The document outlines various Git workflows, including centralized, feature branch, Gitflow, and forking workflows. Each workflow is described in terms of its typical sequence, advantages, and ramifications, catering to different team sizes and project complexities. The importance of pull requests and their role in facilitating discussions and code reviews is also highlighted.

1. Git Workflows
Noam Kfir | Sela Group | 2014

2. Workflows
 Centralized
 Feature Branch
 Gitflow
 Forking
 Pull Requests
Adapted from Atlassian, experience and other sources

3. Centralized – Overview
 Centralized by convention
 One shared branch  master
 Central history is never rewritten!
 Central repository is usually bare
 Emulates a central VCS like TFS or Subversion
 Local master tracks remote master
 Local rebase often preferable to merge
 Local repository is never bare

4. The Centralized Workflow
master

5. Centralized – Typical Sequence
 git clone remote // copy the central repository to a local repository
 // iterative edit/stage/commit process
 git pull [--rebase] origin master // merge or rebase the latest central version
 git push [origin master] // share your work with the central repository

6. Centralized – Ramifications
 Suitable for small teams
 Supports multiple atomic commits before sharing with the team
 Risk losing local history if changes are not pushed often enough
 Larger teams working on more concurrent features are more difficult to manage
 Higher chance of merge conflicts
 Harder to keep the central master history linear
 Has limited support for communication

7. The Feature Branch Workflow
master
foo
bar

8. Feature Branch – Overview
 Dedicated feature branches
 Often combined with Centralized
Workflow
 Feature branches are pushed to the
central repository
 Devs never work on the master branch
 Individual features built on dedicated
feature branches
 Backup for feature branches too
 Multiple devs work on the same feature

9. Feature Branch – Typical Sequence
 git clone remote // copy the central repository to a local repository
 git checkout -b new-feature // create a new local feature branch
 // iterative edit/stage/commit process
 git push [-u origin new-feature] // share the branch [and track it]

10. Feature Branch – Merge Into master
 git checkout master
 git pull [--rebase] origin new-feature // merge [or rebase] the latest central version
 git push origin master // send the final version to the central master

11. Feature Branch – Ramifications
 Suitable for larger teams working on multiple concurrent features
 The central repository contains both master and feature branches
 The master branch is easier to control and safeguard
 Very flexible workflow but relies on responsible programmers
 Supports:
 pull requests
 isolated experiments
 efficient collaboration

12. The Gitflow Workflow
image source: https://www.atlassian.com/git/workflows#!workflow-gitflow

13. Gitflow – Overview
 Focused on project release cycle
 Similar to the Feature Branch Workflow
 Uses a strict branching model
 Uses a central repository
• Feature branches
• Individual branches
 Each branch has a specific role
 Strict rules on when branches can interact

14. Gitflow - Branches
master
hotfix
release
develop
feature
• official releases, tagged
• patches, bug fixes [ master]
• release targets [ master]
• feature integration branch [ release]
• dedicated feature branches [ develop]

15. Gitflow – The master Branch
 The central authority
 Sacred
 Every commit represents a version
 Every commit has a version tag
 Branch from master: only hotfix and develop
 Push to master: only hotfix and release

16. Gitflow – Hotfixes
 Hotfixes are meant for critical maintenance issues only
 Based on master, pushed to master
 Usually numbered as a minor version
 Sidestep the normal development workflow  discouraged!
Numbered
hotfix
branched
from master
Merged
back into
master
master
tagged with
version tag
hotfix
merged
into
develop
hotfix
deleted

17. Gitflow – Features
 There is only one develop branch, based on master
 Every feature has its own feature branch
 feature branches based on develop, pushed to develop
 feature branches named for the features
Named
feature
branched
from
develop
feature
shared with
team
Concurrent
local work
on feature
feature
merged
back into
develop
when ready
feature
(optionally)
deleted

18. Gitflow – Releases
 There is only one develop branch, based on master
 Every release has its own release branch, based on develop
 release named with version number (usually either major or minor)
 release branches are merged into master and develop when releases are ready
Numbered
release
branched
from
develop
Bug fixes,
docs,
preparation
on release
release
merged into
master
when ready
to ship
master
tagged with
version tag
release
merged
back into
develop
release
deleted

19. Gitflow – Ramifications
 Intended for large projects
 Feature teams can continue working while the current release is being prepared
 Same advantages as Feature Branch Workflow:
 pull requests
 isolated experiments
 efficient collaboration
 Branch structure mirrors release process:
 visually identifiable
 easy to communicate

20. The Forking Workflow
foo
master
foo
master
bar
master

21. The Forking Workflow
 A distributed workflow
 Every dev forks the official repository
 Official maintainer has ultimate control,
but only by agreement
 Unrelated to the Centralized Workflow
 Forks are private server copies
 No shared centralized repositories
 Central authority is arbitrary
and determined by policy or consensus

22. Forking – Branches
 Multiple repositories:
 “Official” public server repository
 Forked server repositories
 Cloned local repositories
 Forking is different from cloning – forking creates a bare server copy, cloning creates a full local copy
 Each developer has exclusive write access only to their own repositories
 To integrate back into the official repository, developers push to theirs and then issue a pull request
 Local clones of forked repositories usually define two remotes:
 origin – points to the forked repository
 upstream – points to the official public repository

23. Forking – Ramifications
 Designed for large organic teams, including open source projects and distributed teams
 Every dev can do their own private Feature Branch workflow with their own server
 Official maintainer is very common in open source projects
 Companies give write access to official repository/branch to responsible “maintainer”
 Extremely effective with pull requests

24. Understanding Pull Requests
 Safety net
 Distributed communication mechanism
 Effective code review platform
 Not actually part of git!
 When a feature is complete, it is not merged into master
 The feature developer issues a pull request to the maintainer of the master branch
 The maintainer reviews the changes and then merges them or rejects them
 The pull request is a forum for discussion about the feature
 Pull requests facilitate better communication and code reviews

25. The Pull Request Workflow
Feature is
finished in
private
branch
Dev issues
pull request
to source
repo
Maintainer
reviews
changes
Maintainer
and dev
discuss the
feature
Maintainer
merges or
rejects
request

26. Summary
 Git is a very rich distributed version control system
 Its design supports many different types of workflows,
including centralized and distributed workflows
and is suitable for:
 individual programmers
 small co-located teams
 massive distributed teams
 anything from open source projects to corporations
 Its workflows have evolved over the years to popular, mature and proven guidelines

27. Thank You!