dockerized jenkins with terraform

recently i started using terraform instead of AWS Cloudformation for private projects and messing around. i find it easier to use, it’s looking simpler for non-infra people, documentation is really slick and community is big. ah, and their website is freakin damn cool!

i wanted to create some simple example of terraform template, but also wanted to get my hands on technology that i don’t know or just simply never worked with on daily basis.

so basically…

deploy jenkins on ec2 with terraform

caution: i am deploying to my default vpc and default security group is open to the world, that’s why i didn’t specify any sg’s.

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we will deploy ec2 that installs and starts a jenkins for us.

let’s dive deep into the template

resource "aws_instance" "iron-test" {
  ami           = "ami-06fd78dc2f0b69910"
  instance_type = "t3.micro"
  key_name      = "iron"
}

first, we gonna create basic ec2 that runs ubuntu 18.04 with free tier eligible t3.micro instance type. key_name is key pair created in AWS.

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then, we need to add more space on ebs volume attached to ec2

 root_block_device {
    volume_type           = "gp2"
    volume_size           = "30"
    delete_on_termination = "false"
  }

we are increasing size to 30 gbs which is pretty much overkill cause we basically need only to install docker, so yeah, it’s up to you if u need more/less.

---

  provisioner "remote-exec" {
    inline = [
      "sudo apt update && sudo apt upgrade -y",
      "sudo apt install docker.io -y",
      "sudo systemctl enable --now docker",
      "sudo docker run -d -p 8080:8080 -p 50000:50000 jenkins:2.60.3"
    ]
  }

  connection {
    type        = "ssh"
    host        = self.public_ip
    user        = "ubuntu"
    private_key = file("~/.ssh/iron.pem")
  }

we want to install docker that will run jenkins image on ec2 and it will get exposed on port 8080. we use a provisioner called remote-exec to execute commands in order, one by one, thanks to inline parameter. remember to specify -d parameter in docker run, otherwise terraform will get stuck in docker process.

in the connection block we need to specify connection type, host, user and path to our private key, on our local machine.

---

whole template

resource "aws_instance" "iron-jenkins" {
  ami           = "ami-06fd78dc2f0b69910"
  instance_type = "t3.micro"
  key_name      = "iron"
  root_block_device {
    volume_type           = "gp2"
    volume_size           = "30"
    delete_on_termination = "false"
  }

  provisioner "remote-exec" {
    inline = [
      "sudo apt update && sudo apt upgrade -y",
      "sudo apt install docker.io -y",
      "sudo systemctl enable --now docker",
      "sudo docker run -d -p 8080:8080 -p 50000:50000 jenkins:2.60.3"
    ]
  }

  connection {
    type        = "ssh"
    host        = self.public_ip
    user        = "ubuntu"
    private_key = file("~/.ssh/iron.pem")
  }

  tags = {
    Name = "iron-jenkins"
  }

output "instance-public-ip" {
  value = aws_instance.iron-jenkins.public_ip
}

}

now, after we ran terraform apply we got the public ip of the instance in the outputs of terraform

copy this ip, add :8080 cause that’s a port that jenkins is running on and you should see a welcome page!

additional notes

• it’s fine to use it like this for testing, but in more serious environments you probably shoud add docker volume to jenkins to not lose data
• if your jenkins cannot pull plugins, check if you got correctly configured security group
• same if you cannot access the page