Use Git Like a Boss

Kevin W. Gisi

Chicago Code Camp 2—May 1, 2010
Iowa Code Camp 5—May 1, 2010

Summary

Move out Subversion; there's a new man in town. Learn how a decentralized version control system can help make your workflow easier, regardless of what language you use. We'll walk through how to manage a project using Git, and use some branching, tagging, recovery, and a host of other features along the way. Come see how easy it is to branch and merge without the usual headaches.

Big Day

Use Git Like the Godfather

I'm going to make you an offer you can't refuse

Centralized Versioning

Centralized Versioning

Use Git Like Douglas Reynholm

This is very important. I have a vital meeting to attend, and I've just shot myself in the leg.

Use Git Like Donald Trump

Let's talk merger.

Use Git Like Linus Torvalds

I decided I can write something better than anything out there in two weeks. And I was right.

Basic Git Syntax

git init
git add .
git commit -m "Initial commit"

Subsequent Commits

Add then commit:

git add newfile.txt
git add trackedfile.txt
git commit -m "Updated trackedfile, added newfile"

Shorthand:

git commit -am "Added all changes to tracked files"

Distributed Versioning

Distributed Versioning

• No more tiers
• Will of the people
• Accountability
• Security
• Redundancy

Grabbing Remote Repositories

Grab a remote repository:

git clone git://github.com/gisikw-slides/use-git-like-a-boss.git
cd use_git_like_a_boss/

Collaborating with Remotes

Pull changes:

git pull origin master

Push changes

git push origin master

Use Git Like Mr. Spacely

In the future, we use GitHub!

Distributed in the Wild

Distributed in the Community

Distributed in the Office

Multiple Working Copies

Git Branches

git branch gh-pages
git checkout gh-pages
  #> Switched to branch "gh-pages"
slideshow slides.md
git commit -am "Generated slides"
  #> [master 0adc9ff] Generated slides
  #> 0 files changed, 0 insertions(+), 0 deletions(-)
  #> create mode 100644 slides.html
  #> create mode 100644 slides.pdf
  ...

Switching Branches

git checkout master
  #> Switched to branch "master"
ls
  #> slides.md
  #> Rakefile

Use Git Like Michael Scott

They say a cluttered desk means a cluttered mind.

Feature-Based Branches

• master
• experimental
• gh-pages
• growl_notifications
• irc_notifications
• remote_control

Use Git Like Jimmy James

You want my advice? Well I'm not going to give it to ya.

Merging with Git

git checkout master
  #> Switched to branch "master"
git merge experimental
  #> Auto-merging conference.rb
  #> Merge made by recursive.

When Things Go Wrong

CONFLCIT (content): Merge conflict in conference.rb Automatic merge failed; fix conflicts and then commit the result.

Conflict Files

class Conference
  def best_presentation
<<<<<<< HEAD
    "Kevin's, of course"
=======
    "Ola Bini's talk"
>>>>>>> experimental
  end
end

Fixed File

class Conference
  def best_presentation
    "Kevin's, of course"
  end
end

Committing the Fix

git commit -am "Fixed merge conflict, Kevin's presentation is vastly superior"

Use Git Like Bill Lumbergh

Actually, given that we can merge instantaneously, I'm not gonna need you to come in on Saturday anymore. Yeah..........

Steal Branches

Stealing Branches

git branch --track muwahaha milton/stapler
  #> Branch muwahaha set up to track remote branch stapler from milton.
git checkout muwahaha
  #> Switched to branch 'muwahaha'

Pushing and Pulling Branches

git pull milton stapler
  #> Pull the stapler branch into the current system
git push milton stapler
  #> Push the current system to the stapler branch

Corporate Doesn't Adopt

Bob is excited about Git!

Use Git Like Bob Kelso

This is not "Take Your Problems to Work Day". It's just "Work Day"

Git-SVN

git svn clone https://svn.kde.org/home/kde/trunk/kdesupport/strigi
  #> SCREEN SPAM OF ADDED FILES
cd strigi
...

Git-SVN

Push commits to Subversion:

git svn dcommit

Pull changes from Subversion:

git svn rebase

Use Git Like Mr. Burns

This is the type of trickery I pay you for.

Fixing Mistakes

git reset --hard
  # Discard everything since the last commit
git reset --hard ORIG_HEAD
  # Discard the most recent successful merge
git reset --soft HEAD^
  # Undo the last commit - keep the changes locally
git commit --amend
  # Redo the last commit, with additional changes

Oh Yeah, There's...

• .gitignore

• Tagging

• Shashing

• Submodules

• Hooks

Centralized Culture

The Cathedral:

• Commit when you're done

• Merging is expensive - limit your branching

• Always have server access

• I am the SERVER thy God. Thou shalt have no stranger servers before Me.

Decentralized Culture

The Bazaar:

• Commit is equivalent to auto-save

• Branch for everything - don't convalute features

• Keep the repository local

• Use external servers as common points, but remember that there is no single "right way" to write code

Use Git Like the PHB

Additional Resources

• Pragmatic Version Control Using Git by Travis Swicegood
• http://help.github.com
• GitCasts

Thank you!

Kevin W. Gisi <kevin@kevingisi.com>