Terraform: Some Basic Terminologies and Terraform Installation

Introduction to terraform

Terraform is an open source Iac tool, developed by Hashicorp. It allows you to define, manage and provision infrastructure in a safe, predictable, and automated way using a declarative configuration language.

Terraform managed both cloud infrastructure (AWS, Azure, GCP) and on-prem resources (VMware, Kubernetes, and more). With terraform, you can:

• Provision infrastructure: create servers, databases, networks and more
• Update infrastructure: modify existing resources without downtime

• Destroy infrastructure: remove resources when there are no longer needed

• Terraform Providers
  Providers serves as a middleman between terraform and where you are deploying resources to. For example, provider "AWS"

• Hashicorp Configuration Language
  HCl is the language terraform uses to create infrastructure resources and configurations.

• Resources
  These are the infrastructure resources you create with terraform. Example, Resources "aws_ec2_instance"

• Terraform State
  This is like a memory or storage that stores what have been created or modify. It also store the information of the infrastructure resources created or modify.

• Resources Block
  It is a block that defines a specific resource you want to create or manage.

• Resource Type
  It is the specific type of resource you want to create e.g EC2 instance, Google compute engine, VPC e.t.c

• Resource Name
  It is a unique identifier for the resources within your terraform configuration

• Attributes/Machine Type/Region
  It is a property or configuration of the resources often required to create or manage it.

• Variables
  It is like a container that holds information. It's also inputs defined to make the configuration dynamic and reusable.

• Terraform Provisioners
  These are used to execute scripts or commands on a resource after it is created or updated. This allows you to perform additional configuration or setup tasks on the resource, such as installing software, modifying files, or running shell commands.

• Types of Peovisioners

• Remote Executioner or Exec: it execute commands on the remote machine using SSH or WinRM.

• Local Exec: it execute commands on the machine where terraform is running

• File provisioner: it upload files or directories from the machine running terraform to the remote resources

Installing Terraform

Here are the steps to install Terraform on Windows, macOS, and Linux:

Windows

1. Download the Terraform binary: Go to the Terraform downloads page and download the Windows binary (zip file).
2. Extract the binary: Extract the contents of the zip file to a directory, such as C:\Terraform.
3. Add Terraform to the system PATH:
   • Right-click on "This PC" or "Computer" and select "Properties."
   • Click on "Advanced system settings" on the left side.
   • Click on "Environment Variables."
   • Under "System Variables," scroll down and find the "Path" variable, then click "Edit."
   • Click "New" and add the path to the Terraform binary (e.g., C:\Terraform).
4. Verify the installation: Open a new Command Prompt or PowerShell window and run terraform -v to verify that Terraform is installed correctly.

macOS (via Homebrew)

1. Install Homebrew: If you haven't already, install Homebrew by following the instructions on the Homebrew website.
2. Install Terraform: Run brew tap hashicorp/tap and then brew install hashicorp/tap/terraform.
3. Verify the installation: Run terraform -v to verify that Terraform is installed correctly.

Linux

1. Download the Terraform binary: Go to the Terraform downloads page and download the Linux binary (zip file).
2. Extract the binary: Extract the contents of the zip file to a directory, such as /usr/local/bin.
3. Make the binary executable: Run chmod +x /usr/local/bin/terraform to make the binary executable.
4. Verify the installation: Run terraform -v to verify that Terraform is installed correctly.

Alternatively, you can install Terraform on Linux using a package manager like apt (Ubuntu/Debian) or yum (RHEL/CentOS):

Ubuntu/Debian:

1. sudo apt-get update && sudo apt-get install -y gnupg software-properties-common
2. wget -O- https://apt.releases.hashicorp.com/gpg | sudo gpg --dearmor -o /usr/share/keyrings/hashicorp-archive-keyring.gpg
3. echo "deb [signed-by=/usr/share/keyrings/hashicorp-archive-keyring.gpg] https://apt.releases.hashicorp.com $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/hashicorp.list
4. sudo apt update
5. sudo apt-get install terraform

RHEL/CentOS:

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

After installation, verify that Terraform is working correctly by running terraform -v.

You can install Terraform on Windows using Chocolatey. Here's how:

1. Install Chocolatey: If you haven't already, install Chocolatey by following the instructions on the Chocolatey website.

2. Install Terraform: Run the following command in an elevated Command Prompt or PowerShell:
   choco install terraform

3. Verify the installation: Run terraform -v to verify that Terraform is installed correctly.

That's it! Chocolatey will handle the installation and configuration for you.

If you want to install a specific version of Terraform, you can use the --version option:
choco install terraform --version=1.5.2

Replace 1.5.2 with the desired version.

Using Chocolatey makes it easy to manage and update Terraform on your Windows system.