|November 3rd, 2022|
The natural thing to try would be to add the same public key to your second repo, but GitHub rejects this:
Error: Key is already in use
I think this error is because they don't want you to get into a situation where multiple machines are using the same key. If that happened and you needed to revoke one machine's access, you'd be stuck. In this case, however, we only have one machine and we're trying to use the same key for two repos. I don't see any issues with that setup, and while maybe I'm not being imaginative enough I think GitHub should probably be checking for duplicate deploy keys on a per-repo basis instead of globally?
Still, what can we do with GitHub as it is? Generate more keys and use aliases!
I'm going to walk through this assuming you're starting from scratch
trying to check out both
github.com/you/repo2. If you already have
repo1 working and don't mind having the two repos
configured differently, just follow the
First, generate a ssh key for each repo:
$ ssh-keygen -t ed25519 -C "machineName-repo1" Enter file in which to save the key: /home/you/.ssh/id_ed25519.repo1 ... $ ssh-keygen -t ed25519 -C "machineName-repo2" Enter file in which to save the key: /home/you/.ssh/id_ed25519.repo2 ...
github.com/you/repo1/settings/keys and paste the contents
At this point you've created the keys and told GitHub to respect them,
but you haven't told
ssh on your machine when to use
which key. You do that in
Host github-repo1 HostName github.com User git IdentityFile ~/.ssh/id_ed25519.repo1 IdentitiesOnly yes Host github-repo2 HostName github.com User git IdentityFile ~/.ssh/id_ed25519.repo1 IdentitiesOnly yes
Anyway, now you can check out your repos:
$ git clone github-repo1:you/repo1.git $ git clone github-repo2:you/repo2.git
The reason this works is that
git, like anything else that uses
actually interpret the host name or set up the connection. It just
ssh "please connect me to
ssh will use aliases as part of figuring out how to
do that. This also means that almost any time you might have used
GIT_SSH_COMMAND, or otherwise passed arguments to
ssh, an alias is a better choice.
If you'd already checked out your repo, however, instead of checking
it out again you just change where
$ cd repo1 $ git remote set-url origin github-repo1:you/repo1.git
And the same for