JustinMorgan / git-101

Presentation materials for Git learning session

Git 101

Presentation materials for Git learning session

Part 1: Conceptual Overview

What Does Distributed Version Control Mean?

1. No central authority; the "main repository" exists, but there's nothing special about it
2. Each user has a copy of the entire change history
3. Delta-based rather than file-based - Can start from initial state and construct current state from the change history - Concurrent development is much simpler
   • Analogy: team arithmetic

Basic Git Vocabulary

1. Pull
2. Push
3. Merge
4. Commit
5. Add
6. Branch - much simpler and more important to the workflow than with TFS - more on this in the next part
7. Remote

Part 2: Branching and the Version Tree

GitFlow-Like Branching Strategy (whiteboard diagram)

1. (optional) Create fork with GitHub-style origin? Save for demo?
2. Create branch - new branch for each feature/task - all work is done in a branch
3. Make changes
4. Multiple local commits in the same branch; they're not getting pushed anywhere yet
5. Team pushes commits to master while we're working
6. Rebase branch, merge in new changes from master - keeps all this feature's commits consecutive once they're back in master - optional: squash commits with rebase -i
7. Merge branch back into master

Talking point: Ease of moving back and forth through time leads to microversioning, which leads to being able to choose any point in history and promote it to UAT/Production, which leads to continuous deployment.

Part 3: Git in Action (c9.io + GitHub demo)

Initial setup

1. Show original repo on GitHub

2. Fork: upstream/master => origin/master (origin takes the place of a Develop branch)

3. Clone: origin/master => local/master

   mv .c9 .. git clone [url] . mv ../.c9 .

- or init, remote add, pull

4. Remote

   git remote -v git remote --add upstream [url] git remote -v

- Show that we now have origin and upstream remotes, explain difference

Development

1. Branch: local/master => local/task123

   git checkout -b task123

2. Make changes: local/task123 - Edit an existing file - Add a new file and explain git add

3. Commit: local/task123

   git commit -am "[task123] I did some stuff"

4. Checkout: local/master

   git checkout master

- Show that files have changed

5. Pull: upstream/master => local/master

   git pull upstream

or 

    git pull upstream/master

6. Checkout: local/task123

   git checkout task123

- show that it hasn't changed while we were on local/master

7. Rebase: local/task123 => updated local/master

   git rebase master

or 

    git rebase -i master
    
- move local/task123 commits up to new position on local/master
- merge in all team commits between old position and new one

8. Push: local => origin 1. Option 1: push local branch to origin branch

      git push task123 origin/task123
   

2. Option 2: merge local branch down to master, push to origin/master

9. Pull request: origin/task123 => upstream/master

10. Merge to team repo on GitHub: origin/task123 => upstream/master

11. (optional) Delete branches: local/task123, origin/task123

    git branch -d task123 git branch -d origin/task123