git submodule add private repo in private repo

Question

People ask and ask how git submodule add in case where both repos are private?

Answer 1

This is my example.

Let's generate key pairs for every private repo.

user@linux:~/.ssh$ cd $HOME/.ssh && ssh-keygen -t ed25519 -f "myMother_key" -N "" -C "myKeyForGitHubMother" <<< $'\ny' >/dev/null 2>&1
user@linux:~/.ssh$ cd $HOME/.ssh && ssh-keygen -t ed25519 -f "myBaby_key" -N "" -C "myKeyForGitHubBaby" <<< $'\ny' >/dev/null 2>&1

Via FireFox I open github.com and manually add myMother_key.pub file to [email protected]:AndreiCherniaev/mother.git repo (Allow write access checkbox yes) and myBaby_key.pub to [email protected]:AndreiCherniaev/baby.git (Allow write access checkbox yes)

I am Using multiple repositories on one server So my ~/.ssh/config file contains

Host babysubdomain.github.com
  HostName github.com
  User git
  IdentityFile ~/.ssh/myBaby_key
  IdentitiesOnly yes

Host mothersubdomain.github.com
  HostName github.com
  User git
  IdentityFile ~/.ssh/myMother_key
  IdentitiesOnly yes

Where babysubdomain. mothersubdomain. is any text.

Let's clone baby repo.

user@linux:~$ git clone [email protected]:AndreiCherniaev/baby.git

Just for fun let's add any public repo as submodule for baby. In my example I will use Buildroot project

user@linux:~$ cd baby
user@linux:~/baby$ git submodule add -b master https://github.com/buildroot/buildroot myBuildroot/buildroot
user@linux:~/baby$ git commit -m "add submodule myBuildroot/buildroot/ to baby"
user@linux:~/baby$ git push

Let's back to Download/ and clone mother repo

user@linux:~/baby$ cd ..
user@linux:~$ git clone [email protected]:AndreiCherniaev/mother.git
user@linux:~$ cd mother

Let's add submodule to mother repo

user@linux:~$ cd mother/
user@linux:~/mother$ git submodule add -b main [email protected]:AndreiCherniaev/baby.git
user@linux:~/mother$ git commit -m "add submodule baby to mother"
user@linux:~/mother$ git push

Now let's remove local copy of mother/ from your PC

user@linux:~/mother$ cd ..
user@linux:~$ rm -Rf mother/

Let's clone mother with baby with buildroot

git clone --recurse-submodules -j8 [email protected]:AndreiCherniaev/mother.git

Now we have repo mother with submodule baby with submodule myBuildroot/buildroot/

Thanks Gubatron and link. Tested on Ubuntu 22.