Understanding Jenkins Agents

🖥️ Jenkins Master (Server):

• The Jenkins master server orchestrates all workflows and configurations. It schedules jobs and monitors their execution.

🤖 Jenkins Agent:

• An agent is a machine or container connected to the Jenkins master, responsible for executing job steps. Each agent is assigned a unique label for identification.

Scaling with Jenkins Agents

📈 Scaling Up:

• As project requirements grow, scaling becomes necessary. Jenkins facilitates this through master-to-agent connections, allowing distributed job execution.

Pre-requisites

🔧 Preparing the Environment:

• Start with a fresh Ubuntu 22.04 Linux installation.

• Ensure Java (same version as Jenkins master) and Docker are installed.

🛠️ Setting Up Agents:

• Agents need to be set up with separate rights, permissions, and ownership for Jenkins users.

Task-01: Creating Jenkins Agents

🚀 Step 1: Prepare EC2 Instances

• Launch two EC2 instances on AWS: one for the Jenkins master and the other for the agent. Name them accordingly (e.g., Jenkins_master and Jenkins_agent).

    sudo usermod -aG docker $USER 
    sudo usermod -aG docker jenkins
  

🔒 Step 2: Set Up Jenkins and Docker on Master

• Install Jenkins and Docker on the Jenkins_master instance.

• Add both your user and the Jenkins user to the Docker group for permissions.

🔑 Step 3: Generate RSA Key Pair

• Access the terminal on the Jenkins master server and generate an RSA key pair using ssh-keygen.

• Retrieve the public key from the master server for later use.

  

🔗 Step 4: Add Master's Public Key to Slave

• Copy the master server's public key and paste it into the authorized_keys file on the Jenkins_agent.

• Ensure the file is properly saved and exit the text editor.

  

  

  

🔗 Step 5: Verify Connection

• Attempt to SSH into the Jenkins_agent from the Jenkins_master to confirm successful connectivity.

  

🖥️ Step 6: Set Up Jenkins Agent

• In the Jenkins dashboard, navigate to "Manage Jenkins" > "Nodes" and create a new node for the agent.

• Provide details such as description, remote directory, host IP, and credentials.

• Configure the node settings, including the number of executors, remote root directory, labels, launch method (SSH), and host address.

• Select the appropriate private key for authentication and choose the "Non verifying verification strategy" for host key verification

  

  

  

  

  

  

  

  

🚀 Step 7: Launch the Agent

• Finally, click "Launch agent" to establish the connection between the master and slave.

  

With these steps, you've successfully set up a Jenkins master-slave architecture, enhancing your automation capabilities! 🎉

Feel free to customize and elaborate on each step based on your specific setup and requirements. Happy blogging! 🚀🔑🔗

Task-02: Running Jobs on the New Agent

🚀 Executing Previous Jobs:

• Trigger builds for jobs created on Day 26 and Day 27 on the new agent.

• Use labels to direct the master server to trigger builds on the agent.

• Ensure the job runs on the slave machine. Save the pipeline configuration and execute it.

🔁 Troubleshooting:

• If encountering any issues, seek assistance from DevOps groups, Discord, or Telegram communities.

Reflecting on the DevOps Journey

🌟 Happy Learning:

• Keep up the enthusiasm and dedication to continuous learning! 🚀

By following these steps, you'll successfully set up Jenkins agents, enabling distributed job execution and scalability in your CI/CD pipelines. Happy learning and coding! 🎉🛠️