Terraform #1

As our data centre is moving from on-premise site to AWS, there is a need to re-organize infra from the very beginnig. So, creating bunch of VPC, Subnets and instances should be carried on. But how..?

There might be some problems.

1. If I create all these things manually, then I doubt there should be at least one mistake. For example, I could forget to add Name tag or choose IAM role etc..
2. It does take too much time to create all enities. Well.. I can use function provided by AWS to increase setup speed but I’m pretty sure not all the things can be covered.
3. Sharing history with my team can be difficult. What if I create a new instance and don’t share this job with my colleagues? Some can find that I created a new one but most of them can’t easily catch it. We can use logs to check history but just simple logs won’t provide versioning or further features that I need.

So.. aren’t there any *fancy* ways/methods to satisfy above points?

Terraform can be an answer!

Then what is it? What does Terraform exactly do?

According to official Terraform site, Terraform is a tool for building, changing and versioning infrastructure safely and efficiently. Terraform has configuration files which include execution plans and literally execute these plans to build the described infrastructure.

Sources:

• https://www.terraform.io/intro/index.html
• https://learn.hashicorp.com/tutorials/terraform/infrastructure-as-code?in=terraform/aws-get-started

Ok, I got a concept of Terraform. Then let’s use it.

How to use Terraform?

1. Install Terraform

I will test on my mac so I downloaded file for mac os.

After I downloaded a file, I followed this guide to place terraform correctly.

2. Prepare environment

Need to prepare below stuff.

• Terraform
• AWS CLI: https://docs.aws.amazon.com/cli/latest/userguide/install-cliv2-mac.html
• AWS account
• AWS credential (Access key, Secret access key)

In my case, I already have AWS account and installed AWS CLI so I only created AWS credential for this time.

3. Write configuration

# make directory for a test
$ mkdir learn-terraform-aws-instance
# move to the directory
$ cd learn-terraform-aws-instance
# make terraform configuration file
$ touch main.tf
# main.tf
terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 3.27"
    }
  }
required_version = ">= 0.14.9"
}
provider "aws" {
  profile = "default"
  region  = "us-west-2"
}
resource "aws_instance" "soniatest" {
  subnet_id     = "subnet-12345678"
  ami           = "ami-12345678"
  instance_type = "t2.micro"
  ebs_block_device {
    device_name = "/dev/sda1"
    volume_size = 30
    volume_type = "gp2"
  }
  security_groups = ["sg-12345678"]
  key_name        = "test"
  tags = {
    Name = "sonia test"
  }
  volume_tags = {
    Name = "sonia test"
  }
}

Source: https://learn.hashicorp.com/tutorials/terraform/aws-build?in=terraform/aws-get-started

A Terraform configuration file consists of 3 blocks.

• Terraform: Contains Terraform settings
• Provider: Configures the specified providers, in this case ‘aws’. A provider is a plugin that Terraform uses to create and manage resources.
• Resource: Define components of infrastructures. For example, ec2, subnet, VPC etc..

4. Validate configuration file and run to deploy.

terraform init      # create a new configuration file
terraform fmt       # print out the names of files it modified
terraform validate  # check syntax error

5. Create infrastructure

terraform apply

Use web console to check if a new instance has been created.

(In my case, Yes!! I successfully created it without any errors.)

In summary,

a. I installed Terraform on my mac.

b. I also installed AWS CLI on my mac and configured with a command aws configure . (Add my access key, secret access key, default region, profile)
→ Terraform use this information to access aws.

c. Created a new directory in my mac and created a configuration file.

d. Run a few commands to verify configuration file and deploy infrastructure.

As I just mentioned at the beginning, I start using Terraform to make up infrastructure easily and also to share work history with my team efficiently. But.. because Terraform is a powerful tool, I do believe that it can be used beyond what I do.

🍰