Project environment via Infrastructure as Code

This is a Terraform configuration which creates multiple sets of virtual machines for a sandbox. With the default configuration it creates 3 EC2 instances for each of the 7 groups (which makes 21 instances in total) with size t3a.small and using the Ubuntu 22.04LTS x86 image

The instances will be tagged with a Name tag, with a value of group[1-7]-vm[1-3] and a Group tag, with the value group[1-7]

The ssh keypairs used should be available in AWS and named like group[1-7]-key

Usage

You can use this with the following steps:

Necessary setup

1. Setting values for the following either in the variables.tf file or terraform.tfvars or via env_vars:
   • AWS_ACCESS_KEY
   • AWS_SECRET_KEY
   • the VPC ID
   • the subnet ID
   • the security group ID

Optional modifications

2. Modify the setup:
   • the list of groups
   • the list of VM's
   • AMI ID, EC2 instance family / size, etc, go wild

Modifying the configuration like in the following example will create 2 instances for 3 groups, 6 in total.

variable "vm_suffix" {
  description = "List of VMs to be created, also the second part of their names"
  default     = [ "vm1", "vm2"]
}


variable "group_names" {
  description = "List of group names"
  default     = ["group1", "group2", "group3"]
}

RUN(!)

3. Use terraform and create what we have configured

First we have to initialize terraform backend and download/install the provider

foo@bar:~/project_env$ ls
main.tf  outputs.tf  variables.tf

foo@bar:~/project_env$ terraform init

Then just to be sure run plan, let us preview what actions are we planning to take, optionally we can also export this plan so we can apply exactly that later with the option -out envplan

foo@bar:~/project_env$ terraform plan

After this if we're satisfied with our plan, we can go ahead and apply it, optionally if we saved our plan previously we can use that, just put it after the apply like terraform apply envplan

foo@bar:~/project_env$ terraform apply

Authors

Created and hopefully maintained by Sandor Kosztka (@kosztkas)

Reference

• Terraform documentation
• Terraform flatten function
• Terraform distinct function
• Terraform for_each
• nested loops magic - found on 2022/11/14