Remotes and the GitHub flow

A remote is another copy of the repository, usually on GitHub. Push your commits up, pull other people's down, and learn why a push gets rejected.

Goal#

Understand origin, fetch, pull and push, fix a rejected push without a mess, and know the pull request flow.

Remotes in one table#

Command	What it does
`git clone URL`	copy a repository, and remember it as `origin`
`git fetch`	download new commits from `origin`; change nothing of yours
`git pull`	fetch, then merge `origin/main` into your `main`
`git pull --rebase`	fetch, then replay your new commits on top of `origin/main`
`git push`	send your commits up; only works if you have everything it has

origin/main is your copy of where main was on origin the last time you fetched. git status compares the two: "ahead by 1" means you have a commit to push.

Quest 06#

The quest has a real remote, origin.git, a folder playing the part of GitHub. Your teammate pushed a commit after you cloned, and you made a commit too.

shell

quest start 6

Go into the laptop folder inside it and push:

output

 ! [rejected]        main -> main (fetch first)
error: failed to push some refs to '.../git-good/06-remotes/origin.git'
hint: Updates were rejected because the remote contains work that you do not
hint: have locally. This is usually caused by another repository pushing to
hint: the same ref. If you want to integrate the remote changes, use
hint: 'git pull' before pushing again.

Git refuses to throw away your teammate's work. Get it first with git pull --rebase, which puts your commit after theirs in a straight line, then push. Look at git log --oneline --graph --all before and after. Then quest check.

The GitHub flow#

How most teams work on GitHub:

Pull main, then make a branch: git switch -c add-cat-facts.
Commit in small steps, and push the branch: git push -u origin add-cat-facts.
Open a pull request: on github.com, or with gh pr create from the GitHub CLI.
Teammates review the diff and comment; CI runs the tests; you push fixes to the same branch.
Merge on GitHub, then git switch main and git pull.

Check it works#

origin.git has both commits in a straight line, and your laptop matches it.
quest check passes.

Exercise#

Start the quest again and fix it with plain git pull instead. Draw the graph: where did the merge commit come from? Then set git config --global pull.rebase true if you prefer straight lines.

More to try

git remote -v shows where origin points. Add a second remote with git remote add.
git fetch, then git log main..origin/main lists what is waiting for you before you pull.

Quest 06

quest start 6
# ...fix it with real git...
quest check

Mark it done once quest check shows every line as PASS. Your progress stays in this browser.