Git & Gitlab

# Collaboration with git & Gitlab

---

# Why _git_

**Change control**
- keep track of who changed what
- revert changes easily
```bash
no more presentation_v2_final_FINAL.pptx
```

**Backup & distribute**
- store important files remotely
- easily copy and maintain on different devices
- share and edit with collaborators
```bash
no more inconsistent state
```

**Focus**
- strict version control helps you to work goal oriented 
```bash
no more chaotic changes
```

---

# Installing _git_
Download *git* for your operating system from [https://git-scm.com/downloads](https://git-scm.com/downloads)

---

# Local workflow with Command Line

---

# Creating a local repository
open your `Git-Bash`

create a new directory
```bash
mkdir mywebsite
```

change into that directory
```bash
cd mywebsite
```

turn this folder into a git repository
```bash
git init
```

---
# Checking your local repository
you check the status of your repository using
```bash
git status
```

which should give you 
```bash
On branch master

No commits yet

nothing to commit (create/copy files and use "git add" to track)
```
---

# Change something & commit it
In your folder `mywebsite` create a file `helloworld.html` with the content

```html
<html>
	<body>
		<h1>Hello World!</h1>
	</body>
</html>
```

check how git sees that file
```bash
git status
```

which tells you that there are
```bash
No commits yet

Untracked files:
  (use "git add <file>..." to include in what will be committed)
	helloworld.html

nothing added to commit but untracked files present (use "git add" to track)
```

---

# Change something & commit it
so let's follow the advice and do

```bash
git add helloworld.html
```

and then **commit** this change

```bash
git commit -m 'add my first file'
```
you can always check everything you did with
```bash
git log
```

```bash
commit 3b5616d1ba962e7a2e4af1f1bdd54f5d65d4e22d (HEAD -> master)
Author: Oscan Openness <oscar@freedom.org>
Date:   Sun Jan 12 12:20:28 2020 +0100

---

# Remote workflow with Gitlab

---

# Login to gitlab

create an account (with switch edu) if you have none

---

# Create a gitlab project (1/2)

---

# Create a gitlab project (2/2)

---

# Finish setup gitlab

create a password in the settings  
add an SSH key (optional)

---

# Finish local setup

(skip the `git init`, `git add .` and `git commit -m "Initial commit` steps)

---

# Add a readme

explain your project for others and your future self

---

# Add a license

everything you write has Copyright  
Copyright gives you exclusive rights (no one can use it without permission)

use a license to define permissions for others  
MIT to allow usage without restrictions  
GPL to allow usage if basic freedom granted to users  
(many others)

---

# Github Desktop to simplify

---

# Install github desktop

download from https://desktop.github.com/ 
then open your repository folder

---

# Pull changes

download the changes made on gitlab

---

# Commit changes

change your local file  
then preview the changes and then commit

---

# Push changes

push the changes

---

# View history

see the changes you've made in the past

---

# Introduction done

play around with it!  
we are here to answer questions.

inspiration:
- add some of your documents to git
- change two files but only commit one
- revert changes

ressources:
- https://education.github.com/git-cheat-sheet-education.pdf
- https://git-scm.com/book/en/v2

in 30 Minutes we will start with advanced topics.

---

# Advanced topics

best-practices for commits  
create branch & merge request  
create issue & mention it in commit  
use SSH key  
fork & merge back into origin  
add different remotes

---

# Best practices for commits

- single purpose
```bash
Improve best practice slide
```
- short, imperative subject line
```bash
Add best practice slide
```
- tell why, not how
```bash
Make wording on slides consistent
```

---

# Create branch & merge request

- create branch
```bash
git checkout -b new-branch
```
- push
```bash
git push --set-upstream origin new-branch
```
- merge (on gitlab)

---

# Create issue & mention it in commit

- create issue on gitlab
- commit local change with `#1` for `1` the issue number
```bash
git commit -m "resolve #1"
```
- push
- go to the issue on gitlab.com and observe

---

# Use SSH key

- create SSH key
```bash
ssh-keygen -t rsa -b 4096 -C "florian.moser3@uzh.ch" && eval $(ssh-agent -s) && ssh-add ~/.ssh/id_rsa
```
- copy `~/.ssh/id_rsa.pub`
- add the public key on gitlab.com
- clone with SSH
- try out push/pull to see it working