How To Configure Multiple Git Accounts with SSH on Your Local Machine

Imagine you're working with multiple organizations, each managing code versions differently. For example, you may need to create a new Git account using your work email while you already have Git set up for your personal account. In another scenario, each organization might use a different version control platform, such as GitHub, GitLab, or Bitbucket.

This quick guide will walk you through the steps of managing such a setup, applicable to Windows, Mac OS, and Linux. The ~/.ssh/config files work similarly across Linux, Mac Os and Windows since they are part of the OpenSSH suite. However, a notable difference is that Linux & Mac Os typically come with SSH pre-installed and accessible in the PATH, whereas on Windows, OpenSSH often needs to be installed manually.

Setting Up Multiple Git Accounts Using SSH

We will cover two types of setups you might encounter:

1. Multiple authentication methods on a single version control platform (e.g., GitHub).
2. Different version control platforms, each with its own authentication method.

The following is a graphical representation of the SSH authentication setup we will be implementing.

Step 1: Generate Unique SSH Keys

Naming your keys properly is crucial. I recommend using this naming convention: nameofvcplatform_nameoforganization_rsa. For example, github_tesla_rsa.

# GitHub Personal Acct
ssh-keygen -t rsa -b 4096 -C "your_email@personal.com" -f ~/.ssh/github_personal_rsa

# GitHub Organization Acct
ssh-keygen -t rsa -b 4096 -C "your_email@organization-name.com" -f ~/.ssh/github_organizationname_rsa

# GitLab
ssh-keygen -t rsa -b 4096 -C "your_email@organization-name.com" -f ~/.ssh/gitlab_organizationname_rsa

# Bitbucket
ssh-keygen -t rsa -b 4096 -C "your_email@organization-name.com" -f ~/.ssh/bitbucket_organizationname_rsa

Step 2: Add SSH Keys to SSH Agent

In our case this would be:

eval "$(ssh-agent -s)"
ssh-add ~/.ssh/github_personal_rsa
ssh-add ~/.ssh/github_organizationname_rsa
ssh-add ~/.ssh/gitlab_organizationname_rsa
ssh-add ~/.ssh/bitbucket_organizationname_rsa

Step 3: Add SSH Keys to Each Platform

Copy the public key and add it to your Git account. On Linux, use the cat command to display the key. Alternatively, find the appropriate command for your OS or simply open the key file and copy its contents."

# Copy public key
cat ~/.ssh/github_personal_rsa
cat ~/.ssh/github_organizationname_rsa
cat ~/.ssh/gitlab_organizationname_rsa
cat ~/.ssh/bitbucket_organizationname_rsa

GitHub: Go to [SSH and GPG Keys(https://github.com/settings/keys).
GitLab: Go to SSH Keys.
Bitbucket: Go to SSH Keys.

Step 4. Configure SSH Config File

Create or edit the ~/.ssh/config file to define how SSH should handle each account.

The SSH config file is essential because it defines the hosts, enabling you to distinguish between different version control platforms and accounts by their names. Take a look at the SSH config for our repositories.

Note how Host and IdentityFile are configured.

# GitHub Personal
Host github-personal.com
  HostName github.com
  User git
  IdentityFile ~/.ssh/github_personal_rsa

# GitHub Organization
Host github-organizationname.com
  HostName github.com
  User git
  IdentityFile ~/.ssh/github_organizationname_rsa

# GitLab
Host gitlab-organizationname.com
  HostName gitlab.com
  User git
  IdentityFile ~/.ssh/gitlab_organizationname_rsa

# Bitbucket
Host bitbucket-organizationname.org
  HostName bitbucket.org
  User git
  IdentityFile ~/.ssh/bitbucket_organizationname_rsa

Step 5: Using the repositories

The commands for cloning, pulling, or pushing will change based on the custom host names defined in the SSH config

For example:

1. Cloning Repositories
Instead of using the default host names (e.g., github.com, gitlab.com), you'll use the custom host names defined in the SSH config:

GitHub Personal:

git clone git@github-personal.com:username/repo.git

GitHub Organization:

git clone git@github-organizationname.com:organization/repo.git

**GitLab:**

git clone git@gitlab-organizationname.com:organization/repo.git

Bitbucket:

git clone git@bitbucket-organizationname.org:organization/repo.git

2. Pulling or Pushing Changes

For pulling or pushing changes, you will use the same format, referencing the custom host names:

GitHub Personal:

git pull git@github-personal.com:username/repo.git
git push git@github-personal.com:username/repo.git

GitHub Organization:

git pull git@github-organizationname.com:organization/repo.git
git push git@github-organizationname.com:organization/repo.git

GitLab:

git pull git@gitlab-organizationname.com:organization/repo.git
git push git@gitlab-organizationname.com:organization/repo.git

Bitbucket:

git pull git@bitbucket-organizationname.org:organization/repo.git
git push git@bitbucket-organizationname.org:organization/repo.git

3. Setting Remote URL for Existing Repositories

If you want to update the remote URL for an existing repository, you can use the following command:

GitHub Personal:

git remote set-url origin git@github-personal.com:username/repo.git

GitHub Organization:

git remote set-url origin git@github-organizationname.com:organization/repo.git

GitLab:

git remote set-url origin git@gitlab-organizationname.com:organization/repo.git

Bitbucket:

git remote set-url origin git@bitbucket-organizationname.org:organization/repo.git

These adjustments ensure that Git uses the appropriate SSH key for the specified host, as defined in your SSH config file.

I hope you found the article helpful. Thank you for reading!