Low Orbit Flux Logo 2 F

HashiCorp Terraform

You might want to cover these before starting with Terraform ( or come back to them as needed ):

Learn Terraform:

Install Terraform

Manual Install

You can either build from source or just download a binary. This can be done for Linux, Mac OSX, or Windows.

To download a binary just go to this URL, download the package for your system, and unzip it:

Compile from source instead of downloading the binary:


git clone https://github.com/hashicorp/terraform.git
cd terraform
go install

Once you have either built or downloaded the binary you will need to either place it somewhere on your path or change your path.

For Linux or Mac OSX


echo $PATH
sudo mv ~/Downloads/terraform /usr/local/bin/

Verify that it works with the help command:


terraform -help       # get help
terraform -help plan  # get help for sub command

Setup tab completion for BASH:

touch ~/.bashrc


terraform -install-autocomplete

Setup tab completion for Zsh:

vi ~/.zshrc


terraform -install-autocomplete

OSX Homebrew

Install:


brew tap hashicorp/tap                 # install repo
brew install hashicorp/tap/terraform   # install Terraform

Update:


brew update                           # update Homebrew
brew upgrade hashicorp/tap/terraform  # update Terraform

Windows with Chocolatey


choco install terraform

Debian / Ubuntu


sudo apt-get update && sudo apt-get install -y gnupg software-properties-common curl
curl -fsSL https://apt.releases.hashicorp.com/gpg | sudo apt-key add -
sudo apt-add-repository "deb [arch=amd64] https://apt.releases.hashicorp.com $(lsb_release -cs) main"
sudo apt-get update && sudo apt-get install terraform

RHEL / CentOS - YUM


sudo yum install -y yum-utils
sudo yum-config-manager --add-repo https://rpm.releases.hashicorp.com/RHEL/hashicorp.repo
sudo yum -y install terraform

Fedora - DNF


sudo dnf install -y dnf-plugins-core
sudo dnf config-manager --add-repo https://rpm.releases.hashicorp.com/fedora/hashicorp.repo
sudo dnf -y install terraform

Amazon Linux


sudo yum install -y yum-utils
sudo yum-config-manager --add-repo https://rpm.releases.hashicorp.com/AmazonLinux/hashicorp.repo
sudo yum -y install terraform

Quick Docker Example

Create a directory and enter it:


mkdir test1
cd test1

Define your infrastructure:

main.tf


terraform {
  required_providers {
    docker = {
      source  = "kreuzwerker/docker"
      version = "~> 2.13.0"
    }
  }
}

provider "docker" {}

resource "docker_image" "nginx" {
  name         = "nginx:latest"
  keep_locally = false
}

resource "docker_container" "nginx" {
  image = docker_image.nginx.latest
  name  = "test1"
  ports {
    internal = 80
    external = 8000
  }
}

Change the providor for Windows:


provider "docker" {
  host    = "npipe:////.//pipe//docker_engine"
}

Use these commands:


terraform init
terraform apply
docker ps
terraform destroy

Build Infrastructure (AWS)

Prerequisites:

NOTE - AWS generally costs money and you will probably incur charges .

Export variables for your credentials:


export AWS_ACCESS_KEY_ID="xxxxxxxx"
export AWS_SECRET_ACCESS_KEY="xxxxxxxx"
export AWS_DEFAULT_REGION="xxxxxxxx"

Create and enter directory:


mkdir deploy1
cd deploy1

Create a .tf file like this:

vi 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" "app_server" {
  ami           = "ami-830c94e3"
  instance_type = "t2.micro"

  tags = {
    Name = "ExampleAppServerInstance"
  }
}

NOTE

Terraform block:

Provider block:

Resource block:

Download / install providers:


terraform init

Fix formatting for all of your files:


terraform fmt

Check if configs are valid:


terraform validate

Apply the changes to actually create a resource:


terraform apply

Inspect current state:


terraform show

List resources in project state:


terraform state list

You can set these if needed:


vpc_security_group_ids = ["sg-0077..."]
subnet_id              = "subnet-923a..."

Updates / Changes

Just edit your .tf files and run:


terraform apply

Destroy Infrastructure

Just run this:


terraform destroy

Variables

All files with a .tf extension are loaded so the names don’t matter.

variables.tf

variable "instance_name" {
  description = "Value of the Name tag for the EC2 instance"
  type        = string
  default     = "DifferentDefaultAppServerInstance"
}

Access your variable like this:

main.tf

...
   tags = {
     Name = var.instance_name
   }
...

Specify variable when applying changes like this:


terraform apply -var "instance_name=Server1"

Outputs to Query Data

These allow you to easily query useful data.

Define outputs:

outputs.tf



output "instance_id" {
  description = "ID of the EC2 instance"
  value       = aws_instance.app_server.id
}

output "instance_public_ip" {
  description = "Public IP address of the EC2 instance"
  value       = aws_instance.app_server.public_ip
}

Apply the new config:


terraform apply

Query output values:


terraform output

Remote state storage

main.tf


terraform {
  cloud {
    organization = "ORG_NAME"
    workspaces {
      name = "Workspace1"
    }
  }
....

Login:


terraform login



terraform init

Remove the state file:


rm terraform.tfstate