Specify an SSH key for git push for a given domain

Question

I have the following use case: I would like to be able to push to [email protected]:gitolite-admin using the private key of user gitolite-admin, while I want to push to [email protected]:some_repo using 'my own' private key. AFAIK, I can't solve this using ~/.ssh/config, because the user name and server name are identical in both cases. As I mostly use my own private key, I have that defined in ~/.ssh/config for [email protected]. Does anyone know of a way to override the key that is used for a single git invocation?

(Aside: gitolite distinguishes who is doing the pushing based on the key, so it's not a problem, in terms of access, ownership and auditing, that the user@server string is identical for different users.)

Answer 1

Even if the user and host are the same, they can still be distinguished in ~/.ssh/config. For example, if your configuration looks like this:

Host gitolite-as-alice   HostName git.company.com   User git   IdentityFile /home/whoever/.ssh/id_rsa.alice   IdentitiesOnly yes  Host gitolite-as-bob   HostName git.company.com   User git   IdentityFile /home/whoever/.ssh/id_dsa.bob   IdentitiesOnly yes 

Then you just use gitolite-as-alice and gitolite-as-bob instead of the hostname in your URL:

git remote add alice git@gitolite-as-alice:whatever.git git remote add bob git@gitolite-as-bob:whatever.git 

Note

You want to include the option IdentitiesOnly yes to prevent the use of default ids. Otherwise, if you also have id files matching the default names, they will get tried first because unlike other config options (which abide by "first in wins") the IdentityFile option appends to the list of identities to try. See: https://serverfault.com/questions/450796/how-could-i-stop-ssh-offering-a-wrong-key/450807#450807