Make SSH Environment available after sudo-ing to another User

March 24, 2016

If you have 2FA enabled on Github (which you should have), you have to use the SSH method to do git operations related to your repo. This becomes a pain when you’re doing a lot of remote work (that you haven’t yet automated); because you either have to generate a unique password that you can use during the deploy, or switch off 2FA.

Luckily, GitHub has provided an excellent guide on how to enable SSH Agent Forwarding:

However, at times you need to work as root or a different user from the one you logged in remotely as.

To make sure agent forwarding works even after sudo-_ing_ to another user, you need to keep the SSH_AUTH_SOCK variable available.

On Ubuntu, you do this by adding the following to your /etc/sudoers file:

Defaults        env_keep+=SSH_AUTH_SOCK

Make sure you use visudo to edit the file, so that it’s validated before saving; otherwise you risk losing superpowers on your server 😂

Once you do this, log in & out again, and you should be able to access your Github repos using your key. You can do the test given by Github:

ssh -T [email protected]

You’ll get a response like the one below:

Hi {github username}! You've successfully authenticated, but GitHub does not provide shell access.

Happy Coding!