Auto-scaling Group and Launch Configuration

This module creates an AWS auto-scaling group and launch configuration.

Module Usage

module vpc-network
{
    source  = "devops4me/auto-scaling/aws"
    version = "~> 1.0.0"

    in_ami_id         = "ami-12345678"
    in_subnet_ids     = var.in_private_subnet_ids
    in_ssh_public_key = "ssh-rsa AAAAB3NzaC1yc2E...asdf/fghDF ec2 keypair"
    in_instance_type  = "t2.medium"

    in_instance_profile_id = module.ec2-role-profile.out_instance_profile_id
    in_security_group_id   = module.security-group.out_security_group_id
    in_user_data_script    = module.ecs-cluster.out_user_data_script
}

Create new ec2 instances of this type with this AMI ID. Ply them with this public SSH key. Use this instance profile to define the access each instance has to AWS resources. Use this security group to constrain traffic to the instances. Create each instance in one of this list of subnets in a round robin fashion. Run this user data script when the instance boots up.

---

Module Inputs

Input Variable	Type	Description
in_minimum_instances	number	The minimum number of instancees to maintain during cold periods.
in_maximum_instances	number	The maximum number of instances no matter the heat applied.
in_desired_instances	number	The desired number of instances to have up and running.
in_ami_id	string	Create new ec2 instances with this AMI ID.
in_subnet_ids	list	Create each instance in one of this list of subnets in a round robin fashion.
in_ssh_public_key	string	Ply each ec2 instance with this public SSH key.
in_instance_type	string	Create instances from this instance type class.
in_instance_profile_id	string	The ID of the profile that defines each the AWS resource access given to each ec2 instance.
in_security_group_id	string	Use this security group to constrain the traffic to and from the ec2 instances.
in_user_data_script	string	Run this user data script when the instance boots up.

Optional Resource Tag Inputs

Most organisations have a mandatory set of tags that must be placed on AWS resources for cost and billing reports. Typically they denote owners and specify whether environments are prod or non-prod.

Input Variable	Variable Description	Input Example
in_ecosystem	the ecosystem (environment) name these resources belong to	my-app-test or kubernetes-cluster
in_timestamp	the timestamp in resource names helps you identify which environment instance resources belong to	1911021435 as $(date +%y%m%d%H%M%S)
in_description	a human readable description usually stating who is creating the resource and when and where	"was created by $USER@$HOSTNAME on $(date)."

Try echo $(date +%y%m%d%H%M%S) to check your timestamp and echo "was created by $USER@$HOSTNAME on $(date)." to check your description. Here is how you can send these values to terraform.

export TF_VAR_in_timestamp=$(date +%y%m%d%H%M%S)
export TF_VAR_in_description="was created by $USER@$HOSTNAME on $(date)."