Recently it has happened two times when people tried to deploy the new cluster but postgres data directory wasn't empty and also wasn't valid. In this case Patroni was still creating initialize key in DCS and trying to start the postgres up.
Now it will complain about non-empty invalid postgres data directory and exit.
Close https://github.com/zalando/patroni/issues/1216
The /history endpoint shows the content of the `history` key in DCS
The /cluster endpoint show all cluster members and some service info like pending and scheduled restarts or switchovers.
In addition to that implement `patronictl history`
Close#586Close#675Close#1133
It is possible that some config files are not controlled by Patroni and when somebody is doing reload via REST API or by sending SIGHUP to Patroni process the usual expectation is that postgres will also be reloaded, but it didn't happen when there were no changes in the postgresql section of Patroni config.
For example one might replace ssl_cert_file and ssl_key_file on the filesystem and starting from PostgreSQL 10 it just requires a reload, but Patroni wasn't doing it.
In addition to that fix the issue with handling of `wal_buffers`. The default value depends on `shared_buffers` and `wal_segment_size` and therefore Patroni was exposing pending_restart when the new value in the config was explicitly set to -1 (default).
Close https://github.com/zalando/patroni/issues/1198
* use `SHOW primary_conninfo` instead of parsing config file on pg12
* strip out standby and recovery parameters from postgresql.auto.conf before starting the postgres 12
Patroni config remains backward compatible.
Despite for example `restore_command` converted to a GUC starting from postgresql 12, in the Patroni configuration you can still keep it in the `postgresql.recovery_conf` section.
If you put it into `postgresql.parameters.restore_command`, that will also work, but it is important not to mix both ways:
```yaml
# is OK
postgresql:
parameters:
restore_command: my_restore_command
archive_cleanup_command: my_archive_cleanup_command
# is OK
postgresql:
recovery_conf:
restore_command: my_restore_command
archive_cleanup_command: my_archive_cleanup_command
# is NOT ok
postgresql:
parameters:
restore_command: my_restore_command
recovery_conf:
archive_cleanup_command: my_archive_cleanup_command
```
* Convert postgresql.py into a package
* Factor out cancellable process into a separate class
* Factor out connection handler into a separate class
* Move postmaster into postgresql package
* Factor out pg_rewind into a separate class
* Factor out bootstrap into a separate class
* Factor out slots handler into a separate class
* Factor out postgresql config handler into a separate class
* Move callback_executor into postgresql package
This is just a careful refactoring, without code changes.
