Wrapped in a single session, you'll find the concepts and techniques that convert the average Git practitioner into a master of the craft. We'll go from technical topics like "efficient conflict resolution" and "effective code cleanup," to the often-asked "how to handle project dependencies with Git" and "how to manage massive repositories." And much more.

1. #atlassian

2. Becoming a Git Master:
Concepts and Techniques to convert you
into a master of the DVCS craft
NICOLA PAOLUCCI • DEVELOPER ADVOCATE • ATLASSIAN • @DURDN

3. Becoming a Git Master:
Concepts and Techniques to convert you
into a master of the DVCS craft
NICOLA PAOLUCCI • DEVELOPER ADVOCATE • ATLASSIAN • @DURDN

4. Marcus Bertrand
Tim Pettersen
I'm George. George McFly.
I'm your density… I mean,
your destiny
Stefan Saasen
Sarah Goff Dupont

5. Let’s Become Git Pros!

6. Here you’ll learn:
PRO ALIASES & PROMPT
HIDING STUFF
CONFLICT RESOLUTION TIPS
POLISH YOUR CODE
PREVENT TAMPERING
PROJECT DEPENDENCIES

7. A pro command prompt

8. PRO ALIASES & PROMPT
Everyone has their favorite, but!
Liquid prompt is awesome
http://bit.do/liquid-prompt

9. PRO ALIASES & PROMPT
Everyone has their favorite, but!
Liquid prompt is awesome
http://bit.do/liquid-prompt

10. Crafting Awesome Aliases

11. Aliases are stored in
.gitconfig

12. In a section prefixed:
[alias]

13. PRO ALIASES & PROMPT
Basic Alias Form
Very simple:
ls = log --oneline
[vagrant@vagrant-ubuntu-trusty-64:/home/vagrant/buildstep] master ± git ls
90aa814 Merge pull request #85 from marqu3z/master
f1eb16b overwrite source.list
e6b9d16 change repo before prepare task
8bc10c0 Fix for deprecated repository
e34d861 Link to buildpacks.txt instead
4502635 Merge pull request #76 from elia/fix-72-no-buildpack-bundle-install
38be796 Bundle install ain't needed against the buildpack

14. PRO ALIASES & PROMPT
You can do great things with just this
For example: amend the last commit with
everything I have here uncommitted and new
caa = commit -a --amend -C HEAD

15. You can’t pass parameters
to simple aliases :(

16. Or can you?!

17. muahahhahahhaha
hahahahahahahha
hahahhahahahah!

18. PRO ALIASES & PROMPT
For multiple commands or complex
parameters use a bash function!
You can escape to a shell with ! like this:
my_alias = "!f() { <command> }; f”

19. PRO ALIASES & PROMPT
Some useful shortcuts and variables
More in any bash manual
$1 - first command line parameter
$2 - second command line parameter
$@ - all command line parameters passed

20. Ma, it’s the mini-DSL
I always wanted!

21. PRO ALIASES & PROMPT
What can you do with this?
Cool cool things, for example add a Bitbucket remote:
git remote add $1 https://bitbucket.org/$2.git;

22. PRO ALIASES & PROMPT
ra = "!f() {
}; f"
What can you do with this?
Cool cool things, for example add a Bitbucket remote:
git remote add $1 https://bitbucket.org/$2.git;

23. PRO ALIASES & PROMPT
ra = "!f() {
}; f"
What can you do with this?
Cool cool things, for example add a Bitbucket remote:
git remote add $1 https://bitbucket.org/$2.git;
git ra jsmith jsmith/prj

24. PRO ALIASES & PROMPT
ra = "!f() {
}; f"
What can you do with this?
Cool cool things, for example add a Bitbucket remote:
git remote add $1 https://bitbucket.org/$2.git;
git ra jsmith jsmith/prj

25. PRO ALIASES & PROMPT
Get all the alias goodness on Bitbucket
http://bit.do/git-aliases

26. Powers of invisibility
© http://www.amigosdosbichos.org/

27. Powers of invisibility
© http://www.amigosdosbichos.org/

28. Tell git which files
or folders to ignore
in .gitignore

29. What if the file is
already committed?!

30. muahahhahahhaha
hahahahahahahha
hahahhahahahah!

31. POWERS OF INVISIBILITY
Hide files from
Different from .gitignore, it hides committed files
git update-index --assume-unchanged <file>
very useful with git-svn

32. POWERS OF INVISIBILITY
Hide files from
Revert it with:
git update-index --no-assume-unchanged <file>
remember to add --no

33. POWERS OF INVISIBILITY
List assumed unchanged files
git ls-files -v | grep ^h
Useful as alias (see alias list from before)

34. Conflict Resolution Tips

35. Conflict Resolution Tips

36. What is a conflict?

37. PRO ALIASES & PROMPT
A word on terminology
What do ours and theirs mean when solving conflicts?
Current checked
out branch
!!!
--ours

38. PRO ALIASES & PROMPT
A word on terminology
What do ours and theirs mean when solving conflicts?
Current checked
out branch
!!!
--ours
Commit coming in
(i.e. via merge)
!!!
--theirs

39. PRO ALIASES & PROMPT
A word on terminology
What do ours and theirs mean when solving conflicts?
Current checked
out branch
!!!
--ours
Commit coming in
(i.e. via merge)
!!!
--theirs

40. PRO ALIASES & PROMPT
Basics for easy conflict resolution
The common commands are:
$ git checkout --ours/--theirs <file>
Check back out our own/their own version of the file

41. PRO ALIASES & PROMPT
Basics for easy conflict resolution
The common commands are:
$ git checkout --ours/--theirs <file>
Check back out our own/their own version of the file
$ git add <file>
Add the change to the index will resolve the conflict

42. PRO ALIASES & PROMPT
Aliases for easy conflict resolution
Add these to [alias] in .gitconfig:
git checkout --ours $@ && git add $@;

43. PRO ALIASES & PROMPT
Aliases for easy conflict resolution
Add these to [alias] in .gitconfig:
ours = "!f() {
git checkout --ours $@ && git add $@;
}; f"

44. PRO ALIASES & PROMPT
rerere resolve!
Reuse Recorded Resolution will help you when
dealing with repetitive and similar merge conflicts.
$ git config --global rerere.enabled true
Turns it on and forget about it

45. PRO ALIASES & PROMPT
Sample output rerere
$ git add hello.rb
$ git commit
Recorded resolution for 'hello.rb'.
[master 68e16e5] Merge branch 'i18n'

46. PRO ALIASES & PROMPT
Sample output rerere
$ git add hello.rb
$ git commit
Recorded resolution for 'hello.rb'.
[master 68e16e5] Merge branch 'i18n'
Auto-merging hello.rb
CONFLICT (content): Merge conflict in hello.rb
Resolved 'hello.rb' using previous resolution.

47. Cover your tracks (aka polish your code)

48. Cover your tracks (aka polish your code)

49. POLISH YOUR CODE
What is a rebase?
It’s a way to replay commits, one by one,
on top of a branch
MASTER
FEATURE

50. POLISH YOUR CODE
What is a rebase?
It’s a way to replay commits, one by one,
on top of a branch
MASTER
FEATURE

51. POLISH YOUR CODE
What is a rebase?
It’s a way to replay commits, one by one,
on top of a branch
MASTER
FEATURE

52. POLISH YOUR CODE
What is a rebase?
It’s a way to replay commits, one by one,
on top of a branch
MASTER
FEATURE

53. POLISH YOUR CODE
What is a rebase?
It’s a way to replay commits, one by one,
on top of a branch
MASTER
FEATURE
Don’t use!

54. POLISH YOUR CODE
What is a rebase?
Correct way to use rebase to update a
feature branch
MASTER
FEATURE

55. POLISH YOUR CODE
What is a rebase?
Correct way to use rebase to update a
feature branch
MASTER
FEATURE

56. POLISH YOUR CODE
What is an --interactive rebase?
It’s a way to replay commits, one by one,
deciding interactively what to do with each
PICK!
SQUASH
REWORD!
FIXUP
EDIT !
EXEC

57. POLISH YOUR CODE
--autosquash
Automatically modify the todo list of
rebase --interactive by annotating commits
$ git config --global rebase.autosquash true
Turns on the feature

58. POLISH YOUR CODE
--autosquash
You can prepend commit messages with:
git commit -m “squash! …"
git commit -m “fixup! …"
git commit -m “reword! …"
etc…
Rebase task list will be then prepopulated

59. CUSTOMARY
WARNING!
rebase rewrites history!
Treat this power with great care.
Only rewrite history of local branches or…

60. Prevent tampering

61. Always a balancing act
Security DevSpeed

62. PREVENT TAMPERING
Lock down your repo
Edit .git/config in the [receive] section:
# no rewriting history
denyNonFastForwards = true
!
# no deleting history
denyDeletes = true
!
# check object consistency
fsckObjects = true

63. Reject force push,
Luke
Git project has already an update hook
‘update-paranoid’ that is designed to
reject history rewriting updates
http://bit.do/update-paranoid

64. Reject force push,Luke

65. Reject force push,Luke

66. PREVENT TAMPERING
Impersonating Authors is easy
with
$ git commit -m "I'm Luke"
$ git commit --author "Elvis <elvis@graceland.net>" -m "I'm elvis"
commit a9f0967cba236465d6cb68247..
Author: Elvis <elvis@graceland.net>
Date: Mon Apr 22 18:06:35 2013 -0500
!
I'm Elvis
!
commit d6eb7572cbb4bdd8e2aaa5c90..
Author: Luke <luke@tatooine.com>
Date: Mon Apr 22 18:04:54 2013 -0500
!
I'm Luke

67. PREVENT TAMPERING
Finally you can sign/verify tags
git tag -s <tag_name> -m “message”
Sign a tag with your GPG key
git tag -v <tag_name>
Verifies that the signature is valid

68. Signing release tags is often
all you need

69. PREVENT TAMPERING
Aside on GPG
The GNU Privacy Guard
GnuPG allows to encrypt and sign your data and
communication, features a versatile key management system.

70. PREVENT TAMPERING
Harden up by signing things
Sample gpg commands to get you started:

71. PREVENT TAMPERING
Harden up by signing things
Sample gpg commands to get you started:
gpg --gen-key
Generate your GPG keys

72. PREVENT TAMPERING
Harden up by signing things
Sample gpg commands to get you started:
gpg --gen-key
Generate your GPG keys
gpg -k
List your keys

73. PREVENT TAMPERING
Harden up by signing things
Sample gpg commands to get you started:
gpg --gen-key
Generate your GPG keys
gpg -k
List your keys
gpg -a --export <keyid>
Export your key

74. PREVENT TAMPERING
Hide files in raw objects
The way the Linux kernel hackers do it
git hash-object -w <file>

75. PREVENT TAMPERING
Hide files in raw objects
The way the Linux kernel hackers do it
actually writes into the object db
git hash-object -w <file>

76. PREVENT TAMPERING
Hide files in raw objects
The way the Linux kernel hackers do it
actually writes into the object db
git hash-object -w <file>
Remember to associate a tag to
it or it will be garbage collected

77. PREVENT TAMPERING
Store your signature in
Simple! Add a tag referencing your public key
gpg -a --export <keyid> |
git hash-object -w --stdin
Store your public key in a raw object

78. PREVENT TAMPERING
Store your signature in
Simple! Add a tag referencing your public key
gpg -a --export <keyid> |
git hash-object -w --stdin
Store your public key in a raw object
git tag nicks-key 65704f3…
Tag the raw object with a label

79. PREVENT TAMPERING
Store your signature in
Simple! Add a tag referencing your public key
gpg -a --export <keyid> |
git hash-object -w --stdin
Store your public key in a raw object
git tag nicks-key 65704f3…
Tag the raw object with a label
raw object id

80. PREVENT TAMPERING
Import other public keys
git cat-file -p tims-key | gpg --import
Import a GPG key from a tag

81. PREVENT TAMPERING
Finally you can sign/verify tags
git tag -s <tag_name> -m “message”
Sign a tag with your GPG key
git tag -v <tag_name>
Verifies that the signature is valid

82. and Project Dependencies

83. How do you handle
project dependencies
with ?

84. Splitting up a project
is painful, for so many
reasons

85. Use a build/dependency
tool instead of

86. GIT AND PROJECT DEPENDENCIES
I’ll give you an incomplete list of examples!
Java
Nodejs
Javascript
Python Pip easy-install
Ruby

87. GIT AND PROJECT DEPENDENCIES
I’ll give you an incomplete list of examples! (2)
C#
C++ c-make
Objective C
PHP
Go godep

88. Another possibility:
use git submodule

89. Another possibility:
use git subtree

90. Use other build
and cross-stack
dependency tools

91. GIT AND PROJECT DEPENDENCIES
For example you can check out:
•Android Repo (http://bit.do/android-repo)
•Repobuild (chrisvana / repobuild)
•Chromium depot_tools (http://bit.do/depot-tools)
•Facebook Buck (http://facebook.github.io/buck/)
•Twitter Pants (http://bit.do/twitter-pants)

92. PRO ALIASES & PROMPT
Review these ideas online
http://bit.do/git-deps

93. Thank you!
NICOLA PAOLUCCI • DEVELOPER ADVOCATE • ATLASSIAN • @DURDN

94. POWERS OF INVISIBILITY
Hide files from
• Level One
• Level Two
• Level Two
• Level Two
• Level One
CODE FONT:
<html xmlns="http://www.w3.org/1999/xhtml">

95. POWERS OF INVISIBILITY
Page title here
• Level One
• Level Two
• Level Two
• Level Two
• Level One

96. Page title here
• Level One
• Level Two
• Level Two
• Level Two
• Level One

97. Page title here
Page Title Here
• Level One
• Level Two
• Level Two
• Level Two
• Level One

98. Page title here
• Level One
• Level Two
• Level Two
• Level Two
• Level One

100. Caption goes here

101. Just text by itself,
for impact.

102. Just text by itself,
for impact.

103. Just text by itself,
for impact.

104. Just text by itself,
for impact.

105. Just text by itself,
for impact.

106. Type Quote Here And Move Both Quotation
Marks To The Beginning And End Of The
Quote. Lorem Ipsum Dolor Sit Amet, Conse
Cetur Ading Elit.
DAVID HANDLY, GLOBOCHEM
”
“

107. Big cool statistic 2,569 Add-Ons in Marketplace

109. 60
45
30
15
0
2007 2008 2009 2010
Region 1 Region 2 Region 3
Page title here

110. 40%
30%
20%
10%
2007 2008 2009 2010
Page title here

111. Page title here
COLUMN TITLE COLUMN TITLE COLUMN TITLE
Content Content
Content Content
Content Content
Content Content
Content Content