900))
- Users with the type of "support" or "bot" are no longer required to consent. ([\#5902](https://github.com/matrix-org/synapse/issues/5902))
- Let synctl accept a directory of config files. ([\#5904](https://github.com/matrix-org/synapse/issues/5904))
- Increase max display name size to 256. ([\#5906](https://github.com/matrix-org/synapse/issues/5906))
- Add admin API endpoint for getting whether or not a user is a server administrator. ([\#5914](https://github.com/matrix-org/synapse/issues/5914))
- Redact events in the database that have been redacted for a week. ([\#5934](https://github.com/matrix-org/synapse/issues/5934))
- New prometheus metrics:
  - `synapse_federation_known_servers`: represents the total number of servers your server knows about (i.e. is in rooms with), including itself. Enable by setting `metrics_flags.known_servers` to True in the configuration.([\#5981](https://github.com/matrix-org/synapse/issues/5981))
  - `synapse_build_info`: exposes the Python version, OS version, and Synapse version of the running server. ([\#6005](https://github.com/matrix-org/synapse/issues/6005))
- Give appropriate exit codes when synctl fails. ([\#5992](https://github.com/matrix-org/synapse/issues/5992))
- Apply the federation blacklist to requests to identity servers. ([\#6000](https://github.com/matrix-org/synapse/issues/6000))
- Add `report_stats_endpoint` option to configure where stats are reported to, if enabled. Contributed by @Sorunome. ([\#6012](https://github.com/matrix-org/synapse/issues/6012))
- Add config option to increase ratelimits for room admins redacting messages. ([\#6015](https://github.com/matrix-org/synapse/issues/6015))
- Stop sending federation transactions to servers which have been down for a long time. ([\#6026](https://github.com/matrix-org/synapse/issues/6026))
- Make the process for mapping SAML2 users to matrix IDs more flexible. ([\#6037](https://github.com/matrix-org/synapse/issues/6037))
- Return a clearer error message when a timeout occurs when attempting to contact an identity server. ([\#6073](https://github.com/matrix-org/synapse/issues/6073))
- Prevent password reset's submit_token endpoint from accepting trailing slashes. ([\#6074](https://github.com/matrix-org/synapse/issues/6074))
- Return 403 on `/register/available` if registration has been disabled. ([\#6082](https://github.com/matrix-org/synapse/issues/6082))
- Explicitly log when a homeserver does not have the `trusted_key_servers` config field configured. ([\#6090](https://github.com/matrix-org/synapse/issues/6090))
- Add support for pruning old rows in `user_ips` table. ([\#6098](https://github.com/matrix-org/synapse/issues/6098))

Bugfixes
--------

- Don't create broken room when `power_level_content_override.users` does not contain `creator_id`. ([\#5633](https://github.com/matrix-org/synapse/issues/5633))
- Fix database index so that different backup versions can have the same sessions. ([\#5857](https://github.com/matrix-org/synapse/issues/5857))
- Fix Synapse looking for config options `password_reset_failure_template` and `password_reset_success_template`, when they are actually `password_reset_template_failure_html`, `password_reset_template_success_html`. ([\#5863](https://github.com/matrix-org/synapse/issues/5863))
- Fix stack overflow when recovering an appservice which had an outage. ([\#5885](https://github.com/matrix-org/synapse/issues/5885))
- Fix error message which referred to `public_base_url` instead of `public_baseurl`. Thanks to @aaronraimist for the fix! ([\#5909](https://github.com/matrix-org/synapse/issues/5909))
- Fix 404 for thumbnail download when `dynamic_thumbnails` is `false` and the thumbnail was dynamically generated. Fix reported by rkfg. ([\#5915](https://github.com/matrix-org/synapse/issues/5915))
- Fix a cache-invalidation bug for worker-based deployments. ([\#5920](https://github.com/matrix-org/synapse/issues/5920))
- Fix admin API for listing media in a room not being available with an external media repo. ([\#5966](https://github.com/matrix-org/synapse/issues/5966))
- Fix list media admin API always returning an error. ([\#5967](https://github.com/matrix-org/synapse/issues/5967))
- Fix room and user stats tracking. ([\#5971](https://github.com/matrix-org/synapse/issues/5971), [\#5998](https://github.com/matrix-org/synapse/issues/5998), [\#6029](https://github.com/matrix-org/synapse/issues/6029))
- Return a `M_MISSING_PARAM` if `sid` is not provided to `/account/3pid`. ([\#5995](https://github.com/matrix-org/synapse/issues/5995))
- `federation_certificate_verification_whitelist` now will not cause `TypeErrors` to be raised (a regression in 1.3). Additionally, it now supports internationalised domain names in their non-canonical representation. ([\#5996](https://github.com/matrix-org/synapse/issues/5996))
- Only count real users when checking for auto-creation of auto-join room. ([\#6004](https://github.com/matrix-org/synapse/issues/6004))
- Ensure support users can be registered even if MAU limit is reached. ([\#6020](https://github.com/matrix-org/synapse/issues/6020))
- Fix bug where login error was shown incorrectly on SSO fallback login. ([\#6024](https://github.com/matrix-org/synapse/issues/6024))
- Fix bug in calculating the federation retry backoff period. ([\#6025](https://github.com/matrix-org/synapse/issues/6025))
- Prevent exceptions being logged when extremity-cleanup events fail due to lack of user consent to the terms of service. ([\#6053](https://github.com/matrix-org/synapse/issues/6053))
- Remove POST method from password-reset `submit_token` endpoint until we implement `submit_url` functionality. ([\#6056](https://github.com/matrix-org/synapse/issues/6056))
- Fix logcontext spam on non-Linux platforms. ([\#6059](https://github.com/matrix-org/synapse/issues/6059))
- Ensure query parameters in email validation links are URL-encoded. ([\#6063](https://github.com/matrix-org/synapse/issues/6063))
- Fix a bug which caused SAML attribute maps to be overridden by defaults. ([\#6069](https://github.com/matrix-org/synapse/issues/6069))
- Fix the logged number of updated items for the `users_set_deactivated_flag` background update. ([\#6092](https://github.com/matrix-org/synapse/issues/6092))
- Add `sid` to `next_link` for email validation. ([\#6097](https://github.com/matrix-org/synapse/issues/6097))
- Threepid validity checks on msisdns should not be dependent on `threepid_behaviour_email`. ([\#6104](https://github.com/matrix-org/synapse/issues/6104))
- Ensure that servers which are not configured to support email address verification do not offer it in the registration flows. ([\#6107](https://github.com/matrix-org/synapse/issues/6107))

Updates to the Docker image
---------------------------

- Avoid changing `UID/GID` if they are already correct. ([\#5970](https://github.com/matrix-org/synapse/issues/5970))
- Provide `SYNAPSE_WORKER` envvar to specify python module. ([\#6058](https://github.com/matrix-org/synapse/issues/6058))

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

- Convert documentation to markdown (from rst) ([\#5849](https://github.com/matrix-org/synapse/issues/5849))
- Update `INSTALL.md` to say that Python 2 is no longer supported. ([\#5953](https://github.com/matrix-org/synapse/issues/5953))
- Add developer documentation for using SAML2. ([\#6032](https://github.com/matrix-org/synapse/issues/6032))
- Add some notes on rolling back to v1.3.1. ([\#6049](https://github.com/matrix-org/synapse/issues/6049))
- Update the upgrade notes. ([\#6050](https://github.com/matrix-org/synapse/issues/6050))

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

- Remove shared-secret registration from `/_matrix/client/r0/register` endpoint. Contributed by Awesome Technologies Innovationslabor GmbH. ([\#5877](https://github.com/matrix-org/synapse/issues/5877))
- Deprecate the `trusted_third_party_id_servers` option. ([\#5875](https://github.com/matrix-org/synapse/issues/5875))

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

- Lay the groundwork for structured logging output. ([\#5680](https://github.com/matrix-org/synapse/issues/5680))
- Retry well-known lookup before the cache expires, giving a grace period where the remote well-known can be down but we still use the old result. ([\#5844](https://github.com/matrix-org/synapse/issues/5844))
- Remove log line for debugging issue #5407. ([\#5860](https://github.com/matrix-org/synapse/issues/5860))
- Refactor the Appservice scheduler code. ([\#5886](https://github.com/matrix-org/synapse/issues/5886))
- Compatibility with v2 Identity Service APIs other than /lookup. ([\#5892](https://github.com/matrix-org/synapse/issues/5892), [\#6013](https://github.com/matrix-org/synapse/issues/6013))
- Stop populating some unused tables. ([\#5893](https://github.com/matrix-org/synapse/issues/5893), [\#6047](https://github.com/matrix-org/synapse/issues/6047))
- Add missing index on `users_in_public_rooms` to improve the performance of directory queries. ([\#5894](https://github.com/matrix-org/synapse/issues/5894))
- Improve the logging when we have an error when fetching signing keys. ([\#5896](https://github.com/matrix-org/synapse/issues/5896))
- Add support for database engine-specific schema deltas, based on file extension. ([\#5911](https://github.com/matrix-org/synapse/issues/5911))
- Update Buildkite pipeline to use plugins instead of buildkite-agent commands. ([\#5922](https://github.com/matrix-org/synapse/issues/5922))
- Add link in sample config to the logging config schema. ([\#5926](https://github.com/matrix-org/synapse/issues/5926))
- Remove unnecessary parentheses in return statements. ([\#5931](https://github.com/matrix-org/synapse/issues/5931))
- Remove unused `jenkins/prepare_sytest.sh` file. ([\#5938](https://github.com/matrix-org/synapse/issues/5938))
- Move Buildkite pipeline config to the pipelines repo. ([\#5943](https://github.com/matrix-org/synapse/issues/5943))
- Remove unnecessary return statements in the codebase which were the result of a regex run. ([\#5962](https://github.com/matrix-org/synapse/issues/5962))
- Remove left-over methods from v1 registration API. ([\#5963](https://github.com/matrix-org/synapse/issues/5963))
- Cleanup event auth type initialisation. ([\#5975](https://github.com/matrix-org/synapse/issues/5975))
- Clean up dependency checking at setup. ([\#5989](https://github.com/matrix-org/synapse/issues/5989))
- Update OpenTracing docs to use the unified `trace` method. ([\#5776](https://github.com/matrix-org/synapse/issues/5776))
- Small refactor of function arguments and docstrings in` RoomMemberHandler`. ([\#6009](https://github.com/matrix-org/synapse/issues/6009))
- Remove unused `origin` argument on `FederationHandler.add_display_name_to_third_party_invite`. ([\#6010](https://github.com/matrix-org/synapse/issues/6010))
- Add a `failure_ts` column to the `destinations` database table. ([\#6016](https://github.com/matrix-org/synapse/issues/6016), [\#6072](https://github.com/matrix-org/synapse/issues/6072))
- Clean up some code in the retry logic. ([\#6017](https://github.com/matrix-org/synapse/issues/6017))
- Fix the structured logging tests stomping on the global log configuration for subsequent tests. ([\#6023](https://github.com/matrix-org/synapse/issues/6023))
- Clean up the sample config for SAML authentication. ([\#6064](https://github.com/matrix-org/synapse/issues/6064))
- Change mailer logging to reflect Synapse doesn't just do chat notifications by email now. ([\#6075](https://github.com/matrix-org/synapse/issues/6075))
- Move last-seen info into devices table. ([\#6089](https://github.com/matrix-org/synapse/issues/6089))
- Remove unused parameter to `get_user_id_by_threepid`. ([\#6099](https://github.com/matrix-org/synapse/issues/6099))
- Refactor the user-interactive auth handling. ([\#6105](https://github.com/matrix-org/synapse/issues/6105))
- Refactor code for calculating registration flows. ([\#6106](https://github.com/matrix-org/synapse/issues/6106))
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diff --git a/docs/code_style.md b/docs/code_style.md
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@@ -0,0 +1,169 @@
+# Code Style
+
+## Formatting tools
+
+The Synapse codebase uses a number of code formatting tools in order to
+quickly and automatically check for formatting (and sometimes logical)
+errors in code.
+
+The necessary tools are detailed below.
+
+-   **black**
+
+    The Synapse codebase uses [black](https://pypi.org/project/black/)
+    as an opinionated code formatter, ensuring all comitted code is
+    properly formatted.
+
+    First install `black` with:
+
+        pip install --upgrade black
+
+    Have `black` auto-format your code (it shouldn't change any
+    functionality) with:
+
+        black . --exclude="\.tox|build|env"
+
+-   **flake8**
+
+    `flake8` is a code checking tool. We require code to pass `flake8`
+    before being merged into the codebase.
+
+    Install `flake8` with:
+
+        pip install --upgrade flake8
+
+    Check all application and test code with:
+
+        flake8 synapse tests
+
+-   **isort**
+
+    `isort` ensures imports are nicely formatted, and can suggest and
+    auto-fix issues such as double-importing.
+
+    Install `isort` with:
+
+        pip install --upgrade isort
+
+    Auto-fix imports with:
+
+        isort -rc synapse tests
+
+    `-rc` means to recursively search the given directories.
+
+It's worth noting that modern IDEs and text editors can run these tools
+automatically on save. It may be worth looking into whether this
+functionality is supported in your editor for a more convenient
+development workflow. It is not, however, recommended to run `flake8` on
+save as it takes a while and is very resource intensive.
+
+## General rules
+
+-   **Naming**:
+    -   Use camel case for class and type names
+    -   Use underscores for functions and variables.
+-   **Docstrings**: should follow the [google code
+    style](https://google.github.io/styleguide/pyguide.html#38-comments-and-docstrings).
+    This is so that we can generate documentation with
+    [sphinx](http://sphinxcontrib-napoleon.readthedocs.org/en/latest/).
+    See the
+    [examples](http://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html)
+    in the sphinx documentation.
+-   **Imports**:
+    -   Imports should be sorted by `isort` as described above.
+    -   Prefer to import classes and functions rather than packages or
+        modules.
+
+        Example:
+
+            from synapse.types import UserID
+            ...
+            user_id = UserID(local, server)
+
+        is preferred over:
+
+            from synapse import types
+            ...
+            user_id = types.UserID(local, server)
+
+        (or any other variant).
+
+        This goes against the advice in the Google style guide, but it
+        means that errors in the name are caught early (at import time).
+
+    -   Avoid wildcard imports (`from synapse.types import *`) and
+        relative imports (`from .types import UserID`).
+
+## Configuration file format
+
+The [sample configuration file](./sample_config.yaml) acts as a
+reference to Synapse's configuration options for server administrators.
+Remember that many readers will be unfamiliar with YAML and server
+administration in general, so that it is important that the file be as
+easy to understand as possible, which includes following a consistent
+format.
+
+Some guidelines follow:
+
+-   Sections should be separated with a heading consisting of a single
+    line prefixed and suffixed with `##`. There should be **two** blank
+    lines before the section header, and **one** after.
+-   Each option should be listed in the file with the following format:
+    -   A comment describing the setting. Each line of this comment
+        should be prefixed with a hash (`#`) and a space.
+
+        The comment should describe the default behaviour (ie, what
+        happens if the setting is omitted), as well as what the effect
+        will be if the setting is changed.
+
+        Often, the comment end with something like "uncomment the
+        following to <do action>".
+
+    -   A line consisting of only `#`.
+    -   A commented-out example setting, prefixed with only `#`.
+
+        For boolean (on/off) options, convention is that this example
+        should be the *opposite* to the default (so the comment will end
+        with "Uncomment the following to enable [or disable]
+        <feature>." For other options, the example should give some
+        non-default value which is likely to be useful to the reader.
+
+-   There should be a blank line between each option.
+-   Where several settings are grouped into a single dict, *avoid* the
+    convention where the whole block is commented out, resulting in
+    comment lines starting `# #`, as this is hard to read and confusing
+    to edit. Instead, leave the top-level config option uncommented, and
+    follow the conventions above for sub-options. Ensure that your code
+    correctly handles the top-level option being set to `None` (as it
+    will be if no sub-options are enabled).
+-   Lines should be wrapped at 80 characters.
+
+Example:
+
+    ## Frobnication ##
+
+    # The frobnicator will ensure that all requests are fully frobnicated.
+    # To enable it, uncomment the following.
+    #
+    #frobnicator_enabled: true
+
+    # By default, the frobnicator will frobnicate with the default frobber.
+    # The following will make it use an alternative frobber.
+    #
+    #frobincator_frobber: special_frobber
+
+    # Settings for the frobber
+    #
+    frobber:
+       # frobbing speed. Defaults to 1.
+       #
+       #speed: 10
+
+       # frobbing distance. Defaults to 1000.
+       #
+       #distance: 100
+
+Note that the sample configuration is generated from the synapse code
+and is maintained by a script, `scripts-dev/generate_sample_config`.
+Making sure that the output from this script matches the desired format
+is left as an exercise for the reader!