This document provides an overview of continuous integration/continuous delivery (CI/CD) using open source tools Git, Gerrit, and Jenkins. It discusses the key principles of DevOps, continuous delivery and continuous deployment. It then describes how Git is used for version control, Gerrit for code reviews, and Jenkins for continuous integration. The rest of the document demonstrates setting up these tools, configuring Jenkins plugins, and walking through the workflow of making a code change in Git, pushing to Gerrit for review, and triggering an automated build in Jenkins.

1. 2015
CI/CD Overview
Lakshmi Easuwaran
3-Dec-2015
#GHCI15
2015

2. 2015
Agenda
 What is DevOps, continuous delivery and
continuous deployment
 Key underlying Principles
 Various tools & technologies in various phases
 Case study
 Books to read

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6. 2015
BUILD
IN

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Various tools & technologies

11. 2015
Case Study
 Test strategy (Agile test pyramid)
 How long does compilation take?
 Dev productivity tools
 Automated Infrastructure
 SMS/text messaging notifications

12. 2015
Case study - Agile test pyramid
Back

13. 2015
Books to read
 Continuous delivery by Jezz Humble and David
Farley
 The phoenix project by Gene Kim, Kevin Behr,
George Spafford

14. 2015
Open Source Solution
for
Continuous Delivery-
Git Gerrit and Jenkins
Mythri P K
3-Dec-2015
#GHCI15
2015

15. 2015
GIT – Why Version Control?
 Allows developers to work simultaneously
 No overwriting
 History is maintained

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GIT - WHAT
 Developed by Linus Torvalds in 2005
 It is under GPL License.
 It is a revision control system focused on speed
and efficiency
 Core is written in C.
 Compress and stores data hence memory foot
print is low
 Distributed version control system - avoids single
point failure

17. 2015
GIT - Workflow

18. 2015
GERRIT – WHY CODE REVIEW ?
 Early error detection
 Conformation to the source code standards
 Helps to keep code readable and easier to
maintain
 Knowledge exchange
 Shared code ownership

19. 2015
GERRIT- WHAT
 Gerrit is a web based code review system
 Gerrit is a Git server
 Gerrit fine grained access control system
through ssh
 Gerrit is licensed under the Apache 2.0
license.
 Gerrit is based on Google Web Toolkit

20. 2015
GERRIT - WORKFLOW
 Push the change to the Gerrit review system
to create a change for the master branch.
 On Improvement fetch the latest changes and
rebase patch.
Working
Tree
Local
Repository
Remote
Repository
Pull/fetch
Gerrit
Server
Push for review
Local Machine
On successful
Build and Review

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JENKINS – WHAT ?
 Jenkins is a cross-platform, continuous
integration and continuous
delivery application
 It is a server based system build and test tool.
 Released under the MIT License

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JENKINS – WHY ?
 Build problems are detected immediately by
automatic test builds.
 Checks for compile time errors and runs a test
suite.

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CONTINOUS INTEGRATION – HOW
?
Working
Tree
Local Repository
Remote
Repository
Pull/fetch
Gerrit
Server
Push for review
Local Machine
On successful
Build and Review
Jenkins
CI
Auto Build on Submission
Verified on successful build

24. 2015
Git- Workflow
Mythri P K
3-Dec-2015
#GHCI15
2015

25. 2015
Git- Glossary
 Tree: Directory with files (blobs) and
subdirectories (trees)
 Clone: Copy remote repository to local directory
 Head: Currently checked out commit
 Branch: Label given to commit for different line of
development
 Master: Main Branch
 Patch: Commit exported into text format

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Git

27. 2015
Git – Push, Pull & Fetch
 Git clone (Clone a repository
into a new directory)
 git fetch (Download objects
and refs from another
repository)
 git pull(Fetch from and
integrate with another
repository or a local branch)
 git push (Update remote refs
along with associated objects)

28. 2015
Git - Branches
 git checkout (To Switch
branches or restore
working tree files)
• –b <branch name>
 git –D <branch name >
(To Delete a branch)
 git branch –a (To List all
branches)

29. 2015
Git- Commits
 git log (show commit logs)
− git log –oneline
− git log –author = “name”
− git log --oneline --date-order -
-graph --all –decorate
 git whatchanged --since= "2
weeks ago“ (Show logs with
difference each commit
introduces)
 git-grep (Print lines matching a
pattern)

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Git- Add & commit
 git add <filename> (Add file
contents to the index)
 git commit (Record changes
to the repository)
− git commit –amend
 git rebase (To rearrange
series)
− -i (Interactive)
 git format-patch (To make
change as patch)

31. 2015
Git- Diff, Status & Reset
 git diff (changes between
two commits/ commit &
working Tree)
− git diff –cached.
− git diff –stat
 git status –a (working tree
status)
 git reset ( Reset current
HEAD to the specified state)
− –soft filename
− –hard

32. 2015
Git – Additional commands
 git stash
− git stash pop (To go back to the stashed state, works
like a stack)
− git stash list
 git merge-tool
 Git revert ( Revert a commit)
 Git tag ( To tag a significant commit)
 git-bisect
− Git-bisect visualize

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References
 http://gitref.org/
 https://git-scm.com/docs/git-checkout

34. 2015
Open Source Solution
for
Continuous Delivery
Git Gerrit and Jenkins
DEMO
Vinaya
3 Dec 2015
#GHCI15
2015

35. 2015
Github & Gerrithub setup
 Create Github account
https://github.com/
 Login to gerrithub.io using same github account
http://gerrithub.io/
 Open the git bash or Linux terminal
sudo su <username>
cd /home/<username>
 Generate ssh key using following command:
ssh-keygen –t rsa –b 4096 –C <user email id>
This creates id_rsa.pub file in ~/.ssh directory
 Copy id_rsa.pub content and paste it in “Add SSH Public Key” in the gerrithub link
https://review.gerrithub.io/#/settings/ssh-keys

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Github & Gerrithub setup

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Github & Gerrithub setup
 Git comes with a tool called git config that lets you get and set configuration variables that
control all aspects of how Git looks and operates
 Set identity
− git config --global user.name “Full Name”
− git config --global user.email mailid
 Checking Your Settings
− git config --list
 Checking value of a config key
− git config <key>
− Eg. git config user.name

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Jenkins Setup
 Jenkins installation link:
https://wiki.jenkins-ci.org/display/JENKINS/Installing+Jenkins
Jenkins server used for demo & workshop: 10.197.24.59:8081

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Jenkins plugins
 Install required Jenkins plugins
using “Manage Plugins” and
configure Jenkins server using
“Configure System”
 Following Jenkins Plugins
required for git and gerrit :
GIT plugin
Hudson Gerrit plugin
Gerrit trigger plugin
Build Environment
GitHub Pull Request Builder
Delivery Pipeline Plugin

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Jenkins Configuration
 Following settings required in Jenkins configure system:
 Path to Git executable: Mention the path to GIT executable.
 Update Jenkins URL as below:

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Jenkins Configuration
 Set up GitHub Pull Request Builder:
 Configuration of credentials
Username: Github username
Password: gerrithub http password (https://review.gerrithub.io/#/settings/http-password)
ID: Same as username

42. 2015
Configuration of gerrit trigger
 Manage Jenkins Gerrit Trigger:
 Select “Add New Server” and configure the gerrit server as below:
Note: SSH Keyfile Password should be left blank. It is generated automatically
when pressed “Test connection”. The Test connection should be successful.

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Jenkins new job configuration
 Open Jenkins URL
 Configure Source Code Management for created new job as follows:

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Jenkins new job configuration
 Configure Build Triggers as follows:

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Jenkins new job configuration
 Configure Build as follows:
 Select “Execute Shell” option from drop down and mention the build commands.
 Save the configuration by selecting “Save” option at the bottom.

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GIT, GERRIT, JENKINS flow
 Log in to gerrithub http://gerrithub.io/
 Filter the project “VinayaNP/ghci_ws_1” and select the same.
 Clone the project by copying the command highlighted below.

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GIT, GERRIT, JENKINS flow
 Open the Linux terminal.
 Create directory for the project.
 mkdir workshop
 cd workshop
 Clone the project VinayaNP/ghci_ws_1 by using command copied from gerrithub.
 The ghci_ws_1 project will be available in your directory.
 Edit the file from sample directory:

48. 2015
GIT, GERRIT, JENKINS flow
 Check git status:
 Give following commands to push the changes to gerrithub for review & verification:
git add <filename>
git commit –m <commit message>
git pull
Resolve the conflicts if you get any merge conflict.
git push origin HEAD:refs/for/master

49. 2015
GIT, GERRIT, JENKINS flow
 Give the http password from gerrithub settings:
https://review.gerrithub.io/#/settings/http-password
 The Jenkins job (e.g. Java_junit) will get triggered.

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GIT, GERRIT, JENKINS flow
 Once the build is complete, the status of the build is updated as blue (successful build) or red
ball (Failed build). The test result graph is also displayed.

51. 2015
GIT, GERRIT, JENKINS flow
 Go to gerrithub and check status of project:
If the build is successful, verification will get +1.
If the build is Fails, verification will get -1.
Further when Reviewer gives “Code-Review+2”, the changes can be submitted to github.

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Delivery Pipeline

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Thank You!

54. 2015
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