maint(pam/integration-tests): Run all the tests with a shared authd in race mode

[3v1n0]

Run by default all the tests using an unique instance of authd daemon running so that we can test better that all the codepaths work well with lots of concurrency.

Leaving this as a draft for now because it has dependencies on some commits of #583

UDENG-5377

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 85.18519% with 4 lines in your changes missing coverage. Please review.

Project coverage is 83.14%. Comparing base (36511cd) to head (b9ae2a1).
Report is 336 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/brokers/manager.go	33.33%	3 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #593      +/-   ##
==========================================
- Coverage   83.43%   83.14%   -0.30%     
==========================================
  Files          83       96      +13     
  Lines        8689     9646     +957     
  Branches       74       74              
==========================================
+ Hits         7250     8020     +770     
- Misses       1111     1246     +135     
- Partials      328      380      +52     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[denisonbarbosa]

I'm not going to lie, I'm a bit worried... I like the idea of using a single instance as much as possible, but it will be handling an insane amount of requests (which is not a real use case [how many users do we expect to authenticate in the "same" moment?]).

This feels like it would be a pain to debug and fix if it starts going wrong, no? I'm just wondering if we might not be shooting ourselves in the foot here...

@adombeck, @didrocks any opinions regarding the above?

Despite the rambling: changes look good to me but a comment about naming, easy to fix.

[3v1n0]

Indeed it's not meant to respect a real scenario, but experience taught me that the more we stress a system, the more potential issues can arise.

So, in case we can also make this opt-in and just happen in the race job though.

[didrocks]

I agree that as we don’t have a context ID, this could make things difficult.

How hard would it be to only run in this mode if we are in race mode?

[3v1n0]

I agree that as we don’t have a context ID, this could make things difficult.

How hard would it be to only run in this mode if we are in race mode?

Not much, it's just about inverting the logic, so it should be doable.

[3v1n0]

Blocked by #661 for now, let's wait to reconsider

[3v1n0]

How hard would it be to only run in this mode if we are in race mode?

This is now handled via efe85f9

[adombeck]

I rebased on main again. I skipped ed3bc22 (from this branch) during the rebase which had conflicts with 6c1bf10 (from main). @3v1n0 please take a look if that was the correct decision.

[adombeck]

Looking great, thanks!