Adding a Slave Node to Jenkins¶

This guide details the steps to configure a slave node for Jenkins. Follow the instructions below:

Prerequisites¶

Jenkins must be installed and running on the master machine.
Ensure network connectivity between the master and the slave.
Verify SSH access is possible from the master to the slave.

Steps to Configure the Slave Node¶

1. On the Slave Machine¶

Install Java
Jenkins slave requires Java to run. Install it using the following command:
```
apt install openjdk-17-jre-headless
```
Create a Workspace Directory
Create a directory to serve as the Jenkins workspace on the slave machine:
```
mkdir /home/ibtisam/slave-workplace
```

2. On the Master Machine¶

Switch to the Jenkins User
To perform the setup, switch to the Jenkins user:
```
sudo su - jenkins
```
Generate an SSH Key Pair
Generate an SSH key pair to enable password-less authentication between the master and slave:
```
ssh-keygen -t ed25519 -C "jenkins@mint-dell"
```
Save the key pair as /var/lib/jenkins/.ssh/id_ed25519.
Copy the Public Key to the Slave Machine
Copy the public key to the slave machine to enable password-less SSH authentication:
```
ssh-copy-id -i ~/.ssh/id_ed25519 ibtisam@192.168.1.16
```
This command adds the public key to the ~/.ssh/authorized_keys file on the slave.
Ensure that the permissions on the ~/.ssh directory and authorized_keys file are correct:
```
chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys
```
Test Password-less SSH Login
Verify that the master can log in to the slave without a password:
```
ssh ibtisam@192.168.1.16
```
Ensure you can successfully log in without entering a password.
Set SSH Credentials in Jenkins
Add the SSH credentials in Jenkins to establish a connection to the slave:
Username: ibtisam
Private Key: /var/lib/jenkins/.ssh/id_ed25519

¶

Summary¶

By following these steps, the Jenkins master will securely communicate with the slave over SSH, enabling distributed builds and improved resource utilization.

Additional Notes¶

If the slave node still cannot connect, ensure the SSH port (default: 22) is open and not blocked by a firewall.
Double-check the hostname or IP address in the ssh commands.