This document provides an introduction to using Git version control. It discusses key Git concepts like distributed version control, objects in Git like blobs and trees, and commands like add, commit, branch, merge, rebase, fetch and push. The introduction includes an agenda, sources for further information, and demos several Git workflows and commands.

1. INTRODUCTIONTO GIT
Drupal Camp LA 2015
Matthew Wrather
Wrather Creative

2. RACONTEUR
BONVIVANT
MAN OF MYSTERY
matt@wrathercreative.com
@mwrather

3. SOURCES
• A great talk by @merlyn himself, Randal Schwartz CC-BY-SA
• OnVimeo at https://vimeo.com/35778382
• Slides at http://slidesha.re/z7nQrG
• Pro Git by Scott Chacon CC-BY-NC-SA
• Read for free at http://git-scm.com/book
• And many more at http://lmgtfy.com/?q=git+tutorial

4. AGENDA
1.Why UseVersion Control
2. Git basic concepts
3. Demo
Time for questions after each section.

5. DOESN’T USEVERSION CONTROL
slworking on Flickr
CC-BY-NC-SA

6. WHAT IS GIT FOR?
Git is for…
• Tracks a tree of related files
• Distributed
• High Performance
• Easy & Fast Branch/Merge
• Good Data Integrity
• Collaborative
Git is not for…
• Tracking unrelated files
• Tracking File Metadata
• Binary Files

8. DEMO

9. WRAPYOUR MIND AROUND
• Distributed:Your repository is complete unto itself.
• Anyone can commit!*
*To their own repo.
• (Once you start fetching and pushing work,
permissions come into play.)
• There can still be a central, blessed repo.
• Universal Public Identifiers: SHA1 hashes

10. OBJECTS IN GIT
• Blobs (actual data)
• Trees (directories of blobs or of other trees)
• A commit, which is:
• A tree
• Zero or more parent commits
• Metadata (commit message, name email, timestamp)

11. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA

12. QUESTIONS?

13. WE NEEDTOTALK
ABOUT COMMITMENT
Do this
Work
Stage
Commit
here
Filesystem
Staging Area
Repository
(aka here)
WorkingTree
Index
HEAD
by
writing code
git add
git commit
Rinse and Repeat

14. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
BRANCHES

15. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
BRANCHES
$ git commit

16. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
BRANCHES
$ git branch testing

17. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
BRANCHES

18. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
BRANCHES
$ git checkout testing

19. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
BRANCHES
$ subl awesome.module
$ git add awesome.module
$ git commit -m ‘changed awesome module’

20. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
BRANCHES
$ git checkout master

21. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
BRANCHES

22. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
MERGING

23. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
MERGING
$ git checkout -b iss53 # shortcut for:
$ # git branch iss53
$ # git checkout iss53

24. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
MERGING

25. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
MERGING

26. FAST FORWARD MERGE
$ git checkout master
$ git merge hotfix

27. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
FAST FORWARD MERGE

28. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
FAST FORWARD MERGE

29. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
FAST FORWARD MERGE
$ git branch -d hotfix

30. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
RECURSIVE MERGE

31. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
RECURSIVE MERGE
$ git checkout master
$ git merge iss53

32. DEMO

33. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
REBASING

34. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
REBASING

35. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
REBASING

36. graphic from Pro Git by Scott Chacon
CC-BY-NC-SA
REBASING
$ git checkout experiment
$ git rebase master

37. Thou shalt not rebase commits that you
have pushed to a remote repository.

38. REMOTE REPOSITORIES
• All these things that we’ve done so far happen in the privacy
of our own computer and don’t affect anything else.
• As a beginner, you are going to be using other people’s
repositories more than you are going to create your own
git clone <remoteUrl>
• <remoteURL> can be HTTP, SSH, or git:// depending on your
permissions

39. REMOTE REPOSITORIES
• When you copy a repo using the git clone command,
you’ll automatically have a remote called origin
• It’s possible to have many, many remotes. It can be hard to
keep track of.You probably don’t need to worry about it.

40. REMOTE REPOSITORIES
• When you’ve done working, you can “push” your work up to a
remote repository
git push <remote-nickname> <branch>
git push origin master
• But if someone else has done work and pushed it to the
remote repo, git won’t let you overwrite.

41. REMOTE REPOSITORIES
• To find out what’s on the server, you can “fetch” from a
remote repository
git fetch <remote-nickname>
git fetch origin
• Remote branches will be tracked locally, prefixed with the
remote nickname.The master branch on origin becomes
origin/master locally.

42. REMOTE REPOSITORIES
$ git push origin master
[git error message]
$ git fetch origin
$ git merge origin/master
$ git push master
[HUGE SUCCESS!]

43. DEMO

44. QUESTIONS?

45. THANKYOU!
Matthew Wrather • @mwrather
matt@wrathercreative.com • (510) WRA-THER