Set up SSH Keys

Let’s assume your two Github accounts are named githubPersonal and githubWork, respectively. Create two SSH keys, saving each to a separate file:

$ cd ~/.ssh
$ ssh-keygen -t rsa -C "your_email@associated_with_githubPersonal.com"
# save it as id_rsa_personal when prompted
$ ssh-keygen -t rsa -C "your_email@associated_with_githubWork.com"
# save it as id_rsa_work when prompted

The above commands setup the following files:

• id_rsa_personal
• id_rsa_personal.pub
• id_rsa_work
• id_rsa_work.pub

Add the keys to your Github accounts:

Copy the key to your clipboard:

$ pbcopy < ~/.ssh/id_rsa_personal.pub

Add the key to your account:

• Go to your Account Settings
• Click “SSH Keys” then “Add SSH key”
• Paste your key into the “Key” field and add a relevant title
• Click “Add key” then enter your Github password to confirm

Repeat the process for your githubWork account.

Create a configuration file to manage the separate keys

Create a config file in ~/.ssh/

$ touch config

Edit the file using the text editor of your choice. I used vim - $ vim config:

# githubPersonal
Host personal
   HostName github.com
   User git
   IdentityFile ~/.ssh/id_rsa_personal

# githubWork
Host work
   HostName github.com
   User git
   IdentityFile ~/.ssh/id_rsa_work

Update stored identities

Clear currently stored identities:

$ ssh-add -D

Add new keys:

$ ssh-add id_rsa_personal
$ ssh-add id_rsa_work

Test to make sure new keys are stored:

$ ssh-add -l

Test to make sure Github recognizes the keys:

$ ssh -T personal
Hi githubPersonal! You've successfully authenticated, but GitHub does not provide shell access.
$ ssh -T work
Hi githubWork! You've successfully authenticated, but GitHub does not provide shell access.

Test PUSH

On Github, create a new repo in your personal account, githubPersonal, called test-personal.

Back on your local machine, create a test directory:

$ cd ~/documents
$ mkdir test-personal
$ cd test-personal

Add a blank “readme.md” file and PUSH to Github:

$ touch readme.md
$ git init
$ git add .
$ git commit -am "first commit"
$ git remote add origin git@personal:githubPersonal/test-personal.git
$ git push origin master

note: Notice how we’re using the custom account, git@personal, instead of git@github.com.

Repeat the process for your githubWork account.

Test PULL

Add some text to the readme.md file in your personal account on Github. Now PULL and merge the changes by running the following command within the test-personal directory:

$ git pull origin master

Again, repeat this for your githubWork account.

Source: https://mherman.org/