[-] fix Invalid command SET lock_timeout... error, fixes #507

[IlyaTsoi]

Fixed error "invalid command 'SET lock_timeout TO '100ms'" when connecting to pgbouncer DB type. #507.
It is possible to add pgbouncer tables with the same structure as "show stats" to collect metrics from them. I was add 'show pools' table in tis commit

[pashagolub]

Hey, thanks a lot for your help.

It is usually a good idea to provide with pull requests only atomic changes. It's better here to have two separate PRs: one for bug fixing and one with a new functionality. For example, I'm not sure if we need pgbouncer_pool table but I'm strongly confident we want a bug fix.

Another advice is to use self descriptive commit messages. There is no need in Update pgwatch2.go string. We will see that from the commit itself.

It's a good idea to create a new branch in your forked repo and then creating pull request from it and not from master. Doing so you may allow authors of the target repo make changes. If you want to allow anyone with push access to the upstream repository to make changes to your pull request, select Allow edits from maintainers.

[IlyaTsoi]

@pashagolub Thanks for the advice, I'll keep that in mind next time. I'm new to this ).

[pashagolub]

No problem. Good job! I'll merge it as it is since there are no huge changes anyway

[vitabaks]

Test

result: not passed

root@7cfb7d2bff54:~# /usr/bin/pgwatch2-daemon --version
cd2790d0f446946bb7bce5f3e063be1928c0d130 (2022-11-23T16:16:29+01:00)

Error:

2022/11/24 09:52:57 WARN main: Could not find PG version info for DB drm-pgnode01_pgbouncer_postgres, skipping shutdown check of metric worker process for pgbouncer_stats
...
2022/11/24 10:03:57 ERRO MetricGathererLoop: Total failed fetches for [drm-pgnode01_pgbouncer_postgres:pgbouncer_stats]: 12
2022/11/24 10:03:57 ERRO MetricGathererLoop: Failed to fetch metric data for [drm-pgnode01_pgbouncer_oms:pgbouncer_stats]: pq: invalid command '
', use SHOW HELP;

[vitabaks]

@IlyaTsoi I'm sorry, but have you tested the collection of metrics with pgbouncer? It didn't work for me (see above).

[IlyaTsoi]

@vitabaks of course! This works well for me. Maybe there is something wrong with the settings? More information required. This issue is discussed here https://github.com/cybertec-postgresql/pgwatch2/issues/550