SSH key setup with multiple Github account

Setup ssh keys for multiple github account

Many people have more than one Github accout, tipically one for work and the other is for personal projects. Things get more complecated since there are more ssh keys now. While It's better to use docker containers for each development environment, inside each container you can setup ssh like before -- generate id_rsa using all default options, but put all ssh keys in host should work just fine, with a bit more works as this guide shows.

1. generate two ssh keys or copy it from host in case of using container

   ssh-keygen -t rsa -b 4096 -C "your_personal_email@example.com"
   ssh-keygen -t rsa -b 4096 -C "your_work_email@example.com"

   copy ssh key(s) to each github account respectively

2. edit ./ssh/config

   Host github_work
   HostName github.com
   User git
   IdentityFile ~/.ssh/id_rsa_work

   Host github-private-quantum
   HostName github.com
   User git
   IdentityFile ~/.ssh/quantumabacus_rsa

3. test ssh connection

   ssh -T git@github_work
   ssh -T git@github-private-quantum

   This will tell you some account information:

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

4. Cloning repository using a specific ssh key
   For this example I will clone this repository: https://github.com/xyzluo/test_n. You should use your own test repository.

5. Important: remote url should use git as user name and Host defined in ~.ssh/config.

   git clone git@github-private-quantum:xyzluo/test_n.git

6. Once it's done, run git remote -v you'll see this:

   origin  git@github-private-quantum:xyzluo/test_n.git (fetch)
   origin  git@github-private-quantum:xyzluo/test_n.git (push)