Introduction to Git

1. Introduction

Course Goals

• What is version control and why is it important
• Configuring git, using git config
• git init and the .git directory
• Tracking a change with git add, git commit
• Viewing repository status with git status
• Adding a remote with git remote
• Pushing changes to the remote git push

Poll

• How many folks have used git at all before?
• How many folks have a GitHub account?

Git Caveats

• Git is powerful
• Git has a terrible user design
• Git is hard to fully learn by yourself
• Git (like any other tool) takes time and practice to get good

Setup

• This is a 2 hour interactive session, there is so much more to learn!
• Please type along!
• You will need:
  • A terminal with git installed
  • A text editor
  • A GitHub account
• Suggested setup: 2 "desktops" or "spaces", one with your editor and one with your terminal

2. What is Version Control

SC: Automated Version Control

VC Through Naming

VC in Parallel

Key Features

• Version control is unlimited undo (but not at a granular level)
• Version Control allows many people to work in parallel

Other VC Systems

from Pro Git by Scott Chacon and Ben Straub

How Git Works

from Pro Git by Scott Chacon and Ben Straub

Key Git Feature

• The deltas are important
• Represent a distinct set of changes
• Accompanied by a commit message

3. Configuring Git

SC: Setting Up Git

Configuring from the Command Line

git config --global user.name "Ada Lovelace"
git config --global user.email "ada@lovelace.io"
git config --global core.editor "emacs -nw"
git config --global init.defaultBranch main

Help with Config

git config --list
git config --help
cat ~/.gitconfig

Current Config ~/.gitconfig

[core]
    editor = emacs -nw
[init]
    defaultBranch = main
[user]
    name = Ada Lovelace
    email = ada@lovelace.io

4. Networking Activity

Working Example

• We are going to create a "database" or repository of people you've met at the summer school
• We will track changes using git and keep it all on GitHub
• The following slides are simple instructions that you need to work through, follow along with me!

Activity: Make Friends

• Create a new file to track your friends, including first name and institution
  • I am Elsa from Lawrence Livermore National Lab
• Start tracking this file with Git
• Put this on GitHub
• Talk to your neighbor and add them to your file
  • don't forget to commit your changes
• Talk to a different neighbor and add their information
• Add hobbies to your entries

Activity: Friends Challenge

• Open just your text editor on your laptop
• Swap laptops with a neighbor
• Make a change (addition and/or deletion) to the file in front of you
• Swap back
• What changed??

Watch me!

• Figure out what has changed
• Commit changes in separate hunks

5. Continue Your Journey

This is just the beginning

• More things to learn:
  • branching
  • collaboration through "pull" or "merge" requests
  • platforms: GitHub and GitLab

Git Hosting Services

• GitHub, GitLab, BitBucket, and many more
• Additional concepts: permissions, "pull request" or "merge request"
• Additional tools: issue tracking, wiki, web/documentation hosting, CI/CD

Get Social

• Sign up for GitHub
  • Follow your friends, star your favorite projects
  • If you follow me this week I will follow you back
• Use GitHub to showcase projects (may need to get permission)
• Use GitHub to collaborate and network

Activity: GitHub Secret

• Create a new repo called username
• Add a README.md file
• Visit your GitHub Profile (github.com/username)

Git Lessons

• Software Carpentry: Git Novice
• Git Cheetsheet
• GitLab: Use Git Tutorials
• Atlassian (BitBucket): Learn Git

Advanced Git Resources

• GitHub Skills
• Learn Git Branching Interactively
• Choose your own adventure: undoing, fixing, or removing commits in git

6. Credits

Content inspired by Software Carpentry's Version Control with Git course.

Created with Emacs, Org Mode, and RevealJS.