Fix always recompile regex URL for rules

[lehainam-dev]

Related issue

This condition always return true, because Rule.Match.compiledURL and Rule.Match.compiledURLChecksum is never updated in RepositoryMemory.rules, leading the expensive function CompileRegex always call each time oathkeeper check an URL is match rules or not.

I found this issue when testing oathkeeper performance with pprof.

Proposed changes

I change the way RepositoryMemory.rules and Rule.Match should update.

Honestly, I am not familiar with golang much. Please review and suggest if you have are better solutions.

Checklist

• I have read the contributing guidelines
• I have read the security policy
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security vulnerability, I
  confirm that I got green light (please contact
  [email protected]) from the maintainers to push
  the changes.
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation within the code base (if appropriate)
• I have documented my changes in the
  developer guide (if appropriate)

[CLAassistant]

All committers have signed the CLA.

[aeneasr]

Thank you! Would it be possible to add a test so this doesn't break in a future change accidentally?

[aeneasr]

Just checking back in if you'd be open for adding a test

[lehainam-dev]

Hi @aeneasr ,
Sorry, I don't think that I would be available to write some tests.
I will pass this issue to your team. Thanks for your incredible work.