How to Work with GitHub and Multiple Accounts

github_multiple-accounts.md

Step 1 - Create a New SSH Key

We need to generate a unique SSH key for our second GitHub account.

ssh-keygen -t rsa -C "your-email-address"

Be careful that you don't over-write your existing key for your personal account. Instead, when prompted, save the file as id_rsa_COMPANY. In my case, I've saved the file to ~/.ssh/id_rsa_work.

Step 2 - Attach the New Key

Next, login to your second GitHub account, browse to "Account Overview" and attach the new key, within the "SSH Public Keys" section. To retrieve the value of the key that you just created, return to the Terminal and type: vim ~/.ssh/id_rsa_COMPANY.pub.

Copy the entire string that is displayed, and paste this into the GitHub textarea. Feel free to give it any title you wish.

Next, because we saved our key with a unique name, we need to tell SSH about it. Within the Terminal, type: ssh-add ~/.ssh/id_rsa_COMPANY. If successful, you'll see a response of Identity Added.

Step 3 - Create a Config File

We've done the bulk of the workload; but now we need a way to specify when we wish to push to our personal account, and when we should instead push to our company account. To do so, let's create a config file.

touch ~/.ssh/config vim config

If you're not comfortable with Vim, feel free to open it within any editor of your choice. Paste in the following snippet.

Default GitHub

---

	Host github.com
	  HostName github.com
	  User git
	  IdentityFile ~/.ssh/id_rsa

This is the default setup for pushing to our personal GitHub account. Notice that we're able to attach an identity file to the host. Let's add another one for the company account. Directly below the code above, add:

	Host github-COMPANY
	  HostName github.com
	  User git
	  IdentityFile ~/.ssh/id_rsa_COMPANY

This time, rather than setting the host to github.com, we've named it as github-COMPANY. The difference is that we're now attaching the new identity file that we created previously: id_rsa_COMPANY. Save the page and exit!

Step 4 - Try it Out

It's time to see if our efforts were successful. Create a test directory, initialize git, and create your first commit.

	git init
	git commit -am "first commit'

Login to your company account, create a new repository, give it a name of "Test," and then return to the Terminal and push your git repo to GitHub.

	git remote add origin git@github-COMPANY:Company/testing.git
	git push origin master

Note that, this time, rather than pushing to git@github.com, we're using the custom host that we create in the config file: git@github-COMPANY.

Return to GitHub, and you should now see your repository. Remember:

When pushing to your personal account, proceed as you always have. For your company account, make sure that you use git!github-COMPANY as the host.

I had to remove Hostname github.com from the primary account in .ssh/config to get it working

Thanks JoaquimLey for the hints!

One remark on this setup:

It may happen that you have another user and email configured globally.
So even when you connect via ssh to a different GitHub account you are still committing with the other user.
Check your global configuration:

git config --global --list

You can set a different local user an email per repository.
Run this in your repo to set the user for the current repository only:

git config --local user.name "homeuser"
git config --local user.email "homeuser@example.com"