How to Add SSH Keys to GitLab?

Using SSH keys to authenticate your GitLab projects is a secure and convenient way to manage access without needing to enter your password every time. SSH (Secure Shell) keys provide an encrypted method to communicate with your GitLab repositories, enabling you to push and pull code seamlessly and securely. In this guide, we’ll walk you through creating an SSH key and adding it to your GitLab account.

Why Use SSH Keys in GitLab?

SSH keys offer several benefits:

• Secure Authentication: SSH keys are more secure than password-based authentication as they use cryptographic key pairs.
• Convenience: You don’t need to enter your username and password every time you access the repository.
• Enhanced Control: SSH keys can be configured per user or device, allowing for more granular control over who accesses the repository.

By setting up SSH keys, you’ll have a seamless way to interact with GitLab, enabling faster and safer workflows.

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Step 1: Check for an Existing SSH Key Pair

First, you’ll want to check if an SSH key pair already exists on your system. If you already have an SSH key, you can skip the creation step.

1. Open a Terminal:

• On Windows, you can use Git Bash.
• On macOS and Linux, you can use your default terminal.

1. Check for an Existing Key:

• Run the following command to see if an SSH key already exists:
  bash ls -al ~/.ssh
• Look for files like id_rsa or id_ecdsa, which are the most common names for SSH key pairs. If you see these files, you already have an SSH key.

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Step 2: Generate a New SSH Key Pair (If Necessary)

If you don’t have an existing key, follow these steps to create one:

1. Generate the Key Pair:

• Run the following command to create a new SSH key pair. Replace [email protected] with the email address associated with your GitLab account:
  bash ssh-keygen -t rsa -b 4096 -C "[email protected]"
• This command generates a new SSH key using RSA with a 4096-bit encryption.

1. Save the Key Pair:

• When prompted to specify a file to save the key, press Enter to save it in the default location (~/.ssh/id_rsa).
• Next, you’ll be prompted to enter a passphrase. This step is optional but recommended for added security.

1. Complete the Generation Process:

• After entering a passphrase, the key will be generated, and you’ll see confirmation messages indicating the key’s location.

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Step 3: Add the SSH Key to Your SSH Agent

To manage your SSH key, you’ll need to add it to the SSH agent. This makes it easier to authenticate with GitLab.

1. Start the SSH Agent:

• Run the following command to start the SSH agent in the background:
  bash eval "$(ssh-agent -s)"

1. Add Your SSH Key:

• Use this command to add your SSH private key to the agent:
  bash ssh-add ~/.ssh/id_rsa

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Step 4: Copy the SSH Public Key

To connect your SSH key with GitLab, you need to copy the public key (id_rsa.pub) to add it to your GitLab account.

1. Copy the Public Key:

• Run the following command to copy the contents of your public key to your clipboard:
  bash cat ~/.ssh/id_rsa.pub
• Copy the entire output (it begins with ssh-rsa), ensuring there are no spaces or line breaks.

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Step 5: Add the SSH Key to GitLab

Now that you have your SSH key, you can add it to your GitLab account.

1. Log into GitLab:

• Go to gitlab.com and log in to your account.

1. Navigate to SSH Keys Settings:

• In the upper-right corner, click on your profile icon and go to Settings.
• In the left-hand sidebar, click SSH Keys.

1. Add the SSH Key:

• Paste your SSH public key into the Key field.
• Optionally, you can set an expiration date for the key. This is useful for temporary access.
• Add a descriptive Title to identify the key (e.g., “Work Laptop Key”).
• Click Add Key to save it.

Once added, your SSH key will be listed on your GitLab SSH Keys page, ready for use.

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Step 6: Test Your SSH Connection to GitLab

To ensure that your SSH key has been successfully added, you can test the connection to GitLab:

1. Run the Test Command:

• Open your terminal and enter the following command:
  bash ssh -T [email protected]
• If this is your first time connecting, you’ll be prompted to confirm the connection. Type yes and press Enter.

1. Confirm Success:

• If everything is configured correctly, you should see a message like:
  Welcome to GitLab, @username!
• This message indicates that GitLab recognizes your SSH key and you’re successfully authenticated.

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Troubleshooting Common Issues

1. SSH Key Not Recognized:

• Ensure the key was copied correctly, with no extra spaces or line breaks. Double-check the key path in ssh-add ~/.ssh/id_rsa if you saved it under a different name.

1. Permission Denied Errors:

• Verify the key is loaded in your SSH agent by running ssh-add -l. If it’s not listed, add it again.

1. Expired Key or Invalid Key Format:

• Check your SSH key’s expiration date in GitLab (if set). Also, ensure that the key format is compatible (e.g., ssh-rsa for GitLab).

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Conclusion

Adding an SSH key to GitLab is a straightforward process that significantly improves security and convenience. By following these steps, you’ll have secure access to your GitLab repositories without needing to enter your credentials each time. This setup is ideal for developers who want a seamless, secure authentication process, especially when working on multiple projects or repositories.