docker-worker

Terraform module: EC2 worker instance with installed Docker, configured SSH access and public IP address to connect

Why

I'm creating AWS EC2 instance just to run some Docker image quite often, after run I'm terminating this instance, because it's not needed anymore. To create new instance I'm always following same steps:

1. Start new instance, configure it's type, disk size
2. Configure security groups
3. Create public IP
4. Configure SSH connection
5. SSH into instance and install docker

I've found a way to automate all these steps using Terraform, this module starts new instance, configures SSH using my local public key, configures security groups and IP address, installs Docker to this instance and configures access for ec2-user just in one command:

terraform apply

also it's flexible enough to configure EC2 type and disk size or to run my local scripts after installation.

Before start

Before using this terraform module make sure you have Terraform installed also you'll need to create SSH key pair and add this key to ssh-agent for EC2 instance provisioning. If you don't have existing key-pair, use ssh-keygen command to generate new, for example to create new key-pair with default params and test name use:

ssh-keygen -f test

then use public key as ssh_pub_key variable, e.g. put it into .tfvars file:

ssh_pub_key = "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC7GIt4h7gEeStrBSGL2yWjAFddcaURRKaRiRyZtt6cZT8hpQ6r3ITWdZEh8lwNuD4d+c7Pxc3nKU3L+/RGO9s+H7AT6ZQYOTBATAwNEYTnVRcTu+WH3juGGxAnT7wXZDRVabhF8+inXgAGef93Ncvvbi5W9OyVml/hNkVzdWMk9yCSM+m+OPW0NLWlX4l/X5yYmGIa9ogAJmPiztI/ILzrp2CMPMhdhL3Wl8pH/By49GW6v2YRC9DU3FSmso4ZuK4rkCL7yIIlm/h3FOUX1lXLcU3AGVsQdZ5yaA1I0lalbYwYSV/2lGyy7zSlestz2MvPaVI/AMB6SSfOa9EZIy97 g4s8@g4s8"

and add private key to ssh-agent:

eval $(ssh-agent)
ssh-add ./test

Configuration

Variables to configure:

Name	Type	Required	Default	Destription
instance_type	string	no	"t2.micro"	EC2 instance type
disk_size	number	no	8	EC2 instance root disk size in GB
tag_name	string	no	"docker-worker"	AWS tag Name which will be added to each resource
ssh_pub_key	string	yes	-	SSH public key
aws_zone	string	yes	-	AWS availability zone, e.g. us-east-2a
init_scripts	list	no	[]	List of paths to scripts to run on setup when creating

Example

Check example in ./example directory.

Add module to your .tf file:

provider "aws" {
  region = "us-east"
  profile = "default"
}

module "my-worker" {
  source = "github.com/g4s8/docker-worker"
  ssh_pub_name = "${var.ssh_pub_name}"
  aws_zone = "us-east-2a"
  instance_type = "t2.medium"
  disk_size = 64
  tag_name = "my-worker"
  init_scripts = "${list("./init.sh")}"
}

output "public-ip" {
  value = "${module.docker-builder.ip}"
}

Call terraform get to get the module, terraform init to init and terraform apply to create worker in your AWS account.

IP address will be printed in the output:

Outputs:

public-ip = 1.2.3.4

then you can access it using command:

ssh ec2-user@1.2.3.4

docker will be installed and configured to use with default ec2-user user.