ENG-725 Add settings for read-only Redis and for test Redis index

[erosselli]

Closes ENG-725

Description Of Changes

Adds settings to be able to configure a read-only Redis instance, and a method to get this instance.

This also adds a test_db_index to be used when test mode is on.

Steps to Confirm

1. Tests pass; code will be used in my Fidesplus PR

Pre-Merge Checklist

• Issue requirements met
• All CI pipelines succeeded
• CHANGELOG.md updated
  • Add a db-migration This indicates that a change includes a database migration label to the entry if your change includes a DB migration
  • Add a high-risk This issue suggests changes that have a high-probability of breaking existing code label to the entry if your change includes a high-risk change (i.e. potential for performance impact or unexpected regression) that should be flagged
  • Updates unreleased work already in Changelog, no new entry necessary
• Followup issues:
  • Followup issues created
  • No followup issues
• Database migrations:
  • Ensure that your downrev is up to date with the latest revision on main
  • Ensure that your downgrade() migration is correct and works
    • If a downgrade migration is not possible for this change, please call this out in the PR description!
  • No migrations
• Documentation:
  • Documentation complete, PR opened in fidesdocs
  • Documentation issue created in fidesdocs
  • If there are any new client scopes created as part of the pull request, remember to update public-facing documentation that references our scope registry
  • No documentation updates required

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

2 Skipped Deployments

Name	Status	Preview	Comments	Updated (UTC)
fides-plus-nightly	⬜️ Ignored (Inspect)	Visit Preview		Jun 11, 2025 8:29pm
fides-privacy-center	⬜️ Ignored (Inspect)			Jun 11, 2025 8:29pm

[galvana]

Looks good! Aside from the embedded test code in _determine_redis_db_index which we already flagged for a follow up. Good test coverage here ✅

[codecov]

Codecov Report

Attention: Patch coverage is 97.67442% with 1 line in your changes missing coverage. Please review.

Project coverage is 87.14%. Comparing base (ab8d9e4) to head (926d235).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/fides/api/util/cache.py	94.73%	0 Missing and 1 partial ⚠️

❌ Your patch status has failed because the patch coverage (97.67%) is below the target coverage (100.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6217      +/-   ##
==========================================
+ Coverage   87.13%   87.14%   +0.01%     
==========================================
  Files         433      433              
  Lines       26828    26863      +35     
  Branches     2932     2935       +3     
==========================================
+ Hits        23376    23411      +35     
  Misses       2820     2820              
  Partials      632      632              

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[cypress]

fides    Run #12979

Run Properties:   Passed #12979  •  88925fd971: ENG-725 Add settings for read-only Redis and for test Redis index (#6217)

Project	fides
Branch Review	main
Run status	Passed #12979
Run duration	00m 51s
Commit	88925fd971: ENG-725 Add settings for read-only Redis and for test Redis index (#6217)
Committer	erosselli
View all properties for this run ↗︎

---

Test results
Failures	0
Flaky	0
Pending	0
Skipped	0
Passing	5
View all changes introduced in this branch ↗︎