`git clone project2` in gitlab-ci.yml?

I'd like Gitlab CI to fetch source code of another project. Is there a better way than adding a read-only deploy key and setting it up in .gitlab-ci.yml?

Can you Git clone from GitLab?

After you successfully clone the GitLab repository, navigate into the newly created gitlab-made-easy folder. Inside you will see a README file, which verifies that the clone operation was successful.

How do I clone a specific branch?

You can clone a specific branch from a Git repository using the git clone –single-branch –branch command. This command retrieves all the files and metadata associated with one branch. To retrieve other branches, you'll need to fetch them later on.

You can also use GIT SUBMODULES within your project A to refer to project B and then add

GIT_SUBMODULE_STRATEGY: recursive

to the gitlab-ci.yml file in project A.

This also enables you to specifically include a specific branch or commit from your subproject.

https://docs.gitlab.com/ce/ci/git_submodules.html