GitHub org membership check does not handle paginated response

[boonware]

Issue Summary:

GitHub org membership check does not support paginated responses from GitHub API.

Environment:

Spinnaker 1.29.0

Feature Area:

GitHub OAuth

Description:

Spin Gate supports a GitHub organization membership check: if the authenticated user is not a member of the target GitHub organization then access is denied. The API call to GItHub that checks user organization memberships does not handle a paginated response from GitHub. If the user is a member of more than the default page size number of orgs (30) then GitHub paginates the response, attaching a Link header with the URL to the next page. Currently, the membership check fails if the user is a member of more than 30 orgs and the target org is not contained in the first page.

Steps to Reproduce:

1. Enable the org membership check.
2. Ensure that the user is a member of more than 30 orgs.
3. Ensure that the target org is not returned in the first page of orgs returned by the GitHub org membership API.
4. Authenticate with Spinnaker via GitHub OAuth.
5. Access is denied.

[spinnakerbot]

This issue hasn't been updated in 45 days, so we are tagging it as 'stale'. If you want to remove this label, comment:

@spinnakerbot remove-label stale

[spinnakerbot]

This issue is tagged as 'stale' and hasn't been updated in 45 days, so we are tagging it as 'to-be-closed'. It will be closed in 45 days unless updates are made. If you want to remove this label, comment:

@spinnakerbot remove-label to-be-closed

[spinnakerbot]

This issue is tagged as 'to-be-closed' and hasn't been updated in 45 days, so we are closing it. You can always reopen this issue if needed.