How to Manage Multiple SSH Keys for GitHub, GitLab, etc.

Short tutorial on how to structure projects and setup multi-user Git SSH workflow.

When using a single machine with multiple git accounts, you might encounter some obstacles with SSH setup. The easiest way to achieve a multi-user setup is to structure git repositories by respective directories, e.g.:

projects
├── work
│   ├── enterprise-fiz-buz
│   └── ...
└── personal
    ├── karolis.sh
    └── ...

This short tutorial will help you set up SHH for such workflow.

Generating a new SSH key

To generate a new SSH key, use the provided template script (or check the docs):

export EMAIL=karolis.sarapnickis@work.com
export SSH_FILE=$HOME/.ssh/id_rsa_work
ssh-keygen -t rsa -b 4096 -C $EMAIL -f $SSH_FILE
ssh-add -K $SSH_FILE
echo "🔽 PUBLIC KEY BELOW 🔽" && cat $SSH_FILE.pub
pbcopy < $SSH_FILE.pub

What's left is to add the SSH key to your GitHub/GitLab/etc. account.

Multi-user Git SSH setup

The general idea is that you use specific ssh command based on your working directory with the help of git includes.

Update the ~/.gitconfig file:

[user]
  name = Karolis Šarapnickis
  email = pastas.k@gmail.com
[core]
  sshCommand = ssh -i ~/.ssh/id_rsa
[push]
  default = current
[includeIf "gitdir:~/projects/work/"]
  path = ~/.gitconfig.work

And the ~/.gitconfig.work file:

[user]
  email = karolis.sarapnickis@work.com
[core]
  sshCommand = ssh -i ~/.ssh/id_rsa_work

And that's it! Appropriate SSH setup will be used based on directory location, no extra actions are needed.