Impossible mirroring to AWS CodeCommit Using Only SSH Keys

We are interested in mirroring code from Gitlab.com to AWS CodeCommit (push).

This is unfortunately impossible, because:

• AWS CodeCommit doesn't support HTTPS if there isn't a AWS IAM user configured
• SSH doesn't work: AWS requires you to specify a different user, that is the ID of the SSH key you upload to AWS. There is no way I see in Gitlab to specify the user.

Note by @DarwinJS: This issue is specific to the requirement to use SSH Keys, but it should also be known that push mirroring to codecommit does work with user name and password as I updated in the documentation here: Set up a push mirror from GitLab to AWS CodeCommit