Add support for /api/v1/format_query API

[siddarth2810]

What this PR does:
The PR enables /api/v1/format_query API endpoint for formatting queries on Query Frontend and Querier

Which issue(s) this PR fixes:
Fixes #6670

Checklist

• [NA] Tests updated
• Documentation added
• CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX]

[SungJin1212]

Thanks for the contribution. Do we have to require the auth?

[siddarth2810]

Thanks for the contribution. Do we have to require the auth?

I ran a simple curl command and it only worked when I added the Auth Header and in documentation I noticed most the API endpoints for query frontend needed authentication so I concluded that, this endpoint too must need authentication.

Let me know if I should be doing some additional checks, would really appreciate it. Thank you so much

[SungJin1212]

This API is for PromQL pretty-formatting, I'm just wondering if the authentication is necessary for it.
@friedrich-at-adobe can you take a look?

[siddarth2810]

This API is for PromQL pretty-formatting, I'm just wondering if the authentication is necessary for it. @friedrich-at-adobe can you take a look?

I see, I went through some documentation and based on Prometheus security what I understand is that a standalone prometheus server dosent need any auth because its presumed that untrusted users have access to the Prometheus HTTP endpoint

but when cortex acts as a prometheus web server it would still look for tenant ID on each request, as mentioned in Cortex Auth, so in the end we need auth ?

Apologies for any confusion I caused

[friedrichg]

@siddarth2810 This looks good, but needs an integration test. Can you add it?

[friedrichg]

Thanks for the contribution. Do we have to require the auth?

I believe auth is handled already. The integration test will prove it.