harsha4143 / pythonapp

pythonapp

Jenkins Master Slave Setup

Prerequisites:

1. Launch 2 AWS EC2 Linux instances .
2. Configure Jenkins on an EC2 Linux instance which will act as Master Node.
3. Second EC2 Linux Server will act as a Slave Node for Jenkins.

Security group setting for both EC2 instances should be as follows.

Steps -

1. Install Java on master node
2. Install Jenkins on master node
3. Install java on slave node
4. Create a user and ssh keys on slave node
5. Copy keys on master node
6. Join slave node to master
7. Test the setup

Procedure -

1. Install java,docker and git on master node

              Yum install java-11-openjdk -y
   

2. Install jenkins on master node

           sudo wget -O /etc/yum.repos.d/jenkins.repo    https://pkg.jenkins.io/redhat-stable/jenkins.repo
   

   sudo rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io.key

   yum install jenkins systemctl enable jenkins systemctl start jenkins

   Access URL http://HostIpAddress(public):8080
   We will be asked to enter the password, like below -
   

   When prompted get the password from below location and enter it - cat /var/lib/jenkins/secrets/initialAdminPassword After installing required plugins and asking for a user creation, you will get a default jenkins dashboard as below.

3. Install java,docker and git on slave node.

4. Create a user and ssh keys on slave node. useradd jenkins In order to execute docker statements without sudo permissions use below commands: Usermod -aG docker jenkins Reboot the instance in-order to apply docker permissions.

5. Generate keys on master node and Copy public key to slave node. On master :- First change to jenkins user →su - jenkins -s /bin/bash As jenkins is a service account there wouldn’t be access to /bin/bash so issue above command to change the user and generate keys. Key generation →ssh-keygen -t rsa cd .ssh/ cat id_rsa.pub → copy this o/p On Slave:- Change to jenkins user → su - jenkins Change directory → cd .ssh Create a authorized file → authorized_keys Copy the public key to authorized_keys file.

6. Join slave node to master First make the master node as non-executable by removing the build executors on it. Manage Jenkins →Nodes →master node→configure Change “No of executors” as Zero.

Follow below path in image and add ‘Private Key’ of master as credentials in jenkins.

Select Build Executor Status > New Node > Type - Permanent Select below values - Name - jenkins-slave1 Description - jenkins-slave1 Number of executors - 2 Remote root directory - /home/jenkins/jenkins_node Labels - python Usage - Use this mode as much as possible Launch method - Launch agents via SSH

Host - 172.31.47.100 (Slave worker IP) Credentials - Use the credentials which we have updated on jenkins Host Key Verification Strategy - Know hosts key strategy Save and check that new slave node is added and is in sync

7. Test Jenkins Jobs - Before configuring the jenkins job, we will add a hook to github repository which we will be using when building job.

Payload URL → http://jenkinsHostIP:Port/github-webhook/ Events → Based on git events you can trigger the build. Configure Jenkins Job:- Create "new item" Enter an item name – Python App Chose Pipeline project In build triggers choose “Git scm polling” → Any change in git repository will build the job automatically.

Mention the github repo link, as my repo is a public one it doesn’t require credentials.

Mention the correct branch which you watch for changes,so that it could trigger the build.

There would be a ‘jenkinsfile’ on git repo where we maintain the steps for a build job.