Git and Git Workflow

Install Git and Create a GitHub account.

• Linux

  $ sudo apt-get install git

  $ sudo yum install git

• Windows and Mac
  • https://git-scm.com/downloads

GitHub account

• www.github.com

What is Git?

• Git is a free and open source version control system
• It's a system that keeps records of your changes
• Allows collaboration and lets you see who made what changes as well as when those changes were made
• Git lets you revert any changes and go back to a previous version of a project

What's so special about Git?

• Distributed version control system
  • Git doesn't rely on a central server to store all versions of a project
  • Every developer gets and full history of the project when they "clone"
• Users can make any changes without an internet connection
• An internet connection is required only to push and pull from a remote server

Key Concepts

• Snapshot: The way git tracks changes to the code
  • At a given time you can create a snapshot of the current version of the code
• Commit: The act of creating a snapshot. (Commits also keeps track of the previous commit that came before it)
  • So an open source project is just made up of a bunch of commits
• Repository: Usually a collection of the project along with its full history (usually on a remote server, GitHub)
• Cloning: The act of copying a repository from a remote server
• Pulling: Downloading new changes from a remote repository that doesn't exist in your local repository
• Pushing: Adding your local changes to a remote repository
• Branches: All commits on git exists on a branch
  • The main branch in a project is called the master branch

(https://www.atlassian.com/git/tutorials/using-branches)

(https://nvie.com/posts/a-successful-git-branching-model/)

Typical Git project

(https://git-scm.com/book/en/v2/images/branch-and-history.png)

• Head: reference to the current branch in the workspace (in this case we are working in the master branch)
  • It is also a reference to most recent commit (most of the time)

Branching

• Typically it is best to not directly work on master
  • The master branch is the main branch, so it must be your most stable branch
  • All developers who will work on a project will initially branch off of the master branch
• Branching off: is the concept of making a new branch using the latest commit of another branch

- Merge: Once you feature is complete, merge the changes in the branch back in to master

(https://www.atlassian.com/git/tutorials/using-branches)

Git cheat sheet

(https://services.github.com/on-demand/downloads/github-git-cheat-sheet.pdf)

Typical Git workflow

1. Pull latest code from the remote server
2. Write some new code or edit some existing code
3. Add file to the staging area
4. Commit changes with readable commit message
5. Push the commit
6. Repeat

(https://www.atlassian.com/git/tutorials/comparing-workflows/gitflow-workflow)

So now, what is GitHub?

• The largest git repository hosting service
• Allows code collaboration with anyone and has some handy UI tools to easily manage your repository

Open Source and GitHub

• There are hundreds of thousands of project available for developers to contribute

Typical open source Git workflow

1. Fork or Pull latest code from the remote server
2. Write some new code or edit some existing code
3. Add file to the staging area
4. Commit changes with readable commit message
5. Push the commit
6. Create a Pull request to the original repository
7. Repeat

(https://guides.github.com/introduction/flow/)