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Create Azure Linux VM with Terraform

This article shows you how to create a complete Linux environment and supporting resources with Terraform. Those resources include a virtual network, subnet, public IP address, and more.

In this article, you learn how to:

  • Create a virtual network
  • Create a subnet
  • Create a public IP address
  • Create a network security group and SSH inbound rule
  • Create a virtual network interface card
  • Connect the network security group to the network interface
  • Create a storage account for boot diagnostics
  • Create SSH key
  • Create a virtual machine
  • Use SSH to connect to virtual machine

Prerequisites

Implement the Terraform code

  1. Create a directory in which to test the sample Terraform code and make it the current directory
  2. Create a file named providers.tf and insert the following code
terraform {
  required_version = ">=0.12"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = "~>2.0"
    }
    random = {
      source  = "hashicorp/random"
      version = "~>3.0"
    }
    tls = {
      source = "hashicorp/tls"
      version = "~>4.0"
    }
  }
}

provider "azurerm" {
  features {}
}
  1. Create a file named main.tf and insert the following code:
resource "random_pet" "rg_name" {
  prefix = var.resource_group_name_prefix
}

resource "azurerm_resource_group" "rg" {
  location = var.resource_group_location
  name     = random_pet.rg_name.id
}

# Create virtual network
resource "azurerm_virtual_network" "my_terraform_network" {
  name                = "myVnet"
  address_space       = ["10.0.0.0/16"]
  location            = azurerm_resource_group.rg.location
  resource_group_name = azurerm_resource_group.rg.name
}

# Create subnet
resource "azurerm_subnet" "my_terraform_subnet" {
  name                 = "mySubnet"
  resource_group_name  = azurerm_resource_group.rg.name
  virtual_network_name = azurerm_virtual_network.my_terraform_network.name
  address_prefixes     = ["10.0.1.0/24"]
}

# Create public IPs
resource "azurerm_public_ip" "my_terraform_public_ip" {
  name                = "myPublicIP"
  location            = azurerm_resource_group.rg.location
  resource_group_name = azurerm_resource_group.rg.name
  allocation_method   = "Dynamic"
}

# Create Network Security Group and rule
resource "azurerm_network_security_group" "my_terraform_nsg" {
  name                = "myNetworkSecurityGroup"
  location            = azurerm_resource_group.rg.location
  resource_group_name = azurerm_resource_group.rg.name

  security_rule {
    name                       = "SSH"
    priority                   = 1001
    direction                  = "Inbound"
    access                     = "Allow"
    protocol                   = "Tcp"
    source_port_range          = "*"
    destination_port_range     = "22"
    source_address_prefix      = "*"
    destination_address_prefix = "*"
  }
}

# Create network interface
resource "azurerm_network_interface" "my_terraform_nic" {
  name                = "myNIC"
  location            = azurerm_resource_group.rg.location
  resource_group_name = azurerm_resource_group.rg.name

  ip_configuration {
    name                          = "my_nic_configuration"
    subnet_id                     = azurerm_subnet.my_terraform_subnet.id
    private_ip_address_allocation = "Dynamic"
    public_ip_address_id          = azurerm_public_ip.my_terraform_public_ip.id
  }
}

# Connect the security group to the network interface
resource "azurerm_network_interface_security_group_association" "example" {
  network_interface_id      = azurerm_network_interface.my_terraform_nic.id
  network_security_group_id = azurerm_network_security_group.my_terraform_nsg.id
}

# Generate random text for a unique storage account name
resource "random_id" "random_id" {
  keepers = {
    # Generate a new ID only when a new resource group is defined
    resource_group = azurerm_resource_group.rg.name
  }

  byte_length = 8
}

# Create storage account for boot diagnostics
resource "azurerm_storage_account" "my_storage_account" {
  name                     = "diag${random_id.random_id.hex}"
  location                 = azurerm_resource_group.rg.location
  resource_group_name      = azurerm_resource_group.rg.name
  account_tier             = "Standard"
  account_replication_type = "LRS"
}

# Create (and display) an SSH key
resource "tls_private_key" "example_ssh" {
  algorithm = "RSA"
  rsa_bits  = 4096
}

# Create virtual machine
resource "azurerm_linux_virtual_machine" "my_terraform_vm" {
  name                  = "myVM"
  location              = azurerm_resource_group.rg.location
  resource_group_name   = azurerm_resource_group.rg.name
  network_interface_ids = [azurerm_network_interface.my_terraform_nic.id]
  size                  = "Standard_DS1_v2"

  os_disk {
    name                 = "myOsDisk"
    caching              = "ReadWrite"
    storage_account_type = "Premium_LRS"
  }

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

  computer_name                   = "myvm"
  admin_username                  = "azureuser"
  disable_password_authentication = true

  admin_ssh_key {
    username   = "azureuser"
    public_key = tls_private_key.example_ssh.public_key_openssh
  }

  boot_diagnostics {
    storage_account_uri = azurerm_storage_account.my_storage_account.primary_blob_endpoint
  }
}
  1. Create a file named variables.tf and insert the following code:
variable "resource_group_location" {
  default     = "eastus"
  description = "Location of the resource group."
}

variable "resource_group_name_prefix" {
  default     = "rg"
  description = "Prefix of the resource group name that's combined with a random ID so name is unique in your Azure subscription."
}
  1. Create a file named outputs.tf and insert the following code:
output "resource_group_name" {
  value = azurerm_resource_group.rg.name
}

output "public_ip_address" {
  value = azurerm_linux_virtual_machine.my_terraform_vm.public_ip_address
}

output "tls_private_key" {
  value     = tls_private_key.example_ssh.private_key_pem
  sensitive = true
}

Initialize Terraform

Run terraform init to initialize the Terraform deployment. This command downloads the Azure modules required to manage your Azure resources.

terraform init

Create a Terraform execution plan

Run terraform plan to create an execution plan.

ConsoleCopy

terraform plan -out main.tfplan

Key points:

  • The terraform plan command creates an execution plan, but doesn’t execute it. Instead, it determines what actions are necessary to create the configuration specified in your configuration files. This pattern allows you to verify whether the execution plan matches your expectations before making any changes to actual resources.
  • The optional -out parameter allows you to specify an output file for the plan. Using the -out parameter ensures that the plan you reviewed is exactly what is applied.
  • To read more about persisting execution plans and security, see the security warning section.

Apply a Terraform execution plan

Run terraform apply to apply the execution plan to your cloud infrastructure.

terraform apply main.tfplan

Key points:

  • The terraform apply command above assumes you previously ran terraform plan -out main.tfplan.
  • If you specified a different filename for the -out parameter, use that same filename in the call to terraform apply.
  • If you didn’t use the -out parameter, call terraform apply without any parameters.

Verify the results

To use SSH to connect to the virtual machine, do the following steps:

  1. Run terraform output to get the SSH private key and save it to a file.
terraform output -raw tls_private_key > id_rsa
  1. Run terraform output to get the virtual machine public IP address.
terraform output public_ip_address
  1. Use SSH to connect to the virtual machine.
ssh -i id_rsa [email protected]<public_ip_address>

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