GitHub: your account, repositories, forks and clones

Git and GitHub

Git is the tool on your machine: commits, branches, history. It works with no network at all. GitHub is a service that hosts Git repositories so a team can share them, and adds the work around code: pull requests and reviews, issues, Actions for CI/CD, releases and security scanning. GitLab and Bitbucket do the same job; the Git commands are identical on all three.

Your account, safely

Your GitHub account can push code that other people deploy, so protect it like a production login:

1. Two-factor authentication. GitHub requires it for anyone who contributes code. Use an authenticator app or a passkey, and save the recovery codes somewhere safe, not on the same laptop.
2. Keep your email private. Every commit records the author's email, and public commits stay public for good. In Settings → Emails, turn on Keep my email addresses private, and also Block command line pushes that expose my email. GitHub gives you an address like 12345678+rajeev@users.noreply.github.com; set it as your email for public work:

$ git config --global user.email "12345678+rajeev@users.noreply.github.com"

3. A profile people can read. Add your name, a photo and a short bio. Create a public repository named exactly like your username, and its README appears at the top of your profile: a good place for what you work on and links to your best projects.

Connecting your machine

Git needs to prove who you are when you push. The simplest way is the GitHub CLI, gh:

$ sudo apt install gh             # or brew install gh, winget install GitHub.cli
$ gh auth login                   # choose GitHub.com, HTTPS or SSH, log in with the browser
$ gh auth status                  # who you're logged in as, and how

gh auth login stores a token and sets Git up to use it, so git push over HTTPS just works. If you prefer SSH, make a key as in the Linux course's Networking lesson (ssh-keygen -t ed25519), add the public key in Settings → SSH and GPG keys, and test it with ssh -T git@github.com. Passwords no longer work for Git over HTTPS on GitHub; it's a token or SSH.

Creating a repository

On the website: the + menu, then New repository. Pick a name, a description, the visibility, and optionally a README, a .gitignore template and a licence.

From the command line, for a project that already exists on your machine:

$ cd ~/projects/shop
$ gh repo create shop --private --source=. --push    # create on GitHub, add origin, push
$ git remote -v
origin	https://github.com/rajeev/shop.git (fetch)
origin	https://github.com/rajeev/shop.git (push)

Or start a fresh one on GitHub and clone it straight away:

$ gh repo create notes --public --add-readme --license mit --gitignore Python --clone

Public or private?

Public means readable, not writable: strangers can't push to your repository, they can only fork it and ask you to pull their changes.

Fork or clone?

These two words get mixed up constantly. They do different things in different places:

⤢ View

Fork: a copy on GitHub. Clone: a copy on your machine. Contributors do both.© Diagram: DevOps Academy

Close

• Your team's repository (you have write access): just clone it, branch, push, open a pull request.
• Someone else's project: fork it, clone your fork, push to your fork, open a pull request to the original. The Collaboration lesson walks through it.

$ gh repo fork owner/project --clone     # fork on GitHub and clone your fork
$ git remote -v                          # origin = your fork, upstream = the original
$ git fetch upstream                     # get the original's newest commits

$ gh auth login
$ gh auth status
$ cd ~/projects/shop
$ git config user.email                 # make sure this is your noreply address
$ gh repo create shop --private --source=. --push
$ git status -sb                        # main is now tracking origin/main
## main...origin/main
$ gh repo view --web                    # opens the repository in your browser