Support co-authors in GitHub flows with Copilot AI as main author and actual contributor as co-author

[lukaszgryglicki]

We handle co-authors by searching (case insensitive) for co-authored-by: name <email> git commit trailers.

When handling (name, email) pairs we resolve potential GitHub users as follows:

1. Match by ID + Login:

• If the email matches the pattern id+login@users.noreply.github.com, extract the numeric GitHub ID and look up the user by ID.

2. Match by Login:

• If the email matches login@users.noreply.github.com, extract the login and look up the user by GitHub username.

3. Lookup by Email:

• Otherwise, attempt to find the user using the email address via the GitHub API.

4. Fallback to Name as Login:

If all else fails, attempt to look up the user treating the provided name as a possible GitHub login (from Co-authored-by: name <email> - we assume that name is login - this is true for AI bots checked so far).

This sequence ensures the most reliable identification of GitHub co-authors from commit metadata.

Internally we cache GitHub users found (or not found which is the most time consuming operation) with TTL = 24 hours and using (name, email) from co-authored-by trailer as a key.

This is implemented in both python and golang backends.

cc @mlehotskylf @jarias-lfx @ahmedomosanya

[Copilot]

Pull Request Overview

This PR implements co-authors support in GitHub flows, allowing CLA systems to handle commits where Copilot AI is the main author and actual contributors are listed as co-authors. The system parses co-authored-by: commit trailers and attempts to resolve GitHub users through multiple lookup strategies.

Key changes:

• Added database schema and configuration support for enabling co-authors per repository
• Implemented comprehensive GitHub user lookup logic with caching for co-authors
• Enhanced commit processing to include co-author analysis when enabled

Reviewed Changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
utils/skip_cla_entry.sh	Updated example patterns for Copilot-related entries
utils/enable_co_authors_entry.sh	New utility script for managing co-authors configuration
utils/copy_prod_case_4.sh	New script for copying production data for testing
cla-backend/cla/utils.py	Enhanced co-authors extraction with case-insensitive regex
cla-backend/cla/tests/unit/test_github_models.py	Added cache clearing and mock updates for co-authors tests
cla-backend/cla/models/github_models.py	Core implementation of co-authors support with caching and GitHub user lookup
cla-backend/cla/models/dynamo_models.py	Added enable_co_authors field to GitHub organization model
cla-backend-go/v2/sign/helpers.go	Updated Go backend to support co-authors in change requests
cla-backend-go/swagger/common/github-organization.yaml	Added API documentation for enableCoAuthors field
cla-backend-go/signatures/service.go	Updated signature service to use co-authors support
cla-backend-go/github_organizations/models.go	Added EnableCoAuthors field to Go organization model
cla-backend-go/github/github_repository.go	Implemented comprehensive co-authors processing in Go
cla-backend-go/github/bots.go	Added repository pattern matching for co-authors enablement
README.md	Added reference to co-authors documentation
CO_AUTHORS.md	Comprehensive documentation for co-authors feature

[mlehotskylf]

This looks good, my only concerns is that with this approach some co-authors can be identified and some may not, introducing inconsistency. To fix this I suggest:

1. If maintainers will ask us to enable "co-author feature" for the repo/org then ALL co-authors need to be identified AND be authorized, otherwise entire PR will not pass EasyCLA check. This means co-author trailer always need to have expected format with identifiable co-authors.
2. If maintainers don't enable co-author feature (default), then EasyCLA will keep current behavior (ignore co-authors)

[lukaszgryglicki]

@mlehotskylf :
1 - this is exactly the case.
2- this is exactly the case.

[mlehotskylf]

Great, thank you for confirmation. Please add this to the documentation.

[lukaszgryglicki]

Added https://github.com/linuxfoundation/lfx-product-documentation/pull/12.