GitHub

GitHub is a web-based platform that provides hosting for Git repositories. It’s much more than just a place to store code; it’s a comprehensive platform for collaboration, version control, project management, and open-source development. Think of it as a “cloud service for Git” plus a social network for developers.

Key Features of GitHub:

  • Remote Repository Hosting: Store your Git repositories securely in the cloud.
  • Collaboration Tools: Work with others on projects, manage contributions, track issues, and discuss changes.
  • Issue Tracking: Report bugs, request features, and manage tasks.
  • Pull Requests: Propose changes to a project and have them reviewed by others before merging. This is a core part of the GitHub workflow.
  • Code Review: Discuss and review code changes within pull requests.
  • Project Management: Use features like projects, milestones, and labels to organize and track work.
  • Wiki and Documentation: Create documentation for your projects.
  • GitHub Pages: Host static websites directly from your GitHub repositories.
  • GitHub Actions: Automate workflows, including CI/CD pipelines.
  • Community and Open Source: Discover, contribute to, and learn from millions of open-source projects.
  • Profile Page: Having a profile page that shows your activity.

Getting Started with GitHub

  1. Create a GitHub Account: Go to https://github.com/ and sign up for a free account.

  2. Create a Repository: Follow the “Hello World” tutorial on GitHub: Hello World. This will guide you through creating your first repository on GitHub (your remote repository).

  3. Link Your Local Repository to GitHub:

    • If you already have a local Git repository, you can link it to a newly created empty GitHub repository using the git remote add command:

      git remote add origin [https://github.com/your_username/your_repository_name.git](https://github.com/your_username/your_repository_name.git)  # Replace with your username and repo name
git remote -v  # Verify the remote URL

    • If you’re starting a new project, it’s often easier to clone the GitHub repository to your local machine (see the “Cloning” section below).

    Explanation:

    • git remote add origin ...: Adds a “remote” named origin to your local repository. origin is a conventional name for the primary remote repository (you can have multiple remotes).
    • https://github.com/your_username/your_repository_name.git: This is the URL of your GitHub repository (you can find this on the repository’s page on GitHub).

Cloning a Repository

Cloning creates a local copy of a remote repository (on GitHub or elsewhere).

  • Methods:

    • HTTPS: 
      git clone [https://github.com/user/repo.git](https://github.com/user/repo.git)

      You will be prompted for your GitHub username and password (or personal access token) when you push changes.

  1. Set up Git with your GitHub Account 
    git config --global user.name "Your Name"
git config --global user.email "youremail@email.com"

  2. Generate SSH key (Recommended for security)

    SSH: (Recommended)

      git clone git@github.com:user/repo.git

    This requires setting up an SSH key (see below). SSH is more secure and convenient than HTTPS for frequent interactions.

    GitHub CLI:

      gh repo clone user/repo

    Requires installing the GitHub CLI (https://cli.github.com/). This is a convenient way to interact with GitHub from the command line.

  • Recommendation: Set up an SSH key for GitHub. This avoids repeatedly entering your username and password.

Integrating Your GitHub Account with Your Local Git

To interact with GitHub repositories (push, pull) without repeatedly entering your credentials, you need to configure your local Git installation.

  1. Check Credentials to see if they are correct

  2. Set Your Git Username and Email:

        git config --global user.name "Your Name"
    git config --global user.email "[email address removed]"

Linking your local repo to GitHub

This section will guide you in the case that you have a local repository (project on your computer) and you want to save it to a remote repository (save it to the cloud).

  1. Initialize or navigate to your repo

     # Find your repository
 cd /your_repo_path

 # or initialize a new repo
 git init
  2. Add the remote repository
    • Go to your github and create a new repo, click the green code button and copy the link…
    • using HTTPS: 
         git remote add origin https://github.com/your-username/repository-name.git
    • using SSH: 
         git remote add origin git@github.com:your-username/repository-name.git

  3. Verify the remote link

    git remote -v

    You should see something along the lines of:

    origin  https://github.com/your-username/repository-name.git (fetch)
origin  https://github.com/your-username/repository-name.git (push)
  4. Push your local files to the remote repository
    • If you have files to push 
      git add .
git commit -m "Initial commit"
git push -u origin main

Note: If you are working with other people, PLEASE AVOID CONFLICTS…

  1. Get the latest updates from the remote repository 
    # Downloads changes without merging them to your local repo
git fetch origin

  2. Merge or Rebase If you are okay with your changes

    git merge origin/main

# or rebase
git rebase origin/main

  3. Or Pull (Fetch and Merge in one command)

    • This will fetch and merge changes for you automatically.
    • If conflicts occur, Git will ask you to resolve them before completing the merge.
    git pull origin main

Cloning Repositories

Say you need to collaborate with another developer. In this case you will clone their repo onto your system so that you can make your changes. This can be done by clicking the green code button, which will open a dropdown menu. You should see…

  • HTTPS: the easiest and most common way to clone a repo, but it requires authentication to push changes. 
    git clone https://github.com/user/repo.git
  • SSH: uses a key that you set up to your account, this makes your life easier and lets you push without needing authentication. This method is faster and more secure than HTTPS. 
    git clone git@github.com:user/repo.git
  • GitHub CLI: you can clone quickly if you have GitHubCLI installed. This removes the need to manually enter a URL 
    gh repo clone user/repo

Recommendation: Set up an SSH key for GitHub to make pushing and pulling projects easier, avoiding repeated authentication prompts. Since you’re likely copying the clone URL from GitHub anyway, the GitHub CLI’s URL-free cloning isn’t a major advantage. SSH is your best bet for long-term convenience.

Steps to clone

  1. Clone the Repo

    • Via HTTPS:
    git clone https://github.com/your-username/repository-name.git
    • Via SSH:
    git clone git@github.com:your-username/repository-name.git

  2. Make your changes and check what files you modified

    git status

  3. Check if your files have been tracked and then Commit and Push

    git add <files you created>
# or you can add all the modified files with 'add .'
git add .

#check your working area to make sure the files are tracked
git status

#push all your changes
git commit -a -m "Created files X,Y,Z and changed A,B,C"

# You would ideally be working on your own branch: Denoted as Your_Branch
git push origin Your_Branch

  4. Validate your changes with

    git log

Unlinking a Remote Repository

In the event that you want to disconnect your local machine from a remote repository you can follow the steps below. This can be useful if you are done working on a project and you don’t want to accidentally push some changes, or if you accidentally duplicated a repository that you don’t need.

Remove the Remote Origin 

git remote remove origin

Verify the removal with

git remote -v

Important: Use the email address associated with your GitHub account. The --global flag sets these configurations for all your Git repositories. You can set them per-repository by omitting --global.

  1. Generate an SSH Key (Recommended for Security and Convenience):

    ssh-keygen -t ed25519 -C "[email address removed]"  # Use ed25519 for a more modern key type (recommended over RSA)
    • Follow the prompts:
      • Press Enter to accept the default file location (~/.ssh/id_ed25519).
      • Enter a strong passphrase (highly recommended).
    • This command creates two files:
      • ~/.ssh/id_ed25519: Your private key (keep this secret!).
      • ~/.ssh/id_ed25519.pub: Your public key (this is what you’ll add to GitHub).
     # add SSH key to SSH Agent
 eval "$(ssh-agent -s)"
 ssh-add ~/.ssh/id_ed25519

  2. Add Your Public Key to GitHub:

    • Copy the contents of your public key file:

      cat ~/.ssh/id_ed25519.pub  # Display the public key

    • Go to your GitHub account settings:

      1. Click on your profile picture (top right).
      2. Select “Settings.”
      3. In the left sidebar, click “SSH and GPG keys.”
      4. Click “New SSH key.”
      5. Give the key a descriptive title (e.g., “My Laptop”).
      6. Paste the contents of your public key into the “Key” field.
      7. Click “Add SSH key.”

  3. Verify Your Configuration:

    git config --list          # List your Git configuration
git remote -v             # List your configured remote repositories (should show the SSH URL if you're using SSH)
ssh -T git@github.com     # Test your SSH connection to GitHub

    Expected output for ssh -T git@github.com:

    Hi username! You've successfully authenticated, but GitHub does not provide shell access.