Using Git submodules with GitLab CI
- GitLab 8.12 introduced a new CI build permissions model and you are encouraged to upgrade your GitLab instance if you haven't done already. If you are not using GitLab 8.12 or higher, you would need to work your way around submodules in order to access the sources of e.g.,
gitlab.com/group/projectwith the use of SSH keys.
- With GitLab 8.12 onward, your permissions are used to evaluate what a CI build can access. More information about how this system works can be found in the Build permissions model.
- The HTTP(S) Git protocol must be enabled in your GitLab instance.
If dealing with Git submodules, your project will probably have a file
Let's consider the following example:
- Your project is located at
- To checkout your sources you usually use an SSH address like
- Your project depends on
https://gitlab.com/group/project, which you want to include as a submodule.
If you are using GitLab 8.12+ and your submodule is on the same GitLab server,
you must update your
.gitmodules file to use relative URLs.
Since Git allows the usage of relative URLs for your
this easily allows you to use HTTP(S) for cloning all your CI builds and SSH
for all your local checkouts. The
.gitmodules would look like:
[submodule "project"] path = project url = ../../group/project.git
The above configuration will instruct Git to automatically deduce the URL that should be used when cloning sources. Whether you use HTTP(S) or SSH, Git will use that same channel and it will allow to make all your CI builds use HTTP(S) (because GitLab CI only uses HTTP(S) for cloning your sources), and all your local clones will continue using SSH.
For all other submodules not located on the same GitLab server, use the full HTTP(S) protocol URL:
[submodule "project-x"] path = project-x url = https://gitserver.com/group/project-x.git
.gitmodules is correctly configured, you can move on to
Using Git submodules in your CI jobs
There are a few steps you need to take in order to make submodules work correctly with your CI builds:
- First, make sure you have used relative URLs for the submodules located in the same GitLab server.
git submodule sync/updatein
before_script: - git submodule sync --recursive - git submodule update --init --recursive
--recursiveshould be used in either both or none (
sync/update) depending on whether you have recursive submodules.
The rationale to set the
before_script is because of
the way Git submodules work. On a fresh Runner workspace, Git will set the
submodule URL including the token in
.git/modules/<submodule>/config) based on
.gitmodules and the current
remote URL. On subsequent builds on the same Runner,
.git/config is cached
and already contains a full URL for the submodule, corresponding to the previous
build, and to a token from a previous build.
sync allows to force updating
the full URL.