reveal.js

Intro to Git & GitLab

What is Git?

Git is a version Control system for tracking changes in computer files

Why do we need it?

Goals of Git

Accessible	Everyone can contribute!
Distributed	Enable large and distributed teams to collaborate
History	Every change is tracked

The Lingo!

Repository	Database where files are stored and managed
Server	The computer that stores your repo
Client	The computer you use to connect to the server
Local Copy	Repo files you keep on your computer to make changes

More Lingo!

Master	The primary location for code in the repo
Branch	An independent line of development
Fork	A copy of the repo
Merge	Add changes from one file into another

Check your computer for Git

						
							$ git --version

** No need to type in the $, this just indicates it is a shell command.

*INSTRUCTOR: Walk participants through commands on screen **explain that they do not have to type in the $, this just indicates it is a shell command.

It is time to get started. Let's check and see if you have Git. Run appropriate command to check. The command is the same for Mac or Windows.

If your terminal responds with a message like this: "git version 2.0.1", you have an official version installed.

If you're prompted to install Xcode, or the command line developer tools, you either do not have git installed, or don't have it in your $PATH variable.

For Mac users: If you get a message like "git version 1.9.3 (Apple Git-50)", you have Git installed from Apple (through Xcode or the command line developer tools), and can most likely benefit from installing the latest build directly from the official Git website.

Download Git: https://git-scm.com/downloads

Check for a default name Git will use when you commit

							
								$ git config --list

Set the default name Git will use when you commit

							
								$ git config --global user.name "First Name Last Name"

Set the default email Git will use when you commit

							
								$ git config --global user.email "email@example.com"

** The quotes are necessary! They indicate that the words inside the quotes are a string and not a command.

View your config settings

						
							$ git config --list

First, let's get our bearings.

						
							$ ls

If you are in your root directory
you should see something like this.

If you are not in your root directory, no worries. Run this!

							
								$ cd ~/

Make your first Git Repo!

						
							$ mkdir my-first-repo

Move into your new repo

							
								$ cd my-first-repo

Initialize your repository with Git

							
								$ git init

Once you are sure you are in your root directory, go ahead and run the following command to make your very first repository *INSTRUCTOR: You may want to explain that it is OK to CD to their Desktop, or another directory to create this folder.

Next, use the 'Change Directory' command to move inside the directory you just made. You must be inside a folder to initialize Git.

Initialize your Git repository by running 'git init.' This command creates an empty Git repository. You should see a notice on the command line telling you. "Initialized empty Git repository in /Usesr/..."

*INSTRUCTOR: A lot is going on behind the scenes here that may be overwhelming for those just learning. A .git directory with the necessary subdirectories and an initial HEAD file is created. In short, this is everything needed to create a master branch and start tracking changes.

Let's check the status of our Git Repo.

						
							$ git status

Let's create a file and add it to your repo.

						
							$ touch my-file.txt

View the file by running the list command.

							
								$ ls

Tell Git to track our file. Then check it's status

							
								$ git add my-file.txt
								$ git status

Time to commit!

						
							$ git commit -m "initial commit"

Phew! That was a lot. Let's review !

init	Create an empty Git repository or reinitialize an existing one
config	Get and set global or repo options
status	Show the working tree status
add	Adds the file contents to the index
commit	Add the changes from one file to another, bringing them up-to-date

Let's look at what we've done

						
							$ git log

							
							commit [UNIQUE HASH] (HEAD -> master)
							Author: Your Name 
							Date:   [DATE]
								
								initial commit
							(END)

Let's make a local mistake .

							
								$ git checkout my-file.txt

Nobody's perfect. Let's walk through how to handle mistakes.

Earlier, we created a text file and committed it to be tracked by git. Open that file using notepad/text-edit (right click=> Open with).

Now, type something into the file and save it (ctrl+S).

Whoops! We made a mistake. We didn't mean to change that file. What can we do?!

In the terminal, type the command 'git checkout my-file.txt.' This command will update the files in your root working directory to match the version in the index.

Go ahead and check it. Close the text file (if still open) and then reopen it. The text you typed in should be gone. But Why?

You made changes to the file but never committed them to the index. Until you commit them, they only exist locally. It is important to remember this as you work with Git. Remember to commit your changes frequently.

Let's make a staged mistake .

							
								$ git add my-file.txt

Let's fix it !

							
								$ git reset HEAD my-file.txt

What happens if you added the file already? Remember, once a file is added, it is 'staged' in the index. That means Git is aware there has been a change added but not committed.

Let's give it a try. Open your text file again and add some text.

Next, add it to Git using 'git add.'

Whoops! We didn't want to add that. How do we fix it?

Run the next command, 'git reset HEAD my-file.txt.'

You should see a notification in the terminal which says: Unstaged changes after reset: my-file.txt

This command tells Git to unstage the file and set the index of the file back to the last HEAD. HEAD is the name given to the commit from which the working tree's current state was initialized. Your changes still exist in the file but they are no longer staged in the index. Running git status will show the unstaged changes. *INSTRUCTOR: This may take further exposition as HEAD can be a confusing idea for beginners)

Let's make a commited mistake .

							
								$ git add my-file.txt
								$ git commit -m "changing and commiting text"

Let's fix it !

							
								$ git log
								$ git reset HASH or git reset --hard HASH

What happens if you committed the file already? Remember, once a file is committed, it is logged in the index.

Let's give it a try. Open your text file again and add some text.

Next, add it using 'git add.'

Next, commit it using 'git commit.'

Whoops! We didn't want to add that. How do we fix it?

Run the command, 'git log.' This command will output the hash# belonging to the latest commits. Remember the hash? It is the unique 40 character # Git gives to each commit. It's about to come in very handy!

Copy the commit Hash for the commit BEFORE the bad one we just made, then type in ':q' to exit the log.

Type in the command 'git reset' followed by the hash number you just copied. You should immediately see the output on the command line stating: 'On branch master nothing to commit, working tree clean.'

What just happened? Well, we had already committed the change which meant that we could not simply checkout the file to undo the change. We had to go a step further and tell Git to reset the last commit. This command rewinds your repository’s history all the way back to the specified hash. git reset preserves the working directory, the commits are gone, but the contents are still on disk. Revert is the safest option, but sometimes, you’ll want to “undo” the commits and the changes in one move—that’s what --hard does.

Git & GitLab

Git ≠ GitLab

GitLab

GitLab is open source, users can host Git repositories publicly and privately for free.
GitLab has one vision. Everyone can contribute to all digital content.
Open source projects host or mirror their repositories on GitLab.
Post your own code for others to use or contribute to.
Use and learn from the code in other people's repositories.

GitLab's Awesome Features

Unlimited private projects and collaborators.
Built-in CI/CD
Preview your changes with Review Apps
Publish static websites for free with GitLab Pages
Public projects and groups get all gold plan features for free

Setup Account with GitLab

https://gitlab.com

First look at GitLab

Add your SSH key

https://docs.gitlab.com/ee/ssh/README.html

Check for an existing SSH key

Windows Command Prompt:

							
								$ type %userprofile%\.ssh\id_rsa.pub

Git Bash on Windows / GNU/Linux / macOS / PowerShell:

							
								$ cat ~/.ssh/id_rsa.pub

Existing SSH key

							
								➜  ~ cat ~/.ssh/id_rsa.pub
								ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAA.....

Generate a new SSH key pair

Git Bash on Windows / GNU/Linux / macOS / PowerShell:

							
								$ ssh-keygen -t rsa -C "your.email@example.com" -b 4096

							
								Generating public/private rsa key pair.
								Enter file in which to save the key (/Users/yourname/.ssh/id_rsa):

Passphrase

							
								Created directory '/Users/yourname/.ssh'.
								Enter passphrase (empty for no passphrase):
								Enter same passphrase again:

Your key

							
								Your identification has been saved in /Users/yourname/.ssh/id_rsa.
								Your public key has been saved in /Users/yourname/.ssh/id_rsa.pub.
								The key fingerprint is:
								9b:7c:c0:e2:62:74:bf:6b:85:4f:61:8f:d31:0:ef:b7 your.email@example.com
								The key's randomart image is:
								+--[ RSA 2048]----+
								|      .          |
								| o  +  .         |
								| .  o So B       |
								|  . o +. += + .  |
								|    o .. E +. o  |
								|  . . B . o      |
								|      .o .       |
								+-----------------+

Copy the public SSH key

macOS:

							
								$ pbcopy < ~/.ssh/id_rsa.pub

Windows Command Line:

							
								$ type %userprofile%\.ssh\id_rsa.pub | clip

Git Bash on Windows / Windows PowerShell:

							
								$ cat ~/.ssh/id_rsa.pub | clip

Add your key to your profile

GitLab Groups

GitLab Projects

Forking a Project

Success!

You should now see the forked project under your username. *INSTRUCTOR: It may be helpful to point out the breadcrumbs that now show the project under their username.

Forking a project has two purposes. It allows you to suggest changes to the existing project. In this case, you would make changes to your local copy and create a merge request to have them pushed 'upstream' to the original. A forked project can also be used as a starting point for your own. In many instances, people will 'fork' a boilerplate project to give them a jump-start on their own.

The latter is what we are doing today. We do not want to push changes back to the original repo. Instead, we want to play around with this on our own.

So, before we start, let's remove the forked relationship.

Remove Forked Relationship

Settings/General

Settings/General/Advanced

Remove Forked Relationship

Confirmation Modal

Success!

Cloning

Clone locally

								
									$ git clone PASTE SSH HERE

Check clone

								
									$ ls

Move into the directory

								
									$ cd NAME-OF-PROJECT-OR-FILE

Create a new branch & checkout

								
									$ git checkout -b BRANCHNAME

Create branch only

								
									$ git branch BRANCHNAME

Make a change

Open up the README.md file using your favorite code editor.

We have our branch, let's go ahead a make a change to one of the files. This repo contains the presentation you see today, developed using reveal.js. Don't worry! You don't need to know any programming to make a change. We are going to make a simple change to the README file.

The README file contains information about the directory and its contents. The README file for this repo is written in markdown, a lightweight markup language with plain text formatting syntax.

Open the README file in an editor of your choice. *INSTRUCTOR: You may have to walk individuals through this process. They should have an editor like Atom, Sublime, or Visual Code installed already.

*INSTRUCTOR: Instruct the class to make a change at the end of the README file. It doesn't matter what it is. Add their name, a sentence, or delete content. Make sure they hit save!

Check git status

								
									$ git status

Output

								
									modified: README.md

Stage file for tracking

								
									$ git add README.md

Check status

								
									$ git status

Output

								
									modified: README.md

Time to commit!

								
									$ git commit -m "details of the change made"

Check status

								
									$ git status

Output

								
									On branch [BRANCHNAME]
									Your branch is ahead of 'origin/[BRANCHNAME]' by 1 commit.
										(use "git push" to publish your local commits)
									nothing to commit, working tree clean

Let's push!

								
									$ git push

Error!

								
									fatal: The current branch test-branch has no upstream branch.
									To push the current branch and set the remote as upstream, use
									
										git push --set-upstream origin [BRANCHNAME]

Set Origin

							
									$ git push --set-upstream origin [BRANCHNAME]

							
									Branch [BRANCHNAME] set up to track remote branch test-branch from origin

Our First Merge Request

Fill in the details

You have several options here. You can change the title and add a description. These can help others quickly understand what this merge request is all about.

Further down, you can assign a particular person to review your merge request. Most teams have a process for who reviews and merges these requests.

You can assign a milestone. Milestones allow you to organize issues and merge requests into a cohesive group, with an optional start date and an optional due date.

Labels can be added to tag the merge request. Labels provide an easy way to categorize the issues or merge requests based on descriptive titles like bug, documentation or any other text. They can have different colors, a description, and are visible throughout the issue tracker or inside each issue individually.

At the very bottom of the page, you will see the 'Source Branch' and the 'Target Branch.' The 'Source Branch' is the branch you are on., It is the 'source' of the changes. The 'Target Branch' is the branch into which the changes will be merged. It is the 'target' for the changes.

Merge your Merge Request

See your Changes

Success!

Checkout Master

							
								$ git checkout master

Sync with Master

								
									$ git pull

Check Status

								
									$ git status

Intro to Git & GitLab

What is Git?

Why do we need it?

Goals of Git

Accessible

Distributed

History

The Lingo!

Repository

Server

Client

Local Copy

More Lingo!

Master

Branch

Fork

Merge

Check your computer for Git

Check for a default name Git will use when you commit

Set the default name Git will use when you commit

Set the default email Git will use when you commit

View your config settings

First, let's get our bearings.

If you are in your root directory you should see something like this.

If you are not in your root directory, no worries. Run this!

Make your first Git Repo!

Move into your new repo

Initialize your repository with Git

Let's check the status of our Git Repo.

Let's create a file and add it to your repo.

View the file by running the list command.

Tell Git to track our file. Then check it's status

Time to commit!

Phew! That was a lot. Let's review !

init

config

status

add

commit

Let's look at what we've done

Let's make a local mistake .

Let's make a staged mistake .

Let's fix it !

Let's make a commited mistake .

Let's fix it !

Git & GitLab

Git ≠ GitLab

GitLab

GitLab's Awesome Features

Setup Account with GitLab

First look at GitLab

Add your SSH key

Check for an existing SSH key

Windows Command Prompt:

Git Bash on Windows / GNU/Linux / macOS / PowerShell:

Existing SSH key

Generate a new SSH key pair

Git Bash on Windows / GNU/Linux / macOS / PowerShell:

Passphrase

Your key

Copy the public SSH key

macOS:

Windows Command Line:

Git Bash on Windows / Windows PowerShell:

Add your key to your profile

GitLab Groups

GitLab Projects

Forking a Project

Success!

Remove Forked Relationship

Settings/General

Settings/General/Advanced

Remove Forked Relationship

Confirmation Modal

Success!

Cloning

Clone locally

Check clone

Move into the directory

Create a new branch & checkout

If you are in your root directory
you should see something like this.