Steps to setup and use

To push code to a GitHub repository using a personal access token (PAT) from a Linux system, follow these steps:

1. Generate a Personal Access Token (PAT)

• Go to your GitHub account settings.
• Navigate to Developer settings > Personal access tokens > Tokens (classic).
• Click Generate new token (classic).
• Select the necessary permissions (e.g., repo for full control of private repositories).
• Generate the token and copy it (you won’t be able to see it again after closing the page).

2. Clone the Repository (if not already cloned)

If you haven't cloned the repository yet, use the following command:

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

Replace username with your GitHub username and repository with the repository name.

3. Configure Git to Use the Personal Access Token

Instead of using your GitHub password, you'll use the PAT for authentication.

• Navigate to the repository directory:

cd repository

• Update the remote URL to include the PAT:

git remote set-url origin https://<TOKEN>@github.com/username/repository.git

Replace <TOKEN> with your personal access token, and username/repository with your GitHub username and repository name.

Example ( not a real token) :

git remote set-url origin https://ghp_1234567890abcdef1234567890abcdef1234@github.com/username/repository.git

4. Add, Commit, and Push Your Changes

• Stage your changes:

git add .

• Commit your changes:

git commit -m "Your commit message"

• Push your changes to the repository:

git push origin main

Replace main with the branch name if it's different.

5. Optional: Store the Token Securely

If you don't want to include the token in the remote URL, you can use a credential helper to store it securely:

• Install the Git credential helper:

sudo apt-get install git-credential-manager

• Store the token:

git config --global credential.helper store

• Push your changes, and Git will prompt you for your username and password. Use your GitHub username and the PAT as the password.

Notes

• Always keep your PAT secure and avoid sharing it.
• If you encounter issues, ensure the token has the correct permissions and is not expired.

Troubleshooting

If you're still encountering an authentication error when trying to push code to GitHub using a personal access token (PAT), let's troubleshoot step by step. Here are some common issues and solutions:

1. Verify the Personal Access Token (PAT)

• Ensure the PAT is correctly generated with the necessary permissions (e.g., repo for full control of private repositories).
• Check if the token has expired. If it has, generate a new one.
• Make sure you're using the correct token format. It should look something like this: ghp_123456789786876876f123456789def1234 ( not a real token).

2. Check the Remote URL

Ensure the remote URL is correctly set to include the PAT. Run the following command to check the current remote URL:

git remote -v

The output should look like this:

origin  https://<TOKEN>@github.com/username/repository.git (fetch)
origin  https://<TOKEN>@github.com/username/repository.git (push)

If it doesn't, update the remote URL as follows:

git remote set-url origin https://<TOKEN>@github.com/username/repository.git

Replace <TOKEN> with your PAT and username/repository with your GitHub username and repository name.

3. Use the Correct GitHub Username

When prompted for a username, use your GitHub username (not your email). The password is the PAT.

4. Check for Two-Factor Authentication (2FA) Issues

If you have 2FA enabled on your GitHub account, you must use a PAT instead of your GitHub password. Ensure you're using the PAT correctly.

5. Test Authentication with curl

To verify that your PAT is working, you can test it with curl:

curl -H "Authorization: token <TOKEN>" https://api.github.com/user

Replace <TOKEN> with your PAT. If the token is valid, this command will return your GitHub user details.

6. Use a Credential Helper

If you don't want to include the PAT in the remote URL, you can use Git's credential helper to store the token securely:

• Enable the credential helper

git config --global credential.helper store

• Then push your changes. Git will prompt you for your username and password:

  • Username: Your GitHub username.
  • Password: Your PAT.

  This will store the credentials in a file (e.g., ~/.git-credentials) for future use.

7. Check for Proxy or Firewall Issues

If you're behind a proxy or firewall, it might block the connection to GitHub. Configure Git to use the proxy:

git config --global http.proxy http://proxyuser:proxypassword@proxy.server.com:port

Replace proxyuser, proxypassword, proxy.server.com, and port with your proxy details.

8. Debugging with GIT_CURL_VERBOSE

Enable verbose logging to get more details about the error:

GIT_CURL_VERBOSE=1 git push origin main

This will show detailed HTTP request and response information, which can help identify the issue.

9. Common Errors and Fixes

• Error: remote: Invalid username or password:
  • Ensure you're using the correct PAT and username.
  • Regenerate the PAT if necessary.
• Error: remote: Repository not found:
  • Verify the repository URL and ensure the PAT has access to the repository.
• Error: 403 Forbidden:
  • Check if the PAT has the correct permissions (repo scope).

10. Alternative: Use SSH Instead of HTTPS

If you're still having trouble, consider using SSH instead of HTTPS for authentication:

• Generate an SSH key and add it to your GitHub account.
• Update the remote URL to use SSH:

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

• Push your changes:

git push origin main

References

• Github PAT Docs.