via http://www.freshblurbs.com/blog/2013/06/22/github-multiple-ssh-keys.html#tldr Since Github doesn't allow us to reuse an SSH Key, the only sane solution is to jump through some hoops and generate + use multiple keys on the server itself. Let's look at some effective approaches of doing that. Short version: define multiple hosts in the SSH config file for each repository, which use different SSH keys, then you can assign different deploy keys to each repo.

Here's a cfengine bundle that I wrote for editing the sshd configuration file by passing an array with the parameters. Using an array is a very elegant way of defining the values to set. The bundle also restarts sshd after any changes are made, unless the no_restarts class is defined. The first gist contains the edit_sshd bundle itself, together with the set_config_values bundle that actually performs the editing job (this should go into a library file, I have it in my personal version of cfengine_stdlib.