harshadjoshi619/jenkins-pipeline

Automated CI/CD using Docker and Jenkins

This repository is a tutorial it tries to exemplify how to automatically manage the process of building, testing with the highest coverage, and deployment phases.

Our goal is to ensure our pipeline works well after each code being pushed. The processes we want to auto-manage:

• Code checkout
• Run tests
• Compile the code
• Run Sonarqube analysis on the code
• Create Docker image
• Push the image to Docker Hub
• Pull and run the image

First step, running up the services

Since one of the goals is to obtain the sonarqube report of our project, we should be able to access sonarqube from the jenkins service. Docker compose is a best choice to run services working together. We configure our application services in a yaml file as below.

docker-compose.yml

version: '3.2'
services:
  sonarqube:
    build:
      context: sonarqube/
    ports:
      - 9000:9000
      - 9092:9092
    container_name: sonarqube
  jenkins:
    build:
      context: jenkins/
    privileged: true
    user: root
    ports:
      - 8080:8080
      - 50000:50000
    container_name: jenkins
    volumes:
      - /tmp/jenkins:/var/jenkins_home #Remember that, the tmp directory is designed to be wiped on system reboot.
      - /var/run/docker.sock:/var/run/docker.sock
    depends_on:
      - sonarqube

Paths of docker files of the containers are specified at context attribute in the docker-compose file. Content of these files as follows.

sonarqube/Dockerfile

FROM sonarqube:6.7-alpine

jenkins/Dockerfile

FROM jenkins

If we run the following command in the same directory as the docker-compose.yml file, the Sonarqube and Jenkins containers will up and run.

docker-compose -f docker-compose.yml up --build

docker ps

CONTAINER ID        IMAGE                COMMAND                  CREATED              STATUS              PORTS                                              NAMES
ca8f0b63469f       pipeline_jenkins     "/bin/tini -- /usr..."   About a minute ago   Up About a minute   0.0.0.0:8080->8080/tcp, 0.0.0.0:50000->50000/tcp   jenkins
f5bed5ba3266        pipeline_sonarqube   "./bin/run.sh"           About a minute ago   Up About a minute   0.0.0.0:9000->9000/tcp, 0.0.0.0:9092->9092/tcp     sonarqube

## Jenkins configuration

We have configured Jenkins in the docker compose file to run on port 8080 therefore if we visit http://localhost:8080 we will be greeted with a screen like this.

![](images/004.png)

We need the admin password to proceed to installation. It’s stored in the ``/var/jenkins_home/secrets/initialAdminPassword`` directory and also It’s written as output on the console when Jenkins starts.

jenkins | ************************************************************* jenkins | jenkins | Jenkins initial setup is required. An admin user has been created and a password generated. jenkins | Please use the following password to proceed to installation: jenkins | jenkins | 45638c79cecd4f43962da2933980197e jenkins | jenkins | This may also be found at: /var/jenkins_home/secrets/initialAdminPassword jenkins | jenkins | *************************************************************

To access the password from the container.

docker exec -it jenkins sh / $ cat /var/jenkins_home/secrets/initialAdminPassword

After entering the password, we will download recommended plugins and define an ``admin user``.

![](images/)

![](images/)

![](images/007.png)

After clicking **Save and Finish** and **Start using Jenkins** buttons, we should be seeing the Jenkins homepage. One of the seven goals listed above is that we must have the ability to build an image in the Jenkins being dockerized. Take a look at the volume definitions of the Jenkins service in the compose file.

• /var/run/docker.sock:/var/run/docker.sock

The purpose is to communicate between the ``Docker Daemon`` and the ``Docker Client``(_we will install it on Jenkins_) over the socket. Like the docker client, we also need ``Maven`` to compile the application. For the installation of these tools, we need to perform the ``Maven`` and ``Docker Client`` configurations under _Manage Jenkins -> Global Tool Configuration_ menu.

![](images/008.png)

We have added the ``Maven and Docker installers`` and have checked the ``Install automatically`` checkbox. These tools are installed by Jenkins when our script([Jenkins file](https://github.com/vineet68sharma/CI-CD-Docker/blob/master/Jenkinsfile)) first runs. We give ``myMaven`` and ``myDocker`` names to the tools. We will access these tools with this names in the script file.

Since we will perform some operations such as ``checkout codebase`` and ``pushing an image to Docker Hub``, we need to define the ``Docker Hub Credentials``. Keep in mind that if we are using a **private repo**, we must define ``Github credentials``. These definitions are performed under _Jenkins Home Page -> Credentials -> Global credentials (unrestricted) -> Add Credentials_ menu.

![](images/009.png)

We use the value we entered in the ``ID`` field to Docker Login in the script file. Now, we define pipeline under _Jenkins Home Page -> New Item_ menu.

![](images/015.png)

Also Dont forget to mark env variables for Docker username and Docker password .

![](images/010.png)

In this step, we select ``GitHub hook trigger for GITScm pooling`` options for automatic run of the pipeline by ``Github hook`` call.

![](images/011.png)

Also in the Pipeline section, we select the ``Pipeline script from SCM`` as Definition, define the GitHub repository and the branch name, and specify the script location (_[https://github.com/prakashk0301/CI-CD-Docker/blob/master/Jenkinsfile)_).

![](images/012.png)

Create a repository in docker hub so the built image is pushed to docker registry with its credentials (need to be filled in jenkinsFile)
 
![]()


After that, when a push is done to the remote repository or when you manually trigger the pipeline by ``Build Now`` option, the steps described in Jenkins file will be executed.

![](images/013.png)

After that, when a Deployment  is done to the remote repository or when you manually trigger the pipeline by ``Build Now`` You can see the Workflow step by step .

![](images/014.png)


After Deployment is done and Container is running , You can check it by URL and Port number on which the service is running

 http://ec2-50-16-10-93.compute-1.amazonaws.com:8090/

![](images/017.png)


## Review important points of the Jenkins file

stage('Initialize'){ def dockerHome = tool 'myDocker' def mavenHome = tool 'myMaven' env.PATH = "${dockerHome}/bin:${mavenHome}/bin:${env.PATH}" }

The ``Maven`` and ``Docker client`` tools we have defined in Jenkins under _Global Tool Configuration_ menu are added to the ``PATH environment variable`` for using these tools with ``sh command``.

stage('Push to Docker Registry'){ withCredentials([usernamePassword(credentialsId: 'dockerHubAccount', usernameVariable: 'USERNAME', passwordVariable: 'PASSWORD')]) { pushToImage(CONTAINER_NAME, CONTAINER_TAG, USERNAME, PASSWORD) } }

``withCredentials`` provided by ``Jenkins Credentials Binding Plugin`` and bind credentials to variables. We passed **dockerHubAccount** value with ``credentialsId`` parameter. Remember that, dockerHubAccount value is Docker Hub credentials ID we have defined it under _Jenkins Home Page -> Credentials -> Global credentials (unrestricted) -> Add Credentials_ menu. In this way, we access to the username and password information of the account for login.

## Sonarqube configuration

For ``Sonarqube`` we have made the following definitions in the ``pom.xml`` file of the project.

```xml
<sonar.host.url>http://sonarqube:9000</sonar.host.url>
...
<dependencies>
...
    <dependency>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>sonar-maven-plugin</artifactId>
        <version>2.7.1</version>
        <type>maven-plugin</type>
    </dependency>
...
</dependencies>

In the docker compose file, we gave the name of the Sonarqube service which is sonarqube, this is why in the pom.xml file, the sonar URL was defined as http://sonarqube:9000.