An example of how to easily add Git submodules
There are several ways a developer can add Git submodules to an existing repository. They can clone from GitLab, they can do a Git submodule add from GitHub or they can manually create all their repositories and submodules.
This tutorial will focus on the latter approach, which will include a Git submodule add example that doesn’t require any integration with GitHub and doesn’t need any pre-existing repositories. It’s a simple, bare bones approach to learn how the Git submodule add command works, and it’s the best way to learn how submodules in Git work.
How to add Git submodules
A developer can follow these eight steps to add Git submodules:
- Create a repository with the git init command. This will be the parent module/repository.
- Add files and perform at least one commit to the parent repository before you add Git submodules
- Add a new subfolder in the Git repository
- Perform a git init in the new subfolder
- Add files and perform at least one commit on the repository in the subfolder
- From the root of the parent module, issue a git submodule add command and specify the path to the subfolder
- Perform a git status and verify the parent repository contains a file named .gitmodules
- Add the .gitmodules file to the index and then perform a commit.
The git submodule add command create a .gitmodules file.
If a developer completes these steps and doesn’t receive an error message, they will have successfully performed a git submodule add.
Git submodule add commands
The actual commands used in the example are:
submodule@example:~$ mkdir surface submodule@example:~$ cd surface submodule@example:~$ git init submodule@example:~$ touch destroyer.html submodule@example:~$ git add . submodule@example:~$ git commit -m "Add surfae fleet" submodule@example:~$ mkdir submarines submodule@example:~$ cd submarines submodule@example:~$ git init submodule@example:~$ touch nuclear.html submodule@example:~$ git add . submodule@example:~$ git commit -m "Add submarine to fleet" submodule@example:~$ cd .. submodule@example:~$ git submodule add ./submarines submodule@example:~$ git init submodule@example:~$ git add . submodule@example:~$ git commit -m "Add the submodule submarines"
How to add submodules in GitLab
If a developer uses GitLab as their repository of choice, this video demonstrates how to do a Git submodule add with GitLab.
Further git submodule add examples
I performed this Git submodule add example locally by initializing all the required repositories. To see how to add a submodule through a clone, you might want to view this GitHub submodule example.