Git Workshop

# Git Workshop
### <a href='https://github.com/janusvm'>Janus Valberg-Madsen</a>
### 2018-10-22 @ Aalborg University

---

# Overview of today

1. What is version control, and why should I care?

1. Overview of the most important Git functions

1. Overview of GitHub

1. Live demo showcasing the concepts

1. **(interactive)** Install Git and a client

1. **(interactive)** Set up a repository on GitHub for your P1 project

1. Exercises (if there's time left)

---

# Why use a version control system (VCS)?

- You have an annotated history of changes

- It makes collaboration easy

- It provides you with a full backup of your project

- Unlike on services like Dropbox, conflicts are structured and easily resolved

## Why Git, specifically?

- Distributed (as opposed to centralised)

- Most popular ⟹ all problems have been had

- GitHub

---

# Git concepts (functions)

---

## The main components of a Git repository

---

## Add: stage changes for committing

---

## Commit: append staged changes to history

---

## Push: changes on local repo ⭢ remote repo

---

## Push: changes on local repo ⭢ remote repo (before)

---

## Push: changes on local repo ⭢ remote repo (after)

---

## Pull: changes on remote repo ⭢ local repo (before)

---

## Pull: changes on remote repo ⭢ local repo (after)

**Fetch**

- "Safe" alternative to push
- Downloads commits _without_ applying them to the working tree

---

## Branches

- Branches are simply labels pointing to commits

- Git uses these labels to move around in the commit history

---

---

---
layout: true

## Checkout: switch to a different branch

---

---

---
layout: false

## Merge: apply changes from a different branch

---

## Overview

---

# <img src="imgs/octicons/mark-github.svg" height="44" width="44" alt="icon"> GitHub

---

## View and comment on commits

---

## Keep track of tasks with project boards

---

## Workflow

---
name: demo
class: center, middle, inverse

# Time for a demo
⤷ on Windows with GitHub Desktop

---

# Time to set up Git and GitHub

⤷ and get your project repository ready to go

---

### Windows and macOS

Download from <https://git-scm.com/>

Windows users may have to restart after installation to update the system PATH

### Linux

Install via package manager, e.g.

```sh
sudo apt install git
```
]

[Many options](https://git-scm.com/downloads/guis/), but to highlight a few:

♟ [**GitHub Desktop**](https://desktop.github.com/)

⤷ very simple client, only most basic features; integrates with GitHub

♜ [**GitKraken**](https://www.gitkraken.com/)

⤷ more features, fancy UI; free for _non-commercial_ use, requires account or GitHub sign-in

♛ **Your editor of choice**

⤷ many editors support version control from inside the editor<br>
.small[(e.g. Emacs with Magit, or Vim with Fugitive)]

♚ **The command line** 😏
]

---
name: github

# Collaborate with GitHub

❗
signing up with uni email ⟹ free private repos

## Getting started

1. Go to [**github.com**](https://github.com) and sign up with your `@student.aau.dk` email

2. Go to [**education.github.com/pack**](https://education.github.com/pack) and click _Get your Pack_

---
layout: true

## Setting up a repository (for the repo owner)

_NB: Only one person from each group needs to set up a project repository_

---

1. On GitHub, log in and click .gh-btn[<img src="imgs/octicons/repo.svg" height="20" width="20" alt="icon">New]

1. Fill in the details;

- **Repository name:** P1
    - **Description:** P1 project for Group `<your group id>`
    - **🗹 Private** (can be set later, if you don't have the student discount yet)
    - **🗹 Initialize this repository with a README**
    - **Add .gitignore:** TeX

1. Go to .gh-menu[<img src="imgs/octicons/gear.svg" height="20" width="20" alt="icon">Settings] 🠪 .gh-menu[Collaborators]

1. Add each of your group members as a collaborator

1. Go to .gh-menu[<img src="imgs/octicons/code.svg" height="20" width="20" alt="icon">Code] and click .gh-btn[Clone or download<img src="imgs/octicons/chevron-down.svg" height="20" width="20" alt="icon">]

1. Click .gh-menu[Open in Desktop] to get started (or copy the URL and open it with your Git client, if you don't use GitHub Desktop)

---

1. Download a template from [**janusvm.github.io/aau-project-template**](https://janusvm.github.io/aau-project-template/)

1. Unpack it in the folder where you cloned the project

1. In GitHub Desktop (or whatever client you use), stage all the new files

1. Commit with a message like "Add project template files"

1. Push to GitHub

---
layout: false

## Setting up a repository (for the collaborators)

1. Go to the repository page on GitHub (github.com/owner/repo)

1. Click .gh-btn[Clone or download <img src="imgs/octicons/chevron-down.svg" height="20" width="20" alt="icon">]

1. Clone the repository (by clicking .gh-menu[Open in Desktop] with GH Desktop, or by using the URL with another client)

After this, you're ready to start writing!

---

## Remember the workflow

1. **Pull** from GitHub to get the latest changes from the other group members

1. Work on the project

1. **Add** and **Commit** related changes together

1. **Pull** again, in case new commits have been pushed in the meantime

1. If there are any conflicts, resolve them and commit the merge

1. **Push** your changes to GitHub, so the other group members can get them

---

# Exercises

## Links and help

- These slides: [janusvm.github.io/aau-git-workshop](https://janusvm.github.io/aau-git-workshop)

- Very simple introduction to Git: [think-like-a-git.net](http://think-like-a-git.net/)

- More comprehensive tutorials: [www.atlassian.com/git/tutorials](https://www.atlassian.com/git/tutorials)

- Tips on writing commit messages: [chris.beams.io/posts/git-commit](https://chris.beams.io/posts/git-commit/)

- Fixing mistakes: [sethrobertson.github.io/GitFixUm/fixup.html](http://sethrobertson.github.io/GitFixUm/fixup.html)

- Google .gh-menu[:^)]

Feel free to ask questions too!