This post is just a note to my future self on how to add multiple push URLs to a single git remote.
Adding The URLs
First, add a new remote to your git repository.
git remote add all git@server1:repo.git
Then, redefine the push URL of the remote.
git remote set-url --add --push all git@server1:repo.git
Finally, add the URL of your second remote.
git remote set-url --add --push all git@server2:repo.git
Confirming The Changes
At the end, confirm that all URLs were set correctly.
git remote -v
The output should now be similar to this:
all git@server1:repo.git (fetch)
all git@server1:repo.git (push)
all git@server2:repo.git (push)