Using Terraform with Azure – in Terraform

What You’ll Learn 📚

• Core concepts of Terraform and Azure
• Key terminology and definitions
• Step-by-step examples from simple to complex
• Common questions and answers
• Troubleshooting tips

Introduction to Terraform and Azure

Terraform is an open-source tool that allows you to define and provision infrastructure using a simple, declarative language. It’s like having a blueprint for your cloud resources! Azure is Microsoft’s cloud computing platform, offering a wide range of services and tools. Together, they make a powerful combo for managing infrastructure efficiently.

Key Terminology

• Infrastructure as Code (IaC): A method to manage and provision infrastructure through code instead of manual processes.
• Provider: A plugin that allows Terraform to interact with cloud providers like Azure.
• Resource: A component that Terraform manages, such as a virtual machine or storage account.
• State: A file that keeps track of the resources Terraform manages.

Getting Started with a Simple Example

Let’s start with the simplest possible example: creating a resource group in Azure using Terraform.

# Step 1: Install Terraform
$ brew install terraform # For MacOS
$ choco install terraform # For Windows

# Step 2: Create a directory for your Terraform files
$ mkdir terraform-azure-example
$ cd terraform-azure-example

# Step 3: Create a main.tf file
$ touch main.tf

# main.tf
provider "azurerm" {
  features {}
}

resource "azurerm_resource_group" "example" {
  name     = "example-resources"
  location = "East US"
}

# Step 4: Initialize Terraform
$ terraform init

# Step 5: Apply the configuration
$ terraform apply

💡 Lightbulb Moment: Terraform uses a declarative language, meaning you describe the desired state of your infrastructure, and Terraform figures out how to achieve it!

Progressively Complex Examples

Example 1: Adding a Virtual Network

resource "azurerm_virtual_network" "example" {
  name                = "example-network"
  address_space       = ["10.0.0.0/16"]
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
}

Example 2: Creating a Virtual Machine

resource "azurerm_virtual_machine" "example" {
  name                  = "example-vm"
  location              = azurerm_resource_group.example.location
  resource_group_name   = azurerm_resource_group.example.name
  network_interface_ids = [azurerm_network_interface.example.id]
  vm_size               = "Standard_DS1_v2"

  storage_os_disk {
    name              = "example-osdisk"
    caching           = "ReadWrite"
    create_option     = "FromImage"
    managed_disk_type = "Standard_LRS"
  }

  os_profile {
    computer_name  = "hostname"
    admin_username = "adminuser"
    admin_password = "Password1234!"
  }

  os_profile_linux_config {
    disable_password_authentication = false
  }

  source_image_reference {
    publisher = "Canonical"
    offer     = "UbuntuServer"
    sku       = "18.04-LTS"
    version   = "latest"
  }
}

Example 3: Scaling with Multiple Instances

resource "azurerm_virtual_machine" "example" {
  count                 = 3
  name                  = "example-vm-${count.index}"
  location              = azurerm_resource_group.example.location
  resource_group_name   = azurerm_resource_group.example.name
  network_interface_ids = [azurerm_network_interface.example.id]
  vm_size               = "Standard_DS1_v2"

  storage_os_disk {
    name              = "example-osdisk-${count.index}"
    caching           = "ReadWrite"
    create_option     = "FromImage"
    managed_disk_type = "Standard_LRS"
  }

  os_profile {
    computer_name  = "hostname-${count.index}"
    admin_username = "adminuser"
    admin_password = "Password1234!"
  }

  os_profile_linux_config {
    disable_password_authentication = false
  }

  source_image_reference {
    publisher = "Canonical"
    offer     = "UbuntuServer"
    sku       = "18.04-LTS"
    version   = "latest"
  }
}

Common Questions and Answers

1. What is Terraform used for?

   Terraform is used for automating the provisioning of infrastructure across various cloud providers. It helps manage resources efficiently and consistently.

2. Why use Terraform with Azure?

   Using Terraform with Azure allows you to manage Azure resources with a consistent, repeatable process, reducing the risk of human error and improving collaboration.

3. How do I install Terraform?

   You can install Terraform using package managers like Homebrew on MacOS or Chocolatey on Windows. Simply run brew install terraform or choco install terraform.

4. What is a provider in Terraform?

   A provider is a plugin that allows Terraform to interact with cloud providers like Azure, AWS, etc. It defines the resources and operations available for that provider.

5. How does Terraform manage state?

   Terraform uses a state file to keep track of the resources it manages. This file is crucial for determining the current state of your infrastructure and planning changes.

Troubleshooting Common Issues

⚠️ Important: Always back up your state file! Losing it can cause Terraform to lose track of your resources.

• Issue: Terraform apply fails with authentication error.

  Solution: Ensure you have the correct Azure credentials set up. You can authenticate using the Azure CLI or service principal.

• Issue: Resource not found error.

  Solution: Double-check your resource names and configurations. Make sure the resources exist and are correctly referenced in your Terraform files.

• Issue: Terraform plan shows unexpected changes.

  Solution: Review your state file and configuration. Ensure that the state file is up-to-date and matches your current infrastructure.

Practice Exercises

• Create a new Azure Storage Account using Terraform.
• Modify the virtual network example to add a subnet.
• Experiment with different VM sizes and observe the changes.

Remember, practice makes perfect! Keep experimenting and don’t hesitate to explore the official Terraform Azure documentation for more resources and examples.

You’ve got this! 💪