The document discusses workflows in Git, focusing on branching models, practices, and automation tools. It covers continuous integration, collaboration through pull requests, and the implications of using either single repositories or forks in a team environment. The importance of effective branching strategies and the significance of automation in code quality and continuous delivery is highlighted throughout the presentation.

1. Real World
Workflows

3. Nicola Paolucci
Developer Advocate / Git Evangelist
I come out nice in pictures, I know :-).
durdn.com
@durdn

4. You heard
has
Cheap local branching
Full local history
10x the speed of svn
Staging area
Speed
Huge community
Feature based workflow
prominent in Open Source
cryptographic integrity
Distributed

5. ground breaking paradigm
is ground breaking

6. Workflow building blocks
fork
cheap branching
rebase
powerful merging
distributed
clone

7. Can we do a fast
Can we fix a bug for the
upcoming
RELEASE
HOTFIXrelease?
for the current
?
Can we
BUILD
the current code ?
Is the code for that
FEATURE
complete?
Has everybody
REVIEWED ?
the code for this feature

8. What we’ll cover:

9. What we’ll cover:
1
Branching models

10. What we’ll cover:
1
Branching models
2
Practices & Decisions

11. What we’ll cover:
1
Branching models
2
Practices & Decisions
3
Tooling & Automation

12. What we’ll cover:
1
Branching models
2
Practices & Decisions
3
Tooling & Automation
4
Continuous Integration

13. Which branching model?

14. 1
Which branching model?

15. Two common Branching Models

16. Two common Branching Models
1
Continuous Delivery

17. Two common Branching Models
1
Continuous Delivery
2
Product Releases

18. for Continuous Delivery

19. 1.1
for Continuous Delivery

20. Time
feature
staging
master/
production

21. staging
Time
feature
master/
production
master is in production

22. staging
Time
feature
master/
production
master is in production
staging is the next version

23. staging
Time
feature
master/
production
master is in production
staging is the next version
new features off staging
with branch names like:
username/ISSUE-KEY-summary

24. staging
Time
feature
master/
production
master is in production
PR
staging is the next version
new features off staging
with branch names like:
username/ISSUE-KEY-summary

25. staging
promoted from staging, can receive hotfixes
Time
feature
master/
production
master is in production
PR
staging is the next version
new features off staging
with branch names like:
username/ISSUE-KEY-summary

26. staging
promoted from staging, can receive hotfixes
Time
feature
master/
production
master is in production
PR
staging is the next version
new features off staging
with branch names like:
Hotfix
username/ISSUE-KEY-summary

27. staging
promoted from staging, can receive hotfixes
Time
feature
master/
production
master is in production
PR
staging is the next version
new features off staging
with branch names like:
Hotfix
username/ISSUE-KEY-summary

28. for Product Releases

29. 1.2
for Product Releases

31. 1
One Central Repository

32. master
PRJ-123-description
Time
feature
branches
1
One Central Repository
2
One Branch per Feature

33. PRJ-123-bug-description
Time
bugfix
branch
master
1
One Central Repository
2
One Branch per Feature
3
One Branch per Bugfix

34. 2.2
PRJ-345-bug-description
Time
bugfix
release
branch
master

35. master
2.2
PRJ-345-bug-description
Time
bugfix
release
branch
4
Release Branches

36. master
Long running
2.2
PRJ-345-bug-description
Time
bugfix
release
branch
4
Release Branches

37. master
Long running
2.2
PRJ-345-bug-description
Time
bugfix
release
branch
4
Release Branches
5
master is alpha / RC

38. Automatic merges for the win!

39. release
branch
release
branch
2.1
2.2
PRJ-345-bug-description
Time
bugfix
master

40. Automatic MERGES!
release
branch
release
branch
2.1
2.2
PRJ-345-bug-description
Time
bugfix
master

41. Automatic MERGES!
release
branch
release
branch
2.1
2.2
PRJ-345-bug-description
Time
bugfix
master

42. Automatic MERGES!
release
branch
release
branch
2.1
2.2
PRJ-345-bug-description
Time
bugfix
master

45. Placeholder for changes you DON’T want to merge!

46. release
branch
release
branch
2.1
2.2
2.2.1

47. release
branch
release
branch
2.1
2.2
2.2.1
2.1.4

48. release
branch
release
branch
2.1
2.2
2.2.1
2.1.4
2.1.5-SNAPSHOT

49. release
branch
release
branch
2.1
2.2
2.2.1
2.1.4
2.1.5-SNAPSHOT
We don’t want to merge
the 2.1.x version!

50. release
branch
release
branch
2.1
2.2
2.2.1
2.1.4
2.1.5-SNAPSHOT
What can we do here?
We don’t want to merge
the 2.1.x version!

51. git merge

52. git merge --strategy= resolve

53. git merge --strategy= recursive

54. git merge --strategy=

55. git merge --strategy= ours

56. stable
branch
stable
branch
2.1
2.2
2.2.1
2.1.4
2.1.5-SNAPSHOT

57. stable
branch
stable
branch
2.1
2.2
2.2.1
2.1.4
2.1.5-SNAPSHOT
$> git checkout stable-2.2
$> git merge -s ours stable-2.1

58. stable
branch
stable
branch
2.1
2.2
2.2.1
2.1.4
2.1.5-SNAPSHOT
$> git checkout stable-2.2
$> git merge -s ours stable-2.1
merge commit, content
discarded

59. Deep breath, it’s really simple

60. The secret sauce
The merge protocol

61. The secret sauce
The merge protocol
When a branch is:
Change flows from
branch to baseline:
Change flows from baseline
to branch:
More stable than its
baseline
Continuously
Never
Less stable than its
baseline
When code complete
Continuously

62. The secret sauce
The merge protocol
When a branch is:
Change flows from
branch to baseline:
Change flows from baseline
to branch:
More stable than its
baseline
Continuously
Never
Less stable than its
baseline
When code complete
Continuously

63. The secret sauce
The merge protocol
When a branch is:
Change flows from
branch to baseline:
Change flows from baseline
to branch:
More stable than its
baseline
Continuously
Never
When code complete
Continuously
Release branch
Less stable than its
baseline

64. The secret sauce
The merge protocol
When a branch is:
Change flows from
branch to baseline:
Change flows from baseline
to branch:
More stable than its
baseline
Continuously
Never
When code complete
Continuously
Release branch
Less stable than its
baseline

65. The secret sauce
The merge protocol
When a branch is:
Change flows from
branch to baseline:
Change flows from baseline
to branch:
More stable than its
baseline
Continuously
Never
When code complete
Continuously
Release branch
Less stable than its
baseline

66. The secret sauce
The merge protocol
When a branch is:
Change flows from
branch to baseline:
Change flows from baseline
to branch:
More stable than its
baseline
Continuously
Never
When code complete
Continuously
Release branch
Less stable than its
baseline

67. The secret sauce
The merge protocol
When a branch is:
Change flows from
branch to baseline:
Change flows from baseline
to branch:
More stable than its
baseline
Continuously
Never
When code complete
Continuously
Release branch
Less stable than its
baseline
Feature branches

68. The secret sauce
The merge protocol
When a branch is:
Change flows from
branch to baseline:
Change flows from baseline
to branch:
More stable than its
baseline
Continuously
Never
When code complete
Continuously
Release branch
Less stable than its
baseline
Feature branches

69. The secret sauce
The merge protocol
When a branch is:
Change flows from
branch to baseline:
Change flows from baseline
to branch:
More stable than its
baseline
Continuously
Never
When code complete
Continuously
Release branch
Less stable than its
baseline
Feature branches

70. The secret sauce
The merge protocol
When a branch is:
Change flows from
branch to baseline:
Change flows from baseline
to branch:
More stable than its
baseline
Continuously
Never
When code complete
Continuously
Release branch
Less stable than its
baseline
Feature branches
Credit: Laura Wingerd - The Flow of change

71. The secret sauce
The merge protocol
Release Branch
Master

72. The secret sauce
The merge protocol
Release Branch
Merge
continuously
Master

73. The secret sauce
The merge protocol
Release Branch
Never
Merge
merge!
continuously
Master

74. The secret sauce
The merge protocol
Release Branch
Never
Merge
merge!
continuously
Master
Backport single
changes using
git cherry-pick

75. Practices & Decisions

76. turbo boost!
2
Practices & Decisions

77. What is a Pull Request?

78. Pull Request
I have some
code here!
Hey I have some code I
want to merge here,
take a look?
Low friction
collaboration
Can I merge
it here?

79. Merge vs Rebase
Does a debate even exist?
REBASE
MERGE

80. What is a Rebase?
feature
master

81. What is a Rebase?
Merge commit
feature
master

82. What is a Rebase?
Merge commit
feature
master
feature
master

83. What is a Rebase?
Merge commit
feature
master
feature
master

84. What is a Rebase?
Merge commit
feature
master
feature
master

85. What is a Rebase?
Merge commit
feature
master
feature
master

86. Merge as team policy

87. Merge as team policy
1
Traceability

88. Merge as team policy
1
Traceability
2
At a cost: readability

89. Merge as team policy
1
Traceability
2
At a cost: readability
3
bisect debugging is harder

90. Merge as team policy
with no fast-forwards
1
Traceability
2
At a cost: readability
3
bisect debugging is harder

92. Rebase as team policy [1]

93. Rebase as team policy [1]
1
History flat and clean

94. Rebase as team policy [1]
1
History flat and clean
2
Delicate with Pull Requests

95. Rebase as team policy [1]
1
History flat and clean
2
Delicate with Pull Requests
3
Dangerous for unexperienced

96. Rebase as team policy [2]

97. Rebase as team policy [2]
4
Re-resolve similar conflicts

98. Rebase as team policy [2]
4
Re-resolve similar conflicts
5
Requires often a force push

99. Rebase as team policy [2]
4
Re-resolve similar conflicts
5
Requires often a force push
6
Loses context for feature

100. Rebase as a local cleanup

101. Rebase as a local cleanup
1
Do it

102. Rebase as a local cleanup
git rebase --interactive
1
Do it

103. Rebase as a local cleanup
git rebase --interactive
1
Do it
2
Do it

104. Rebase as a local cleanup
git rebase --interactive
1
Do it
2
Do it
3
Do it!!!!!!

105. Recommendation?

106. Recommendation?
1
If team unfamiliar, don’t rebase

107. Recommendation?
1
If team unfamiliar, don’t rebase
2
Encourage rebase as cleanup
and proper ecology

108. Recommendation?
1
If team unfamiliar, don’t rebase
2
Encourage rebase as cleanup
and proper ecology
3
Choose clean or traceable

109. Recommendation?

110. Recommendation?
4
Don’t fear the Merge! Use it!

111. Recommendation?
Explicit merges into the mainline
4
Don’t fear the Merge! Use it!

112. Recommendation?
Explicit merges into the mainline
4
Don’t fear the Merge! Use it!
git log --first-parent

113. Recommendation?
Explicit merges into the mainline
4
Don’t fear the Merge! Use it!
git log --first-parent
5
May rebase feature branches

114. Recommendation?
Explicit merges into the mainline
4
Don’t fear the Merge! Use it!
git log --first-parent
5
May rebase feature branches
To update the feature branch

115. Recommendation?
Explicit merges into the mainline
4
Don’t fear the Merge! Use it!
git log --first-parent
After review!
5
May rebase feature branches
To update the feature branch

116. Recommendation?
Explicit merges into the mainline
4
Don’t fear the Merge! Use it!
git log --first-parent
After review!
5
May rebase feature branches
To update the feature branch
6
Work with the tool!

117. Recommendation?
Explicit merges into the mainline
4
Don’t fear the Merge! Use it!
git log --first-parent
After review!
5
May rebase feature branches
To update the feature branch
6
Work with the tool!
Trying to strive for a linearized history is less useful than you think

118. Single Repository
vs
Remote Forks

119. With Forks
Every one has their
remote repository

120. With Forks
Every one has their
remote repository
Full remote copy,
each has one
Integrator, Gatekeeper,
Tech Lead, etc.

121. Pros of a Single Repo

122. Pros of a Single Repo
1
Complete visibility

123. Pros of a Single Repo
All feature
branches
available
1
Complete visibility

124. Pros of a Single Repo
All feature
branches
available
1
Complete visibility
2
No per Dev remotes required

125. Pros of a Single Repo
All feature
branches
available
1
Complete visibility
2
No per Dev remotes required
3
KISS

126. Forks
Are Great too BTW

127. FORKING
IN THE
ENTERPRISE

129. FORKING IN
5 Reasons for...
ENTERPRISE

130. FORKING IN
ENTERPRISE
REASON 1
Great for customizing libraries

131. FORKING IN
ENTERPRISE
REASON 1
Great for customizing libraries
and still get bug fixes

132. FORKING IN
ENTERPRISE
REASON 2
Great for innovation spikes

133. FORKING IN
ENTERPRISE
REASON 2
Great for innovation spikes
and maybe add it later

134. FORKING IN
ENTERPRISE
REASON 3
Protecting your components

135. FORKING IN
but still be open for changes
REASON 3
Protecting your components
ENTERPRISE

136. FORKING IN
ENTERPRISE
REASON 4
Reduce the noise

137. FORKING IN
ENTERPRISE
REASON 4
Reduce the noise
and keep the overview for huge projects

138. FORKING IN
ENTERPRISE
REASON 5
Interaction with Contractors &
Interns

139. FORKING IN
ENTERPRISE
REASON 5
Interaction with Contractors &
Interns
protect your sources

140. Tooling & Automation

141. 3
Tooling & Automation

142. Hooks

143. “
Hooks are little scripts you can place in
the `$GIT_DIR/hooks` directory to trigger
”
action at certain points.
– githooks Documentation

144. Pre
Post

145. Local
Remote

146. Local
pre-/post-applypatch
pre-/post-commit
Remote
pre-receive
update
pre-rebase
post-receive
post-checkout
post-update
post-merge
pre-push

147. Code Quality
via pre-commit hooks

148. .git/hooks/pre-commit

149. git add -u
git commit -m "TEST checkstyle"

150. Starting audit...
/Users/user/[...]/com/atlassian/stash/
web/projects/ProjectController.java:
161:12: 'for' is not followed by
whitespace.
Audit done.
Commit aborted.

151. Branch from green builds

152. .git/hooks/post-checkout

153. $ git checkout master
master is lookin'good!
c4f3b4b has 4 green builds.
$ git checkout stable-2.3
DANGER! stable-2.3 is
busted. e1324fa has 2 red
builds.

154. Get it at:
bitly.com/green-builds

155. What happens to CI with
?

156. 4
What happens to CI with
?

158. 1
What happens to CI with git?

159. 1
What happens to CI with git?
2
An explosion of branches

160. 1
What happens to CI with git?
2
An explosion of branches
3
Performance degradation of build sys

162. 1
Building everything is expensive

163. 1
Building everything is expensive
2
Automatically build stable and master

164. 1
Building everything is expensive
2
Automatically build stable and master
3
Manually trigger feature branch builds

165. In Conclusion: the recipe

166. Conclusions
Collaboration
Model
Branching
Model
Practices &
Decisions
Automation &
CI setup

167. Conclusions
Collaboration
Model
Centralized
Branching
Model
Practices &
Decisions
Automation &
CI setup

168. Conclusions
Collaboration
Model
Branching
Model
Product
workflow
Centralized
Practices &
Decisions
Automation &
CI setup

169. Conclusions
Collaboration
Model
Branching
Model
Product
workflow
Centralized
Continuous
delivery
workflow
Practices &
Decisions
Automation &
CI setup

170. Conclusions
Collaboration
Model
Branching
Model
Product
workflow
Centralized
Continuous
delivery
workflow
Practices &
Decisions
Embrace PR
Automation &
CI setup

171. Conclusions
Collaboration
Model
Branching
Model
Product
workflow
Practices &
Decisions
Embrace PR
Merge vs
Centralized
Continuous
delivery
workflow
Rebase
Automation &
CI setup

172. Conclusions
Collaboration
Model
Branching
Model
Product
workflow
Practices &
Decisions
Embrace PR
Merge vs
Centralized
Continuous
Rebase
delivery
workflow
Single Repo
or Forks
Automation &
CI setup

173. Conclusions
Collaboration
Model
Branching
Model
Product
workflow
Practices &
Decisions
Embrace PR
Merge vs
Centralized
Continuous
Rebase
delivery
workflow
Single Repo
or Forks
Automation &
CI setup
Hooks, hooks
everywhere

174. Conclusions
Collaboration
Model
Branching
Model
Product
workflow
Practices &
Decisions
Embrace PR
Merge vs
Centralized
Continuous
Rebase
delivery
workflow
Single Repo
or Forks
Automation &
CI setup
Hooks, hooks
everywhere
Build
automatically,
but leave
knobs!

175. Nicola Paolucci
THANK YOU FOR YOUR ATTENTION!
Should I change the pic? ;-)
durdn.com
@durdn

176. Atlassian
Git Repository Management
for Enterprise Teams
Free Git Code Hosting
for Small Teams
Free Git Desktop client
for Mac or Windows