Quick Setup: Jenkins on AWS with Terraform & Bash

# Update the apt package index and install packages to allow apt to use a repository over HTTPS
sudo apt-get update
sudo apt-get install -y apt-transport-https ca-certificates curl software-properties-common

# Add Docker’s official GPG key
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add –

# Set up the stable repository for your architecture (amd64)
sudo add-apt-repository “deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable”

# Update the apt package index again and install the latest version of Docker Engine and containerd
sudo apt-get update
sudo apt-get install -y docker-ce docker-ce-cli containerd.io

# Verify that Docker Engine is installed correctly
sudo docker –version

# Add your user to the docker group to run Docker commands without sudo
sudo usermod -aG docker ${USER}

echo “User added to the docker group. Logging out and back in to apply changes…”

echo “Docker setup completed.”

case $1 in
“green”) COLOR=’33[0;32m’ ;;
“red”) COLOR=’33[0;31m’ ;;
“*”) COLOR=’33[0m’ ;;
esac

echo -e “${COLOR} $2 ${NC}“
}

echo “—————- JENKINS SLAVE NODE SETUP ——————“

print_color “green” “Update apt repository. “
sudo apt update

print_color “green” “Installing Java(openjdk-17-jre)”
sudo apt install openjdk-17-jre -y

echo “—————- SETUP COMPLETE ——————“

#######################################
# Print a message in a given color.
# Arguments:
# Color. eg: green, red
#######################################
function print_color() {
NC=’33[0m’ # No Color

case $1 in
“green”) COLOR=’33[0;32m’ ;;
“red”) COLOR=’33[0;31m’ ;;
“*”) COLOR=’33[0m’ ;;
esac

echo -e “${COLOR} $2 ${NC}“
}

#######################################
# Check the status of a given service. If not active exit script
# Arguments:
# Service Name. eg: firewalld, mariadb
#######################################
function check_service_status() {
service_is_active=$(sudo systemctl is-active $1)

if [ $service_is_active = “active” ]; then
echo “$1 is active and running”
else
echo “$1 is not active/running”
exit 1
fi
}

#######################################
# Check if a given service is enabled to run on boot. If not enabled exit script
# Arguments:
# Service Name. eg: jenkins, mariadb
#######################################
function check_service_enable() {
service_is_enabled=$(sudo systemctl is-enabled $1)

if [ $service_is_enabled = “enabled” ]; then
echo “$1 is enabled”
else
echo “$1 is not enabled”
exit 1
fi
}

#######################################
# Check the status of a firewalld rule. If not configured exit.
# Arguments:
# Port Number. eg: 3306, 80
#######################################
function is_firewalld_rule_configured() {

firewalld_ports=$(sudo firewall-cmd –list-all –zone=public | grep ports)

if [[ $firewalld_ports == *$1* ]]; then
echo “FirewallD has port $1 configured”
else
echo “FirewallD port $1 is not configured”
exit 1
fi
}

echo “—————- Adding Debian package repository of Jenkins to apt repository ——————“

print_color “green” “Download jenkins debian package repository. “
sudo wget -O /usr/share/keyrings/jenkins-keyring.asc
https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key

print_color “green” “Adding jenkins debian package to apt repository. “
echo deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc]
https://pkg.jenkins.io/debian-stable binary/ | sudo tee
/etc/apt/sources.list.d/jenkins.list >/dev/null

print_color “green” “Update apt repository. “
sudo apt update

print_color “green” “Installing fontconfig”
sudo apt install fontconfig -y

print_color “green” “Installing Java(openjdk-17-jre)”
sudo apt install openjdk-17-jre -y

print_color “green” “Installing Jenkins”
sudo apt install jenkins -y

print_color “green” “Enable jenkins service to run on boot”
sudo systemctl enable jenkins

print_color “green” “Starting jenkins service”
sudo systemctl start jenkins

# check Jenkins is enable
check_service_enable jenkins

# check Jenkins is running
check_service_status jenkins

print_color “green” “Opening jenkins default port (8080)”
sudo ufw allow 8080

print_color “green” “Opening OpenSSH port”
sudo ufw allow OpenSSH

print_color “green” “Enable Firewall”
yes | sudo ufw enable

echo “—————- SETUP COMPLETE ——————“

resource “aws_instance” “slave” {
ami = “ami-0e83be366243f524a”
instance_type = “t2.micro”
#running script
user_data = “${file(“path/to/bash/jenkins-slave-setup.sh”)}${file(“path/to/bash/docker-setup.sh”)}“
tags = {
“Name” = “Jenkins Slave”
}
key_name = aws_key_pair.web.id
vpc_security_group_ids = [aws_security_group.primary.id]
}

#Enabling ssh access
resource “aws_key_pair” “web” {
public_key = file(“~/.ssh/id_rsa.pub”)
}

resource “aws_security_group” “primary” {
name = “jenkins_sg”
description = “Allow Jenkins Server Traffic”

# SSH Port
ingress {
from_port = 22
to_port = 22
protocol = “tcp”
cidr_blocks = [“0.0.0.0/0”]
}

ingress {
from_port = 80
to_port = 80
protocol = “tcp”
cidr_blocks = [“0.0.0.0/0”]
}

# Jenkins port
ingress {
from_port = 8080
to_port = 8080
protocol = “tcp”
cidr_blocks = [“0.0.0.0/0”]
}

# Allow all outbound connection over the internet
egress {
protocol = “-1”
from_port = 0
to_port = 0
cidr_blocks = [“0.0.0.0/0”]
}
}
/**
* Creating node on jenkins
* First create a credential to login with username and private key
* Create the private key and public key on the jenkins slave (ssh-keygen)
* Use the private key on the jenkins credential you were creating earlier
* Copy and paste the public key into the authorized_keys file (~/.ssh/authorized_keys) of the slave server
* In the jenkins credentials select Non verifying Verification Strategy
*/