v1.2.0rc1

Features
--------

- Add support for opentracing. ([\#5544](#5544), [\#5712](#5712))
- Add ability to pull all locally stored events out of synapse that a particular user can see. ([\#5589](#5589))
- Add a basic admin command app to allow server operators to run Synapse admin commands separately from the main production instance. ([\#5597](#5597))
- Add `sender` and `origin_server_ts` fields to `m.replace`. ([\#5613](#5613))
- Add default push rule to ignore reactions. ([\#5623](#5623))
- Include the original event when asking for its relations. ([\#5626](#5626))
- Implement `session_lifetime` configuration option, after which access tokens will expire. ([\#5660](#5660))
- Return "This account has been deactivated" when a deactivated user tries to login. ([\#5674](#5674))
- Enable aggregations support by default ([\#5714](#5714))

Bugfixes
--------

- Fix 'utime went backwards' errors on daemonization. ([\#5609](#5609))
- Various minor fixes to the federation request rate limiter. ([\#5621](#5621))
- Forbid viewing relations on an event once it has been redacted. ([\#5629](#5629))
- Fix requests to the `/store_invite` endpoint of identity servers being sent in the wrong format. ([\#5638](#5638))
- Fix newly-registered users not being able to lookup their own profile without joining a room. ([\#5644](#5644))
- Fix bug in #5626 that prevented the original_event field from actually having the contents of the original event in a call to `/relations`. ([\#5654](#5654))
- Fix 3PID bind requests being sent to identity servers as `application/x-form-www-urlencoded` data, which is deprecated. ([\#5658](#5658))
- Fix some problems with authenticating redactions in recent room versions. ([\#5699](#5699), [\#5700](#5700), [\#5707](#5707))
- Ignore redactions of m.room.create events. ([\#5701](#5701))

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

- Base Docker image on a newer Alpine Linux version (3.8 -> 3.10). ([\#5619](#5619))
- Add missing space in default logging file format generated by the Docker image. ([\#5620](#5620))

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

- Add information about nginx normalisation to reverse_proxy.rst. Contributed by @skalarproduktraum - thanks! ([\#5397](#5397))
- --no-pep517 should be --no-use-pep517 in the documentation to setup the development environment. ([\#5651](#5651))
- Improvements to Postgres setup instructions. Contributed by @Lrizika - thanks! ([\#5661](#5661))
- Minor tweaks to postgres documentation. ([\#5675](#5675))

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

- Remove support for the `invite_3pid_guest` configuration setting. ([\#5625](#5625))

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

- Move logging code out of `synapse.util` and into `synapse.logging`. ([\#5606](#5606), [\#5617](#5617))
- Add a blacklist file to the repo to blacklist certain sytests from failing CI. ([\#5611](#5611))
- Make runtime errors surrounding password reset emails much clearer. ([\#5616](#5616))
- Remove dead code for persiting outgoing federation transactions. ([\#5622](#5622))
- Add `lint.sh` to the scripts-dev folder which will run all linting steps required by CI. ([\#5627](#5627))
- Move RegistrationHandler.get_or_create_user to test code. ([\#5628](#5628))
- Add some more common python virtual-environment paths to the black exclusion list. ([\#5630](#5630))
- Some counter metrics exposed over Prometheus have been renamed, with the old names preserved for backwards compatibility and deprecated. See `docs/metrics-howto.rst` for details. ([\#5636](#5636))
- Unblacklist some user_directory sytests. ([\#5637](#5637))
- Factor out some redundant code in the login implementation. ([\#5639](#5639))
- Update ModuleApi to avoid register(generate_token=True). ([\#5640](#5640))
- Remove access-token support from `RegistrationHandler.register`, and rename it. ([\#5641](#5641))
- Remove access-token support from `RegistrationStore.register`, and rename it. ([\#5642](#5642))
- Improve logging for auto-join when a new user is created. ([\#5643](#5643))
- Remove unused and unnecessary check for FederationDeniedError in _exception_to_failure. ([\#5645](#5645))
- Fix a small typo in a code comment. ([\#5655](#5655))
- Clean up exception handling around client access tokens. ([\#5656](#5656))
- Add a mechanism for per-test homeserver configuration in the unit tests. ([\#5657](#5657))
- Inline issue_access_token. ([\#5659](#5659))
- Update the sytest BuildKite configuration to checkout Synapse in `/src`. ([\#5664](#5664))
- Add a `docker` type to the towncrier configuration. ([\#5673](#5673))
- Convert `synapse.federation.transport.server` to `async`. Might improve some stack traces. ([\#5689](#5689))
- Documentation for opentracing. ([\#5703](#5703))