How to Use GitHub with Multiple Users?

Using GitHub with multiple users can be essential for collaboration within a team, across multiple projects, or even if you have separate personal and professional GitHub accounts. Working with multiple users requires some configuration to ensure smooth transitions between accounts and to prevent authentication issues.

This post will show you how to set up and manage multiple GitHub accounts effectively on your machine.

Why Use Multiple GitHub Accounts?

Here are a few reasons why managing multiple GitHub accounts may be necessary:

1. Separating Work and Personal Projects: Use different accounts for work-related and personal projects to keep boundaries clear.
2. Collaborating on Multiple Teams: As a freelancer or collaborator on multiple teams, you might need access to different GitHub organizations with separate permissions.
3. Managing Permissions: When contributing to repositories with different permission requirements, having dedicated accounts can be more secure and efficient.

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Prerequisites

Ensure you have:

• Git installed on your system.
• Existing GitHub accounts for the users you plan to configure.

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Step 1: Generate SSH Keys for Each GitHub Account

To keep your accounts separated, start by generating SSH keys for each GitHub account.

1. Open a Terminal (or Git Bash on Windows).

2. Generate an SSH Key Pair for Each Account.

For example, if you have a personal account and a work account, generate separate keys:

# Personal Account
ssh-keygen -t ed25519 -C "[email protected]" -f ~/.ssh/id_ed25519_personal

# Work Account
ssh-keygen -t ed25519 -C "[email protected]" -f ~/.ssh/id_ed25519_work

The -f flag specifies the filename for the SSH key. You’ll create one for each account so that they remain separate.

3. Add SSH Keys to the SSH Agent.

eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519_personal
ssh-add ~/.ssh/id_ed25519_work

4. Add the SSH Keys to Your GitHub Accounts.

• Log in to each GitHub account, navigate to Settings > SSH and GPG keys, and add the corresponding SSH key for each account.

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Step 2: Configure SSH for Multiple GitHub Accounts

To manage multiple accounts, create an SSH configuration file to map each account to a specific GitHub alias.

1. Open or create an SSH configuration file:

   nano ~/.ssh/config

2. Add the following configuration for each account:

   # Personal GitHub Account
   Host github-personal
     HostName github.com
     User git
     IdentityFile ~/.ssh/id_ed25519_personal

   # Work GitHub Account
   Host github-work
     HostName github.com
     User git
     IdentityFile ~/.ssh/id_ed25519_work

With this setup, github-personal and github-work are aliases for GitHub, each pointing to a different SSH key.

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Step 3: Clone Repositories Using the Correct SSH Alias

When cloning a repository, use the specific SSH alias defined in your configuration:

# Clone using personal account
git clone git@github-personal:your-username/your-repo.git

# Clone using work account
git clone git@github-work:your-work-username/work-repo.git

This approach ensures that GitHub will recognize the correct SSH key associated with each account.

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Step 4: Configure Git to Use Different User Information per Repository

If you have different Git user information (name and email) for each account, configure Git to use the correct information for each repository.

1. Navigate to the Repository:

   cd /path/to/your-repo

2. Set the Git Configurations:

   # Set personal user information
   git config user.name "Your Name (Personal)"
   git config user.email "[email protected]"

For work repositories, use:

   # Set work user information
   git config user.name "Your Name (Work)"
   git config user.email "[email protected]"

Git will now use the correct user information for commits in each repository.

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Step 5: Manage Remote URLs for Multiple Accounts

For projects where you need both personal and work contributions, you can add both accounts as remotes.

1. Navigate to the Repository:

   cd /path/to/your-repo

2. Add Remotes:

   # Personal remote
   git remote add personal git@github-personal:your-username/your-repo.git

   # Work remote
   git remote add work git@github-work:your-work-username/work-repo.git

3. Push to a Specific Remote: Specify the remote each time you push to ensure the correct account is used:

   # Push using personal account
   git push personal main

   # Push using work account
   git push work main

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Step 6: Switch Between Accounts for GitHub CLI (Optional)

If you use the GitHub CLI (gh), configure it to switch between accounts using gh auth login.

1. Login with GitHub CLI:

   gh auth login

2. Select the Appropriate GitHub Account: The GitHub CLI will prompt you to log in with the account you need. Repeat this to switch accounts when necessary.

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Tips for Working with Multiple GitHub Accounts

• Use Repository-specific Configurations: Set user information per repository to avoid commit attribution issues.
• Test Configurations: Run ssh -T git@github-personal or ssh -T git@github-work to verify that each SSH key is correctly linked to its GitHub account.
• Document Your Configurations: Keeping notes on SSH configurations, Git remotes, and account aliases will save time in future setups.

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Conclusion

Managing multiple GitHub accounts on the same machine may initially seem complex, but by using SSH keys, custom aliases, and repository-specific configurations, you can streamline the process. This approach ensures that you can seamlessly switch between personal, work, or team accounts, maintaining an organized and efficient workflow.