Managing Multiple SSH Keys for Multiple Git Accounts in Linux

When working with multiple Git accounts, you need to set up separate SSH keys and configure them properly. This guide will walk you through the process.

Generate SSH Keys for Each Account

Run the following commands to generate unique SSH keys for each Git account:

ssh-keygen -t ed25519 -C "user1@example.com" -f ~/.ssh/id_ed25519_user1_github

ssh-keygen -t ed25519 -C "user2@example.com" -f ~/.ssh/id_ed25519_user2_github

ssh-keygen -t ed25519 -C "user3@example.com" -f ~/.ssh/id_ed25519_user3_bitbucket

Replace the email (user1@example.com, user2@example.com, etc.) with the email address associated with each account.
-f specifies the file name for the key pair.

Add Public Keys to Git Hosting Platforms

For each generated key, add the corresponding public key (~/.ssh/id_ed25519_userX_github.pub) to the SSH settings in your respective Git hosting platform (e.g., GitHub or Bitbucket).

Configure SSH for Multiple Accounts

To link the private keys to their respective accounts, create or update the SSH config file in the ~/.ssh directory:

touch ~/.ssh/config

Add the following configuration to the file:

# Configuration for user1's GitHub account

Host github.com

HostName github.com

User git

IdentityFile ~/.ssh/id_ed25519_user1_github

# Configuration for user2's GitHub account

Host github-secondary

HostName github.com

User git

IdentityFile ~/.ssh/id_ed25519_user2_github

# Configuration for user3's Bitbucket account

Host bitbucket.org

HostName bitbucket.org

User git

IdentityFile ~/.ssh/id_ed25519_user3_bitbucket

Host: Alias to identify the account (e.g., github-secondary).
HostName: The actual hostname of the Git service.
IdentityFile: Path to the private key for the account.

Test the SSH Connection

Test your SSH configuration to ensure everything works correctly:

For the default GitHub account:

ssh -T git@github.com

For the secondary GitHub account:

ssh -T git@github-secondary

For the Bitbucket account:

ssh -T git@bitbucket.org

If successful, you’ll see a message confirming the connection.

Clone Repositories Using Specific Accounts

When cloning repositories(For example https://github.com/username/repository.git), use the corresponding Host alias defined in the SSH config file. For example:

Cloning using the default GitHub account:

git clone git@github.com:username/repository.git

Cloning using the secondary GitHub account:

git clone git@github-secondary:username/repository.git

Cloning using the Bitbucket account:

git clone git@bitbucket.org:username/repository.git

Final Notes

Ensure the SSH agent is running (eval $(ssh-agent -s)) and keys are added using ssh-add if needed.
Double-check file permissions for private keys (chmod 600 ~/.ssh/id_ed25519_*) to avoid issues.

in Linux