introduction to git workshop

Introduction To Git Workshop

Tom Aratyn

Get Git

• On Matrix• I have accounts for you

• On Windows• http://msysgit.github.io

• On OS X• brew install git

• On Linux• sudo apt-get install git

• Otherwise• http://git-scm.com

About Me

Django and JavaScript Developer

Founder @ The Boulevard PlatformEngineer @ FoxyProxy

Created open source projects:BitBucket Release Note Generatordjango-email-changerExploit Me Suite

Why Git?

Git is• Small• Fast• Distributed• Free & Open Source• Trusted• Linux• Homebrew• Everyone on GitHub + Gitorious +

Not Just For Code (but mainly for code)

http://government.github.com

About Today

What we will cover• Creating Repos• Checking Out• Committing• Basic Branching • Basic Merging• Pushing & Pulling

What we won't• git reset

• Changing history

• Rebasing• Adding/Removing

Remotes• Partial Staging• Fetch• Tags

Making A Git Repository

Normal Repository Bare Repository Cloned Repository

Normal Repository A git repository with a working directory

Normal Repository Exercise

$ git init workshop.normal.git

Bare Repository

A git repo without a working directory(this is what you want on the repo)

Bare Repository Exercise

$ git init --bare workshop.bare.git

Cloned RepositoryA normal repository is a copy of a remote repository and setup to work with it.

Cloned Repository Exercise

$ git clone workshop.bare.git workshop.git$ cd workshop.git

Image By: Scott Chacon, Pro Git

Staging Files

Before a file can be added it must be staged

Staging File Exercise

$ mvim index.html$ git add index.html

What’s The Status Of My Files Right Now?

$ git status# On branch master## Initial commit## Changes to be committed:# (use "git rm --cached <file>..." to unstage)## new file: index.html#

Committing Files

Committing means that we want in the version control system.All staged files will be committed.

Commit File Exercise

$ git commit –m "My initial commit"

Commit File Exercise Result

Committer: Tom Aratyn <mystic@nelson.local>Your name and email address were configured automatically basedon your username and hostname. Please check that they are accurate.You can suppress this message by setting them explicitly:

git config --global user.name "Your Name" git config --global user.email you@example.com

After doing this, you may fix the identity used for this commit with:

git commit --amend --reset-author

1 file changed, 0 insertions(+), 0 deletions(-) create mode 100644 foo

The Log

Git keeps a log of everything you commit, who wrote authored it, and who committed it.

View The Git Log Exercise

$ git log$ git log --graph$ gitk

(Don’t worry there are better GUIs, more on that later)

Why isn't your name there?

The Parts Of A Log

List of commits and branch pointersA commit is made up of:• SHA1 id• Message• Files• Author• Committer

Configuring git

git is configured in two places:~/.gitconfigyoureRepo/.git/config

Configuring Git Exercise

$ git config --global user.name "Your Name"$ git config --global user.email you@example.com

Configuring Git Exercise Result

$ cat ~/.gitconfig[user]

name = Tom Aratyn email = "tom@aratyn.name"

Changing History

There are many ways to change history in git.

We're only going to look at one way:

Amend the last commit.

Change The Last Commit Exercise

$ git commit --amend -m "initial commit with an html file"$ # has the author changed?$ gitk

Author Vs. Committer

Git is made from from the ground up for multiple developer projects (Linux).Large projects often distinguish between the author (who wrote the patch/code) and the committer (who let it into the blessed repository)

Update the Author Exercise

$ git commit --amend --reset-author# why did the screen change ?# type in ":wq" to leave vim.

How To Remove A File?

What if we committed a file we no longer need can we get rid of it?

Yes & No

Yes, You Can Remove ItFrom the current (and future) versions.

No, It'll Be In Past VersionsThe whole point of version control is you can always recover old files.

Remove A File Exercise

$ git rm index.html$ ls$ #Notice how the file is now gone$ git status $ #Notice how the file is staged$ git commit -m "Removed index.html"

Practice: Adding a fileCreate another index.html and commit it

Branching

Fast and easy branching is git's killer feature.

Branches let development progress on multiple fronts separately and simultaneously.

Check Your Branch Exercise

$ git branch$ git branch –a$ # What's the difference between the two commands?

Create A Branch Exercise

$ git branch workshop-example$ git branch$ # what branch are you on?

Switch Branch Exercise

$ git checkout workshop-example$ git branch$ # now what branch are you on?

Switch To A New Branch Immediately Exercise

$ git checkout -b fix-bug-123$ git branch$ gitk

Making A Change On A Branch Exercise

$ # edit index.html$ git add index.html$ git commit -m "Added some initial html"

Merging

Merging is really git's killer featureBecause branching without merging is pretty useless

See CVS

Merging Process

1. Go to the branch you want to merge into• Often the branch you branched off of.• Usually "master" or "develop"

2. Do the merge

Two Three types of merges

1. Fast Forward Merge2. Basic Merge

a. Conflicted Merge

Fast Forward Merge

Only available when the branch can be cleanly applied onto your current branch

Fast Forward Merge Exercise

$ # (assuming you have a change on fix-bug-123 - use gitk to check)$ git checkout master$ git merge fix-bug-123$ gitk

Basic Merge Exercise

Prep

Add add a div on the master branchChange the title on the fix-bug-123 branch

Recall

git checkoutgit addgit commit

Basic Merge Exercise

$ git checkout master $ git merge fix-bug-123$ git log --graph --decorate --all

Conflicted Merge Exercise

Prep

Change the same line on both branches(change the class on the same div)

Recall

git checkoutgit addgit commit

Conflicted Merge Exercise

$ git checkout master$ git merge fix-bug-123$ git status$ # edit index.html$ git add index.html$ git commit $ git log --graph --decorate --all

Sharing Is Caring

So far everything we've done is on the same repo but projects need to be shared.

Git lets you push your changes to others and pull the changes others made.

Pushing Exercise

$ # Recall that we cloned our bare repo$ git push origin master$ cd ../workshop.bare.git $ git log

Pulling Exercise

Prep

1. Clone the bare repo again• Call it workshop.2.git

2. Commit a change to workshop.git

3. Push the change

Recall

git clonegit addgit commitgit push

Pulling Exercise

$ cd ../workshop.2.git$ git branch$ git pull$ git log

How does pulling work?

Tracking Branches

A tracking branch is a local branch which knows that updates to a remote branch should be applied to it.

Tracking Branch Exercise

$ git checkout –t remotes/origin/fix-bug-123

About Today

What we covered• Creating Repos• Checking Out• Committing• Basic Branching • Basic Merging• Pushing & Pulling

What we didn't• git reset

• Changing history

• Rebasing• Adding/Removing

Remotes• Partial Staging

Where to next?

Learn more at from "Pro Git"http://git-scm.com/book

Start Your Project:Free Open Source Repos

http://github.com

Free Private Reposhttp://bitbucket.org

GUI: http://SourceTreeApp.com

Questions?

Thank You!

A link to this presentation will be onhttp://blog.tom.aratyn.name@themystictom@aratyn.name (I can email it to you)