Creating an ec2 instance using the Hackney module

Overview#

This module deploys EC2 instances in the opionated way that we use them in Hackney. It supports the deployment of a Bastion host for external access and is also pre-configured to enable connection to AppStream.

Usage#

Declare the module and provide the required inputs and optional inputs as needed:

module "ec2s" {
source = "../../modules/aws-ec2-lbh/module"
tags = module.tags.values
vpc_id = "vpc-xxxx"
subnet_ids = ["subnet-xxxxxa", "subnet-xxxxxb", "subnet-xxxxxc"]
ec2_instances = local.ec2_instances
}

The ec2_instances is a map variable that defines the required EC2 configuration. This could be read from external YAML or JSON files, using yamldecode() or jsondecode() functions:

locals {
ec2_instances = yamldecode(file("path/to/ec2.yml"))
}

Alternatively, the variable can be defined inside a tfvars file or constructed dynamically. Below are some example configurations:

HCL

ec2_instances = {
"app" = {
"allow_appstream" = true
"ami" = "ami-0c6043f6e8a4652bc"
"ebs_block_devices" = {
"/dev/sdb" = 3000
"/dev/sdc" = 500
}
"egress_rules" = ["all-all"]
"ingress_cidr_blocks" = ["0.0.0.0/0"]
"ingress_rules" = ["http-80-tcp", "all-icmp"]
"instance_count" = 1
"instance_type" = "c4.2xlarge"
"root_block_device_volume_size" = 100
"user_data" = "#! /bin/bash echo \"HelloWorld\"\n"
},
"db" = {
"ami" = "ami-0c6043f6e8a4652bc"
"ingress_rules" = ["http-80-tcp", "all-icmp"]
"instance_count" = 1
"instance_type" = "c4.2xlarge"
"root_block_device_volume_size" = 100
}
}

YAML:

---
app:
# Required
ami: ami-0c6043f6e8a4652bc
# Required
instance_type: c4.2xlarge
# Required
root_block_device_volume_size: 100
# Required
ingress_rules:
- http-80-tcp
- all-icmp
# Optional - defaults to ["0.0.0.0/0"]
ingress_cidr_blocks:
- 0.0.0.0/0
# Optional - defaults to ["all-all"]
egress_rules:
- all-all
# Optional - defaults to false
allow_appstream: true
# Optional defaults to []
ebs_block_devices:
/dev/sdb: 3000
/dev/sdc: 500
# Optional - defaults to empty -
user_data: >
#! /bin/bash
echo "HelloWorld"
db:
# Required
ami: ami-0c6043f6e8a4652bc
# Required
instance_type: c4.2xlarge
# Required
root_block_device_volume_size: 100
# Required
ingress_rules:
- http-80-tcp
- all-icmp

JSON

{
"app": {
"allow_appstream": true,
"ami": "ami-0c6043f6e8a4652bc",
"ebs_block_devices": {
"/dev/sdb": 3000,
"/dev/sdc": 500
},
"egress_rules": [
"all-all"
],
"ingress_cidr_blocks": [
"0.0.0.0/0"
],
"ingress_rules": [
"http-80-tcp",
"all-icmp"
],
"instance_count": 1,
"instance_type": "c4.2xlarge",
"root_block_device_volume_size": 100,
"user_data": "#! /bin/bash echo \"HelloWorld\"\n"
},
"db": {
"ami": "ami-0c6043f6e8a4652bc",
"ingress_rules": [
"http-80-tcp",
"all-icmp"
],
"instance_count": 1,
"instance_type": "c4.2xlarge",
"root_block_device_volume_size": 100
}
}

Required Module Variables#

See 01-inputs-required.tf

Optional Module Variables#

See 02-inputs-optional.tf

Module Output Variables#

See 99-outputs.tf