This PR does the following:
- adds a `keysize` parameter to `generate-keys`, so we can use lower sized keys when running in CI
- updates the Complement docker files to use BuildKit (requires Docker >18.09)
- uses `exec` when executing `dendrite-monotlith-server`, making it PID 1 inside docker, which results in Dendrite actually receiving the `SIGTERM` signal send by Docker. (Making it faster when running tests with Complement, as we don't take 10 seconds to timeout)
* Fix flakey sytest 'Local device key changes get to remote servers'
* Debug logs
* Remove internal/test and use /test only
Remove a lot of ancient code too.
* Use FederationRoomserverAPI in more places
* Use more interfaces in federationapi; begin adding regression test
* Linting
* Add regression test
* Unbreak tests
* ALL THE LOGS
* Fix a race condition which could cause events to not be sent to servers
If a new room event which rewrites state arrives, we remove all joined hosts
then re-calculate them. This wasn't done in a transaction so for a brief period
we would have no joined hosts. During this interim, key change events which arrive
would not be sent to destination servers. This would sporadically fail on sytest.
* Unbreak new tests
* Linting
