Git Tutorial

Git Tutorial

by John Vincent


Posted on January 22, 2017


Git is a distributed version control system (DVCS), also known as decentralized. This means that every developer has a full copy of the repository, which is hosted in the cloud.

Git Options

Git Tools

Fork and SourceTree are excellent tools. I regularly use them as I prefer a UI app to the command line.

However, it is probably best to first learn how git works before relying on these tools.

Git Global

Create file /Users/jv/Desktop/MyDevelopment/github/repo_shell_scripts/mac/git/config

#!/bin/sh
#
#  script to configure git
#
echo "Script to configure git"
#
NAME=your-github-id
EMAIL=your-github-email
IGNORE_GLOBAL=/Users/jv/Desktop/MyDevelopment/github/repo_shell_scripts/mac/git/.gitignore_global
#
git config --global user.name $NAME
git config --global user.email $EMAIL
git config --global core.excludesfile $IGNORE_GLOBAL
#
# git merge
#
git config merge.tool vimdiff
git config merge.conflictstyle diff3
git config mergetool.prompt false
#
# aliases
#
git config --global alias.hist1 "log --graph --date-order -C -M --pretty=format:'<%h> %ad [%an] %Cgreen%d%Creset %s' --all --date=short"
git config --global alias.hist2 "log --pretty=format:'%h %ad | %s%d [%an]' --graph --date=short"
git config --global alias.hist3 "git log --all --decorate --oneline --graph"
#
echo "Show configuration"
#
git config --list

To show the various branches and their interactions

git hist1

Note git config merge.tool opendiff is also very effective.

IGNORE_GLOBAL is used to enable Git to mark this file as a global .gitignore. It will subsequently be used to mark files to ignore in case no local .gitignore is found

Create git global file /Users/jv/Desktop/MyDevelopment/github/repo_shell_scripts/mac/.gitignore_global

*~
.DS_Store
.*.swp
.*.swo
*.sass-cache
node_modules/
*.*.bak
.metadata/
RemoteSystemsTempFiles/
Pivotal tc Server Developer Edition v3.1-config/

Also may need to add

*.class
bin/

Set your environment

. /Users/jv/Desktop/MyDevelopment/github/repo_shell_scripts/mac/git/config

Show Git Global

Show system, global, and (if inside a repository) local configs.

git config --list

Create a Repository I

From Github, Add repository git-tutorial

echo "# git-tutorial" >> README.md
git init
git add README.md
git commit -m "first commit"
git remote add origin git@github.com:johnvincentio/git-tutorial.git
git push -u origin master

Create a Repository II

The following is my process.

  • Create public or private repository at Github
  • cd {my-github-developer-folder}/{subdir}
  • create-repo remote-repository-name

This will quickly provide a development environment.

create-repo follows

#!/bin/sh
#
# script to create a git repository in github
#
echo "Script to create a git repository in github"
echo " "
echo "ENSURE YOU HAVE ALREADY CREATED the REPOSITORY in Github"
echo ""
NEW_REPO=$1
if [ -z "$NEW_REPO" ]; then
    echo "Usage: create-repo repository-name"
    exit 1
fi
#
echo "Creating local repository $NEW_REPO"
#
echo " "
echo "Checking if directory already exists"
if [ ! -d "$NEW_REPO" ]; then
    echo " "
     echo "Making directory $NEW_REPO"
     mkdir $NEW_REPO
    touch $NEW_REPO/index.html
#
    mkdir $NEW_REPO/css
    touch $NEW_REPO/css/main.css
#
    mkdir $NEW_REPO/js
    touch $NEW_REPO/js/app.js
fi
#
echo " "
echo "cd to $NEW_REPO"
cd $NEW_REPO
#
if [ ! -d ".git" ]; then
    echo " "
     echo "Create basic files"
     touch README.md
     touch .gitignore
    echo "node_modules" > .gitignore
#
    echo " "
    echo "Create local repository"
    git init
#
    echo " "
    echo "Adding files to repository and commit"
    git add *
    git add .gitignore
    git commit -m "Commit"
fi
#
echo " "
echo "Check status and branch info"
git status
git branch
#
echo " "
echo "Add remote repository reference"
git remote add origin git@github.com:{my-github}/$NEW_REPO.git
#
echo " "
echo "Push files to remote repository"
git push -u origin master
#
echo " "
echo "Verify remote repository"
git remote -v
#
echo " "
echo "Show git log"
git log
#
echo "Completed"

To create the repository

cd github/projects
create-repo git-tutorial

Create Project

From git-tutorial projects

Create Project

* Board Name: git-tutorial
* Template: Automated kanban

Git Branching Model

A successful Git branching model

This is a great starting point.

Git branching Model

Tutorial Guidelines

All tasks are a Jira ticket number. Thus the ticket number will always appear in the branch name.

Task Type Branch from New Branch Name
Single Task develop feature/{ticket-number}
User Story feature feature/{ticket-number}
Task in a User Story feature/{ticket-number} task/{ticket-number}
Development Testing Bug develop devfix/{ticket-number}
Release develop release/{release-number}
Post Integration Bug release/{release-number} bugfix/{ticket-number}
Emergency Release master hotfix/{ticket-number}

Main branches with an infinite timeline are

  • master
  • develop
  • release

origin/master - the main branch where the source code of HEAD always reflects a production-ready state.

origin/develop - the main branch where the source code of HEAD always reflects a state with the latest delivered development changes for the next release.

origin/release - the main branch where the source code of HEAD always reflects a release-ready state.

  • Each time develop is merged back into release, this is a new release candidate.
  • Each time release is merged back into master, this is a new production release.

Git Tutorial

The following is a demonstration of using Git in a project. To aid understanding

  • the only file in the project is README.md
  • commits to remote allow the change to be viewed from github

The steps will be:

  • Initialize master branch
  • Create develop branch from master
  • Create task branch feature/1001 from develop

    • Merge feature/1001 into the develop branch
  • Create a User Story

    • Create a User Story Branch feature/2000 from develop
    • Create Tasks branches from User Story Branch feature/2000
    • Merge task/2001 into the User Story Branch
    • Merge task/2002 into the User Story Branch
    • Merge task/2003 into the User Story Branch
  • Multiple Developers working on User Story branch feature/2000

    • Second developer makes a change to User Story branch feature/2000
    • Update Local Branch with changes from Remote Branch feature/2000
    • Merge the User Story Branch feature/2000 into the develop branch develop
  • Development Testing Bug, create branch devfix/9001 from develop

    • Merge devfix Branch devfix/9001 into develop branch
  • Create Release branch release/1.0 from develop
  • Post Integration Bug, create branch bugfix/9101 from release/1.0

    • Merge the bugfix branch bugfix/9101 into the release branch release/1.0
  • Release to Production, merge branch release/1.0 to master

    • Tag Release 1.0
  • Create Task Branch feature/1002 from develop

    • Merge branch feature/1002 into develop branch
  • Merge release branch release/1.0 into the develop branch
  • Fix an emergency bug in the production system

    • Merge branch hotfix/9201 into the master branch
    • Tag Release 1.0.1
    • Merge branch hotfix/9201 into the develop branch
  • Getting specific versions

The following is the SourceTree git graph of the git-tutorial repository after these tasks.

git-tutorial git graph

The following is the command line generated git graph of the git-tutorial repository after these tasks.

git-tutorial git graph

Initialize master branch

The repository has been created and I have master branch only.

cd github/projects/git-tutorial

Edit README.md, only initial master

git add .
git commit -m "initial"
git push

Create develop branch from master

git checkout -b develop
git push origin develop

Create task branch feature/1001 from develop

Edit Project git-tutorial, add tasks

  • 1001; Feature 1001

For ticket 1001, create branch feature/1001 from develop

git checkout -b feature/1001 develop

Edit README.md, only feature/1001 and commit.

git add .
git commit -m "feature/1001"
git push origin feature/1001

Merge feature/1001 into the develop branch

git checkout develop
git merge --no-ff feature/1001
git push origin develop

The --no-ff flag causes the merge to always create a new commit object, even if the merge could be performed with a fast-forward. This avoids losing information about the historical existence of a feature branch and groups together all commits that together added the feature. Reverting a whole feature (i.e. a group of commits) becomes straightforward.

use commit message

Task feature/1001 is complete

Optionally, clean up

git branch -d feature/1001

Create a User Story

Edit Project git-tutorial, add tasks

  • 2000; Feature 2000
  • 2001; Task A
  • 2002; Task B
  • 2003; Task C

Create a User Story Branch feature/2000 from develop

For ticket 2000, create branch feature/2000 from develop

git checkout -b feature/2000 develop

Edit README.md, ensure only

feature/1001

and change to

feature/1001
feature/2000

Commit

git add .
git commit -m "feature/2000"
git push origin feature/2000

Create Tasks branches from User Story Branch feature/2000

For ticket 2001, create branch task/2001 from feature/2000

git checkout -b task/2001 feature/2000

Edit README.md, ensure only

feature/1001
feature/2000

and change to

task/2001

and commit.

git add .
git commit -m "task/2001"
git push origin task/2001

Repeat the above for tickets 2002 and 2003

Merge task/2001 into the User Story Branch

git checkout feature/2000
git merge --no-ff task/2001

use commit message

task/2001 is complete

Handle the merge conflicts and then push to remote.

git push origin feature/2000

Merge task/2002 into the User Story Branch

Now handle task/2002

git merge --no-ff task/2002

get error

Auto-merging README.md
CONFLICT (content): Merge conflict in README.md
Automatic merge failed; fix conflicts and then commit the result.

Either fix the merge issues or abort the merge. Let's abort the merge.

git merge --abort
or
git reset --merge ORIG_HEAD

This time lets fix the merge conflict. git status will show files in confict.

Redo the merge

git merge --no-ff task/2002

Edit README.md ensure only

task/2001
task/2002

Now commit

git add README.md
git commit

use commit message

task/2002 is complete

and push to remote

git push origin feature/2000

Merge task/2003 into the User Story Branch

Now handle task/2003

git merge --no-ff task/2003

get error

Auto-merging README.md
CONFLICT (content): Merge conflict in README.md
Automatic merge failed; fix conflicts and then commit the result.

Lets fix the merge conflict. git status will show files in confict.

Edit README.md

task/2001
task/2002
task/2003

Now commit

git add README.md
git commit

using commit message

task/2003 is complete

and push to remote

git push origin feature/2000

Optionally, clean up

git branch -d task/2001
git branch -d task/2002
git branch -d task/2003

Multiple Developers working on User Story branch feature/2000

There are now multiple developers working on the project. The second developer makes a change to feature/2000

The first developer needs to get the change.

Second developer makes a change to User Story branch feature/2000

Copy feature/2000 branch to /tmp

git checkout feature/2000
cd ..
cp -R git-tutorial /tmp
cd /tmp/git-tutorial

Edit /tmp/git-tutorial/README.md, ensure only

task/2001
task/2002
task/2003

change to

task/2001
task/2002
task/2003
feature/2000

and commit

git add .
git commit -m "feature/2000"
git push origin feature/2000

Update Local Branch with changes from Remote Branch feature/2000

Edit github/projects/git-tutorial/README.md, ensure only

task/2001
task/2002
task/2003

Set tracking information for branch feature/2000

git checkout feature/2000
git branch -u origin/feature/2000
or
git branch --set-upstream-to origin/feature/2000

Perform the update

git pull

Verify README.md is

task/2001
task/2002
task/2003
feature/2000

Merge the User Story Branch feature/2000 into the develop branch develop

Now we have the completed User Story Branch feature/2000

git checkout develop
git merge --no-ff feature/2000

use commit message

User story feature/2000 is complete

Check README.md for branch develop in Github repository. Ensure only feature/1001

Push to remote

git push origin develop

ensure README.md is

task/2001 task/2002 task/2003 feature/2000

Clean up

git branch -a to list branches.

Optional, delete local branches

git branch -d task/2001
git branch -d task/2002
git branch -d task/2003

and delete remote branches

git push origin --delete task/2001
git push origin --delete task/2002
git push origin --delete task/2003

Development Testing Bug, create branch devfix/9001 from develop

Bug has been found during development testing.

Edit Project git-tutorial, add tasks

  • 9001; Bug 9001

Create branch devfix/9001 from develop

git checkout -b devfix/9001 develop

Edit README.md, ensure only

task/2001
task/2002
task/2003
feature/2000

Change to

task/2001
task/2002
task/2003
feature/2000
devfix/9001

and commit.

git add .
git commit -m "devfix/9001"
git push origin devfix/9001

Merge devfix Branch devfix/9001 into develop branch

Now the bug has been fixed, we need to merge back into develop

git checkout develop
git merge --no-ff devfix/9001

use commit message

Development bug 9001 is complete

Check README.md for branch develop in Github repository. Ensure only

task/2001
task/2002
task/2003
feature/2000

Push to remote

git push origin develop

ensure README.md is

task/2001
task/2002
task/2003
feature/2000
devfix/9001

Clean up

git branch -a to list branches.

Optional, delete local branches

git branch -d devfix/9001

and delete remote branches

git push origin --delete devfix/9001

Create Release branch release/1.0 from develop

Now the development work and testing are complete a release branch should be built.

Create branch release/1.0 from develop

git checkout -b release/1.0 develop

Edit README.md, ensure only

task/2001
task/2002
task/2003
feature/2000
devfix/9001

and change to

task/2001
task/2002
task/2003
feature/2000
devfix/9001
release/1.0

which mimics the updating of release meta-data.

Commit and push to remote

git commit -a -m "Release 1.0 meta-data"
git push origin release/1.0

Post Integration Bug, create branch bugfix/9101 from release/1.0

Bug has been found during post development testing (Qual testing).

Edit Project git-tutorial, add tasks

  • 9101; Bug 9101

Create branch bugfix/9101 from release/1.0

git checkout -b bugfix/9101 release/1.0

Edit README.md, ensure only

task/2001
task/2002
task/2003
feature/2000
devfix/9001
release/1.0

and change to

task/2001
task/2002
task/2003
feature/2000
devfix/9001
release/1.0
bugfix/9101

which mimics the the fixing of the bug.

Commit and push to remote

git commit -a -m "bugfix/9101"
git push origin bugfix/9101

Merge the bugfix Branch bugfix/9101 into the release branch release/1.0

Now the bug has been fixed, we need to merge back into release/1.0

git checkout release/1.0
git merge --no-ff bugfix/9101

use commit message

Qual bug 9101 is complete

Check README.md for branch release/1.0 in Github repository. Ensure only

task/2001
task/2002
task/2003
feature/2000
devfix/9001
release/1.0

Push to remote

git push origin release/1.0

ensure README.md is

task/2001
task/2002
task/2003
feature/2000
devfix/9001
release/1.0
bugfix/9101

Clean up

git branch -a to list branches.

Optional, delete local branches

git branch -d bugfix/9101

and delete remote branches

git push origin --delete bugfix/9101

Release to Production, merge branch release/1.0 to master

All development tasks and testing are complete. The release branch release/1.0 is ready to become a release.

git checkout master

Edit README.md, ensure only initial master

git merge --no-ff release/1.0

use commit message

Release 1.0 is complete

and then push to remote.

git push origin master

Check github repository, master branch README.md should be

task/2001
task/2002
task/2003
feature/2000
devfix/9001
release/1.0
bugfix/9101

Tag Release 1.0

git tag -a 1.0

use commit message

Release 1.0

and then push to remote.

git push --follow-tags
or
git push origin 1.0

To view the tag in Github repository git-tutorial

  • Select repository git-tutorial
  • click on branch to reveal tags tab.
  • select tag 1.0

README.md should be

task/2001
task/2002
task/2003
feature/2000
devfix/9001
release/1.0
bugfix/9101

Create Task Branch feature/1002 from develop

While the release 1.0 process was ongoing, the development process had continued.

Edit Project git-tutorial, add tasks

  • 1002; Feature 1002

For ticket 1002, create branch feature/1002 from develop

git checkout -b feature/1002 develop

Edit README.md, only

task/2001
task/2002
task/2003
feature/2000
devfix/9001

and change to

task/2001
task/2002
task/2003
feature/2000
devfix/9001
feature/1002

and commit.

git add .
git commit -m "feature/1002"
git push origin feature/1002

Merge branch feature/1002 into develop branch

git checkout develop
git merge --no-ff feature/1002

use commit message

feature/1002

and push to remote

git push origin develop

To view the branch in Github repository git-tutorial

  • Select repository git-tutorial
  • click on branch to reveal tags tab.
  • select branch develop

README.md should be

task/2001
task/2002
task/2003
feature/2000
devfix/9001
feature/1002

Clean up

git branch -a to list branches.

Optional, delete local branches

git branch -d feature/1002

and delete remote branches

git push origin --delete feature/1002

Merge release branch release/1.0 into the develop branch

The release branch release/1.0 now needs to be merged into develop. Notice that the develop branch already has changes for the future releases.

git checkout develop
git merge --no-ff release/1.0

which yields the error

Auto-merging README.md
CONFLICT (content): Merge conflict in README.md
Automatic merge failed; fix conflicts and then commit the result.

To list files in conflict

git status

which shows README.md

Edit README.md and resolve the conflicts by changing to

task/2001
task/2002
task/2003
feature/2000
devfix/9001
feature/1002
release/1.0
bugfix/9101
git add .
git commit -m "Merge Release 1.0 to develop"
git push origin develop

Check README.md for branch develop in Github repository. Ensure only

task/2001
task/2002
task/2003
feature/2000
devfix/9001
feature/1002
release/1.0
bugfix/9101

Clean up

git branch -a to list branches.

Optional, delete local branches

git branch -d release/1.0

and keep the remote branch.

Fix an emergency bug in the production system

Bug has been found in the production system.

Edit Project git-tutorial, add tasks

  • 9201; Bug 9201

Create branch hotfix/9201 from master

git checkout -b hotfix/9201 master

Edit README.md, ensure only

task/2001
task/2002
task/2003
feature/2000
devfix/9001
release/1.0
bugfix/9101

and change to

task/2001
task/2002
task/2003
feature/2000
devfix/9001
release/1.0
bugfix/9101
hotfix/9201

which mimics the the fixing of the bug.

Commit and push to remote

git commit -a -m "hotfix/9201"
git push origin hotfix/9201

Merge branch hotfix/9201 into the master branch

Now the bug has been fixed, we need to merge back into master

git checkout master
git merge --no-ff hotfix/9201

use commit message

hotfix/9201

and then push to remote.

git push origin master

Check github repository, master branch README.md should be

task/2001
task/2002
task/2003
feature/2000
devfix/9001
release/1.0
bugfix/9101
hotfix/9201

Tag Release 1.0.1

git tag -a 1.0.1

use commit message

Release 1.0.1

and then push to remote.

git push --follow-tags
or
git push origin 1.0.1

To view the tag in Github repository git-tutorial

  • Select repository git-tutorial
  • click on branch to reveal tags tab.
  • select tag 1.0.1

README.md should be

task/2001
task/2002
task/2003
feature/2000
devfix/9001
release/1.0
bugfix/9101
hotfix/9201

Merge branch hotfix/9201 into the develop branch

Now the bug has been fixed, we need to merge back into develop

git checkout develop
git merge --no-ff hotfix/9201

use commit message

hotfix/9201

and then push to remote.

git push origin develop

Check github repository, master branch README.md should be

task/2001
task/2002
task/2003
feature/2000
devfix/9001
feature/1002
release/1.0
bugfix/9101
hotfix/9201

Clean up

git branch -a to list branches.

Optional, delete local branches

git branch -d hotfix/9201

Getting specific versions

From history git hist1, find the hash for "Release 1.0"

Checkout the code

git checkout <hash>

and verify README.md is

task/2001
task/2002
task/2003
feature/2000
devfix/9001
release/1.0
bugfix/9101

Checkout another branch resets HEAD

git checkout develop
git status