Are you looking forward to learn Jenkins right from Zero(installation) to Hero(Build end to end pipelines)? then you are at the right place.

YouTube Video -> https://www.youtube.com/watch?v=zZfhAXfBvVA&list=RDCMUCnnQ3ybuyFdzvgv2Ky5jnAA&index=1

Install Jenkins, configure Docker as agent, set up cicd, deploy applications to k8s and much more.

• Go to AWS Console
• Instances(running)
• Launch instances

Pre-Requisites:

• Java (JDK)

Run all these commands as a ubuntu user Install Java

sudo apt update
sudo apt install openjdk-11-jre -y

Verify Java is Installed

java -version

Now, you can proceed with installing Jenkins, apply the complete command as is

curl -fsSL https://pkg.jenkins.io/debian/jenkins.io-2023.key | sudo tee \
  /usr/share/keyrings/jenkins-keyring.asc > /dev/null
echo deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc] \
  https://pkg.jenkins.io/debian binary/ | sudo tee \
  /etc/apt/sources.list.d/jenkins.list > /dev/null
sudo apt-get update
sudo apt-get install jenkins -y

ps -ef | grep jenkins

you can check the jenkins installation using ps -ef | grep jenkins

**Note: ** By default, Jenkins will not be accessible to the external world due to the inbound traffic restriction by AWS. Open port 8080 in the inbound traffic rules as show below.

• EC2 > Instances > Click on
• In the bottom tabs -> Click on Security
• Security groups
• Add inbound traffic rules as shown in the image (you can just allow TCP 8080 as well, in my case, I allowed All traffic).

http://:8080 [You can get the ec2-instance-public-ip-address from your AWS EC2 console page]

Note: If you are not interested in allowing All Traffic to your EC2 instance 1. Delete the inbound traffic rule for your instance 2. Edit the inbound traffic rule to only allow custom TCP port 8080

After you login to Jenkins, - Run the command to copy the Jenkins Admin Password - sudo cat /var/lib/jenkins/secrets/initialAdminPassword - Enter the Administrator password

Wait for the Jenkins to Install suggested plugins

Create First Admin User or Skip the step [If you want to use this Jenkins instance for future use-cases as well, better to create admin user]

Jenkins Installation is Successful. You can now starting using the Jenkins

• Log in to Jenkins.
• Go to Manage Jenkins > Manage Plugins.
• In the Available tab, search for "Docker Pipeline".
• Select the plugin and click the Install button.
• Restart Jenkins after the plugin is installed.

Wait for the Jenkins to be restarted.

Run the below command to Install Docker

sudo apt update
sudo apt install docker.io -y - Run this on same machine where jenkins is installed
you can also do it in another way installing docker on another ec2 machine but we need to configure the docker installed machine as a slave to the master jenkins

sudo su - 
usermod -aG docker jenkins  - granting the permissions to the jenkins users, to create/run containers and pull the images(jenkins basically comes with the user called jenkins user) - cat /etc/passwd
usermod -aG docker ubuntu - usermod is to grant the access to the jenkins, just making it to the part of docker group, docker installation creates a group called docker
systemctl restart docker
su - jenkins (we can run the docker commands on jenkins)- jenkins users is also about to create the containers and build the images as well

Once you are done with the above steps, it is better to restart Jenkins.

http://<ec2-instance-public-ip>:8080/restart

The docker agent configuration is now successful.

Differences mvn clean install - if we wanna push enterprise archive, jar/war archive to the artifactory like nexus/jfrog. mvn clean package - if we don't have a plan to push on to the artifactory, in my case I don't wanna push the artifact anywhere, I just wanna use in the docker image and publish onto the image repository like dockerhub/ecr mvn clean install or mvn clean package look for the pom.xml filepush pom.xml in a nutshell - is responsible for getting the dependencies runtime and building the application inside the target folder the artifact is stored

only use the jenkins-master for scheduling purpose and run actual worloads on jenkins-slaves(it's a traditional approach)

PROS: use jenkins-master with docker as agents, will try to run the jenkins pipeline(different stages in a pipline) on docker conatiners, docker containers are ease to use, we can modify the dockerfile anytime we want with a desired configuration and can spin up the instance, at some cases we no need of create dockerfile, just we can pull the desired image from dockerhub, we can easily spin-up and tear down the docker conatiners, only if there is request a container is created we used docker as agents in jenkins project setup in terms of cost and efficiency(spinning up and tearing down the docker containers when it's desired)

CONS: in some cases, if your application is a database application this container approach might not work

docker typically run on a docker daemon process i.e., single-source-of-truth, and by default this daemon process isn't accessible by other users, so we need grant the access to docker daemon

in pipeline stuff, if jenkins wanna talk to the sonar it should have authentication token and url of the sonar mvn sonar:sonar - executes the sonar target

in jenkins for adding the credentials for github use the secret text option, username and password won't be there for github from august 2021

this is the test push