In terraform, how can I pull a Docker image on the target?

Question

Terraform v0.12.x

I'm creating an AWS EC2 instance with the aws_instance resource, and I want to pull a Docker image inside the target (I have it set up with the correct AWS credentials). I see the docker_image resource, but that pulls the image on my laptop and not on the target.

How can I pull a docker image on the target? I know I can use user_data, but is there another way?

Thanks.

Terraform is more of a tool for infrastructure. Provisioning things on an EC2 instance is more of an Ansible thing. Also you could try Packer from Hashicorp to build an AMI that has it all set the way you want it in conjunction with Anisble and then have terraform provision the aws_instance all set and ready to go with your custom AMI — Michael Papile
Yes I'm doing all this, but wanting to explore in Terraform, thanks. You may put your comment in an answer and I'll accept it, if you wish. — Chris F

Amit Baranes Amit Baranes · Accepted Answer · 2020-11-12T20:16:40

This is possible, the following example is based on this repo.

main.tf -

provider "aws" {
    region = "ap-southeast-1"
}

# Creating key_pair for SSH in AWS instance

resource "tls_private_key" "createkey" {
  algorithm = "RSA"
  rsa_bits  = 4096
}


resource "aws_key_pair" "generated_key" {
  key_name   = "terraform-key"
  public_key = tls_private_key.createkey.public_key_openssh
}

resource "null_resource" "savekey"  {
  depends_on = [
    tls_private_key.createkey,
  ]
    provisioner "local-exec" {
        command = "echo  '${tls_private_key.createkey.private_key_pem}' > wordpress_key.pem"
    }
}



# Creating AWS EC2 Instance with previously created key pair and security group

resource "aws_instance" "webserver" {
  #  Change ami id according to your region
  #  https://github.com/losDaniel/spot-connect/blob/d474cbbf8c2aa02127c445c303d0ac435d88a0d2/build/lib/spot_connect/data/ami_data.csv
  ami           = "ami-0fe1ff5007e7820fd" 
  instance_type = "t2.micro"
  key_name = aws_key_pair.generated_key.key_name
  security_groups = [ "open" ] # your security group name

  connection {
    type     = "ssh"
    user     = "ec2-user"
    private_key = tls_private_key.createkey.private_key_pem
    host     = aws_instance.webserver.public_ip
  }

  provisioner "remote-exec" {
    inline = [
    "sudo yum update -y",
    "sudo yum install git -y",
    "sudo yum install docker -y",
    "sudo service docker start",
    "sudo usermod -a -G docker ec2-user",
    "sudo curl -L \"https://github.com/docker/compose/releases/download/1.26.0/docker-compose-$(uname -s)-$(uname -m)\" -o /usr/local/bin/docker-compose",
    "sudo chmod +x /usr/local/bin/docker-compose",
    "docker pull mysql:5.7",
    "docker pull wordpress",
    "docker pull phpmyadmin/phpmyadmin",
    "mkdir wordpress_data"   
    ]
  }

  tags = {
    Name = "terraform-docker-pull"
  }

}

# Storing IP address in file
resource "null_resource" "getIp"  {
    provisioner "local-exec" {
        command = "echo  ${aws_instance.webserver.public_ip} > publicip.txt"
    }
}

In case you want to work against a different region, update the ami accordingly.

Verify docker pulled into the machine :

In terraform, how can I pull a Docker image on the target?

1 Answers