🧛‍♂️ Jenkins Declarative Pipeline with - Docker,🐳 GitHub,🔀 Webhook🔗

Day 27 Task Of 90DaysOfDevOps Challenge

🎆Introduction

As of now, we are familiar with the Jenkins Declarative Pipeline Also, we are pretty familiar with Docker and Git, GitHub .

In this blog, we are deep dive into the Integration of Docker, GitHub , Webhook with Jenkins and we will take our skills to the next level.

🧛‍♂️🐳Create Jenkins Declarative Pipeline with - Docker and GitHub, Webhook🔗🔀

In this section, we are going to create a Jenkins Declarative Pipeline with Docker to host our application in a Docker container and GitHub to get the application code from the GitHub repository.

🔑Prerequisite

Make sure the following tools are installed and running in your system. Here we require the following tools...

🧛‍♂️Jenkins: To create the Jenkins Declarative Pipeline. Check out the link to install Jenkins. https://deepakcloud22.hashnode.dev/day-22-getting-started-with-jenkins

🐳Docker: Run the docker container to host our application. Check out the link to install docker https://deepakcloud22.hashnode.dev/day-16-task-docker-for-devops-engineers-part-1

🏢Docker Hub : To push the Docker image into the Docker Hub repository. Check out to create the Docker-Hub account https://docs.docker.com/docker-id/

🏢Git/GitHub Repo: To get the application code from the GitHub https://www.linkedin.com/pulse/day-8-task-basic-git-github-devops-engineers-deepak-patil/

📝Application Code: We will use the below application code you can clone the code or fork this repository https://github.com/Dips-1991/django-notes-app.git

⏭️Create The Pipeline

First, we will create the Pipeline. As we have installed Jenkins in our system.
Navigate to the Jenkins home page and click on New Item .
Enter name of the job.
Select the Pipeline as a project and click on Ok .
Enter the Description.
Select the GitHub project As we know we are integrating GitHub with Jenkins and adding the GitHub repo URL to the Project url As we know our application code is present on GitHub.

🔧Configure The Pipeline

Now, come to our main task here we will write the Ddeclerative pipeline Groovy syntax code.

🧬Clone Stage

Pipeline section: In the Definition select the Pipeline script from the drop-down.

🛠️Build Stage

Script section: Under stages in the first clone stage we are cloning the code. To clone the code we have to use the GitHub URL and the Branch Name where our code is present.
git url:"<github-repo-url>,<branch-name>"
In the second Build stage we are building the docker image using the Dockerfile. Here we have to use Groovy syntax to run the docker command with the help of sh.
sh "docker build -t Django-app-image ."

🚀Push Stage &Configuring The DockerHub Credentials

In the this stage, we are pushing the image to DockerHub. For that First, we will save our credentials in Jenkins and we are associate them with the ID.
As we are aware that exposing the credentials is how dangerous so, we are using here the Jenkins environment variable.
Navigate to the Manage jenkins --> Security --> Credentials
Click on the System under the Stores scoped to Jenkins
Once, you click on the System you will navigate to the next page where you have to click on Global credentials (unrestricted) .
Once you click you will navigate to the next page click on Add credentials.
Once, you click on Add credentials .You will navigate to the next page where we will store our DockerHub credentials.
Here in Kind select Username with password from the dropdown. As we are using DockerHub credentials.
Keep Scope as it is.
In the Username add the DockerHub Username .
In the Password add the DockerHub Password .
Keep Treat username as secret uncheck.
Enter the ID (credentials are associate with ID) name at your convenience. Then ID We will use in our code to fetch the username and password. Click on Create .
Now you will see the credentials are added.
In the Push Image stage We will push the image to DockerHub with the help of withCredentials function and will pass the credentiasId, usernameVariable, passwordVariable to the "usernamePassword" function.
1. withCredentials([usernamePassword(credentiasId:"<your-credentials ID>",usernameVariable:"<any-name>",passwordVariable:"<any-name>")])
2. In the next command, we have to tag our created image with the DockerHub username.
  
  sh "docker tag <image-name> $env.<usernameVariable>/<new-image-name:<tag>>"
3. In the next command, we will login to the DockerHub
  
  sh "docker login -u ${env.dockerUsername} -p ${env.dockerPassword}".
4. In the next command, we will push the image into the DockerHub.
  
  sh "docker push $env.<usernameVariable>/<new-image-name:<tag>>"

🏭Deploy Stage

In this stage, we are deploying our application into the Docker container using docker-compose the file.

sh "docker-cmpose down && docker-compose up -d"
Make sure docker-compose is installed in your system.
Here we have to replace your image name in image statement in Docker-Compose File, Image that you have pushed into the DockerHub. Our Compose-File will fetch that image from DockerHub.
Also, we are exposing the ports here (host-port:container-port) in the ports statement.

Here is the Docker-compose file.

 version : "3.3"
 services :
   Web :
      #Image which we have pushed into DockerHub
      image : deepak1603/django-app-image:v1
      ports :
          - "8000:8000"

Now, In the final step click Apply and Save .

⚙️Execute The Pipeline

Now, Go to the Dashboard/Create project pipeline and click on Build Now.
The pipeline execution will start ...Code will be Colning from GitHub, Docker image will be created, Image tagging will be happening, DockerHub login will be happening, and Pushing image into DockerHub will be happening and finally, the Docker Container will be created with a single click .......Let's see the magic.

⚠️Error - 1

Once built here we are not able to build successfully because we have given the image name in capital letters see the below error.
So we are changing the Image Name here with django-app-image Wherever applicable click on Apply and Save.
```
 sh "docker build -t django-app-image ."
```
Now after saving click on Build Now. again.

⚠️Error - 2

Now, here we got another error which is regarding the Permission denied because Jenkins User is not part of the Docker Group.
We have to add Jenkins User into the Docker Group and Reboot the system

Run the below command in the terminal.

 sudo usermod -a -G docker jenkins 
 sudo systemctl reboot

Now after adding Jenkins User to the Docker Group .
Now after saving click on Build Now. again.

⚠️Error - 3

Now, here we are getting one more error withCredentials step must be called with a body.
So make sure withCredentials is a function as we know, so we have to write the code inside the { } brackets.

Here is the updated code of the withCredentials() function.

 withCredentials([usernamePassword(credentialsId:"DockerHubCredentials", passwordVariable:"dockerPassword", usernameVariable:"dockerUsername")])
    {
    sh "docker tag django-app-image ${env.dockerUsername}/django-app-image:v1"
    sh "docker login -u ${env.dockerUsername} -p ${env.dockerPassword}"
    sh "docker push ${env.dockerUsername}/django-app-image:v1"
    }

After updating the changes again click on Build Now. And let's see this time.

👏🎉🏆Successful Execution 🌟💯

Now, Finally, we are running our pipeline successfully you can see the Console output also the Pipeline Stage View .

We are able to push the image into DockerHub.

Now finally we can check whether the Docker container is created or not.

🕺🕺👏👏🎉🎉 BoooooooooooooMMMM we are able to deploy the application successfully.

Now it's time to access our application from the browser.

To access the application copy the EC2 instance IP Address and paste it into the browser along with :8000, Because our application is running on Port 8000 .

🕺🕺👏👏🎉🎉 BBBBBBBoooooooooooooMMMMMMMMMMMMMM we have successfully deployed our application using the Jenkins pipeline.🕺🕺👏👏🎉🎉

🔝CI/CD Automation

Now, it's time to make our Jenkins pipeline fully automated.

As of now, we are writing our pipeline code into the Jenkins script section.

Now, we will save our script code into GitHub also in the form of Jenkinsfile. and we are fetching the script code from GitHub instead of writing it into Jenkins.

Here is the Jenkins file(same above script code). We will store it at GitHub in the application code itself.

Here is the Jenkins file we will store on GitHub in the application code itself.

📦Executing the Jenkins File from GitHub

To Call Jenkins file From Jenkins, we have to make some modifications in the configure section shown below.

Goto Dashboard and click on Application Pipeline.
Goto Pipeline in Definition select Pipeline script from SCM .
Under SCM select Git.
Under Repositories enter the GitHub URL.
In Brach Specifier under Branches to build Enter your branch name in my case it is main.

In Script Path enter the Jenkinsfile as path then click on Apply and

Save .

🏗️Automate Deployment Using GitHub-Webhook

Now, comes to the CI/CD Automation Using GitHub Webhook .

We will configure our Jenkins file to be executed after any changes are updated in the GitHub Repository.

To make it possible we will use here the Github Webhook.

Go to the Pipeline configure page in Build Triggers.
Select the checkbox GitHub hook trigger for GITScm polling Click on Apply and Save.
Also, we required GitHub Integration plugin got to plugin and install the required plugin.

🔗GitHub-Webhook Configuration

Go to your GitHub repository and click on Settings.
Click on Webhooks and then click on Add webhook.
In the Payload URL field copy and paste your Jenkins environment URL. and at the end of this URL add /github-webhook/
In the Content typeselect: application/json and leave the Secret field empty.
In the Which events would you like to trigger this webhook? section select as per your requirement and click on Add webhook.
Refresh the page until you will get the Right sign ✔

✔🔗Checking The WebHook Integration

We will Change the title from TVS Jupiter Is Amazing to DevOps is Amazing .

After we had changed the code in the repository and committed the changes the magic happens 🕺🕺👏👏🎉🎉... Our Job build execution starts without clinking on Build Now.

WebHook is added to trigger execution of Jenkins jobs based on GitHub events. If anyone in the developer team changes the code, it will automate the Build Now process .

✨Conclusion

✔In this post, we combined GitHub Jenkins Declarative Pipelines and Docker for enhanced CI/CD.

✔We used the sh command to run Docker commands within pipeline stages.

✔Then, we explored Docker Groovy syntax in the script block for smoother image creation and container handling.

✔We have done troubleshooting.

✔We have learned about Jenkinsfile

✔We have implemented the Wbhook call successfully.

Check Out the Video for Complete CI/CD Using Jenkins, Docker, GitHub, and Github-Webhook.

https://www.youtube.com/live/AaVO1Mvr3q4?si=T-AhqSXvIAVtbCba

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