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Git and branching modelsby Pavlo Hodysh

Working with source codeWhat we do:- Copy & paste files &

folders- Carry code on

external drives- Backup using manual

copies

Problems:- Forget to make a

copy- Hard to manage

copies- Hard to share

versions between collaborators

- Hard to share access- No descriptive history

Working with source codeWhat I want:- Automatically backup- Keep history of

changes- Easily share code- Easily share access- Collaborate in teams

Solution:- Use a VCS already!

What is version control?A component of software configuration management, version control (revision control, source control), is the management of changes to documents, computer programs, large web sites, and other collections of information (from Wikipedia)

What problems does it solve?Pros.- Work in teams- Automatic backup - Revision history- Automatic builds on

CI

Cons.- You need to learn it- You need to install it

… yeah, like it’s hard

Version Control SystemsGeneration 0 - The stone age (Ctrl + C -> Ctrl + V)Generation 1 - Local (RCS, SCCS)Generation 2 - Centralized (CVS, Subversion, Team Foundation)Generation 3 - Distributed (Git, Mercurial)

Basic conceptsRepository:- Place where you store your source code- Contains every revision of your code- Shares access to source code for your team- Serves as a backup for yahoo source code

REPOSITORY

Basic concepts

Working copy:- Snapshot of your last commit- Place where changes are added- Local, visible only by you- Contains metadata about state of things

- Files added- Files modified- Files renamed- Files deleted

WORKING COPY

Basic concepts

Commit:- Moves working copy to a repository- Has a description message- Has a revision number

REPOSITORY

WORKING COPY

COMMIT

Basic concepts

Update:- Updates the working copy from a repository- Merges changes with working copy

REPOSITORY

WORKING COPY

UPDATE

Centralized Version Control- Remote repository- Multiple clients, one server

REPOSITORY

WORKING COPY

WORKING COPY

WORKING COPY

Distributed Version Control- Multiple clients with multiple local repositories- One centralized server

REPOSITORY

WORKING COPY

WORKING COPY

WORKING COPY

Centralized vs. Distributed

Basic concepts

Pull:- Updates the local repository from a remote

repository- Merges changes with working copy on local

repository

LOCAL REMOTE

PULL

Basic concepts

Push:- Moves changes from local repository to remote- Moves all history from last push

LOCAL REMOTE

PUSH

Getting started with GitStandard installations- http://git-scm.com/downloads

Available for all the platform

Git Graphical Applications- http://git-scm.com/downloads/guis- https://www.sourcetreeapp.com/- https://www.gitkraken.com/

GitFlow branching modelKey Benefits- Stable versions ready for production via master branch

- Staging area via develop branch

- Collaboration via feature branches

- Releases area via release branches

- Support for emergency fixes via hotfix branch

How it works?- We start with master branch

- Create develop branch from master

- Create feature branches from develop

How it works?- We develop our features in

separate feature branches

- When the feature is finished we merge it back into develop

How it works?- When it is time to make a

release, create a release branch from develop

- Code in the release branch is deployed, tested, and any bugs are fixed directly in the release branch

- When finished, the release branch is merged into master and into develop, so that all bug fixes are not lost

How it works?- In case of bugs on production

we create hotfix branch from master

- When finished, merge back into both master and develop to make sure that the hotfix isn’t accidentally lost

Merge vs. Rebase- Merging brings two lines of

development together while preserving the ancestry of each commit history.

- Rebasing unifies the lines of development by rewriting changes from the source branch so that they appear as children of the destination branch

Golden rule of rebasing

NEVER EVERrebase a branch that you pushed,

or that you pulled from another person

Pull requests- Create a pull requests

from feature branch

- Let the peer review and comment the code

- When the pull request is approved feature branch is merged

Useful linksGitFlow by Vincent Driessenhttp://nvie.com/posts/a-successful-git-branching-model/

GitFlow Cheatsheethttp://danielkummer.github.io/git-flow-cheatsheet/

Git workflow by Atlassianhttps://www.atlassian.com/git/tutorials/comparing-workflows/feature-branch-workflow

GitFlow step-by-stephttps://datasift.github.io/gitflow/IntroducingGitFlow.html

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