Use multiple deployment SSH keys with GitHub

GitHub lets you attach a deploy key to one repository only. The problem is when you want to access multiple repositories with tools like capistrano or, as is our case, webistrano which executes git ls-remote locally before ssh'ing to a remote server and doing git clone there.

Here's the trick to make the tool always use the correct key.

Alias github.com host in your ~/.ssh/config and assign a identity key to it.

Host aliased-github
  HostName github.com
  IdentityFile ~/.ssh/my_deploy_key

Now the tool should be configured to deploy from git@aliased-github:username/repository.git