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Configure a Linux virtual machine in Azure using Terraform

Infrastructure as Code has become the order of the day. In this article, “Configure a Linux virtual machine in Azure using Terraform”, I seek to guide you to building your first Linux Virtual Machine in Azure. Consider these set of steps as a project to enforce your terraform knowledge.

Configure Your Environment

  • Create providers.tf file
  • Create main.tf file
  • Create vars.tf file
  • Configure Deployment Parts

  • 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
  • Create your vars.tf file

    #Variable file used to store details of repetitive references
    variable "location" {
      description = "availability zone that is a string type variable"
      type    = string
      default = "eastus2"
    }
    
    variable "prefix" {
      type    = string
      default = "emc-eus2-corporate"
    }
    

    Create your providers.tf file

    #Variable file used to store details of repetitive references
    variable "location" {
      type    = string
      default = "eastus2"
    }
    
    variable "prefix" {
      type    = string
      default = "emc-eus2-corporate"
    }
    

    In the next steps, we create the main.tf file and add the following cmdlets.

    Create a virtual network

    #Create virtual network and subnets
    resource "azurerm_virtual_network" "emc-eus2-corporate-network-vnet" {
      name                = "emc-eus2-corporate-network-vnet"
      location            = azurerm_resource_group.emc-eus2-corporate-resources-rg.location
      resource_group_name = azurerm_resource_group.emc-eus2-corporate-resources-rg.name
      address_space       = ["172.20.0.0/16"]
    
      tags = {
        environment = "Production"
      }
    }
    

    Create a subnet

    #Create subnet - presentation tier
    resource "azurerm_subnet" "presentation-subnet" {
      name                 = "presentation-subnet"
      resource_group_name  = azurerm_resource_group.emc-eus2-corporate-resources-rg.name
      virtual_network_name = azurerm_virtual_network.emc-eus2-corporate-network-vnet.name
      address_prefixes     = ["172.20.1.0/24"]
    }
    
    #Create subnet - data access tier
    resource "azurerm_subnet" "data-access-subnet" {
      name                 = "data-access-subnet"
      resource_group_name  = azurerm_resource_group.emc-eus2-corporate-resources-rg.name
      virtual_network_name = azurerm_virtual_network.emc-eus2-corporate-network-vnet.name
      address_prefixes     = ["172.20.2.0/24"]
    }
    

    Create a public IP address

    #Create Public IP Address
    resource "azurerm_public_ip" "emc-eus2-corporate-nic-01-pip" {
      name                = "emc-eus2-corporate-nic-01-pip"
      location            = azurerm_resource_group.emc-eus2-corporate-resources-rg.location
      resource_group_name = azurerm_resource_group.emc-eus2-corporate-resources-rg.name
      allocation_method   = "Dynamic"
    }
    

    Create a network security group and SSH inbound rule

    # Create Network Security Group and rule
    resource "azurerm_network_security_group" "emc-eus2-corporate-nsg" {
      name                = "emc-eus2-corporate-nsg"
      location            = azurerm_resource_group.emc-eus2-corporate-resources-rg.location
      resource_group_name = azurerm_resource_group.emc-eus2-corporate-resources-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 a virtual network interface card

    # Create network interface
    resource "azurerm_network_interface" "corporate-webserver-vm-01-nic" {
      name                = "corporate-webserver-vm-01-nic"
      location            = azurerm_resource_group.emc-eus2-corporate-resources-rg.location
      resource_group_name = azurerm_resource_group.emc-eus2-corporate-resources-rg.name
    
      ip_configuration {
        name                          = "corporate-webserver-vm-01-nic-ip"
        subnet_id                     = azurerm_subnet.presentation-subnet.id
        private_ip_address_allocation = "Dynamic"
        public_ip_address_id          = azurerm_public_ip.corporate-webserver-vm-01-ip.id
      }
    }
    

    Connect the network security group to the network interface

    # Connect the security group to the network interface
    resource "azurerm_network_interface_security_group_association" "corporate-webserver-vm-01-nsg-link" {
      network_interface_id      = azurerm_network_interface.corporate-webserver-vm-01-nic.id
      network_security_group_id = azurerm_network_security_group.emc-eus2-corporate-nsg.id
    }
    

    Create a storage account for boot diagnostics

    # Generate random text for a unique storage account name
    resource "random_id" "randomId" {
      keepers = {
        # Generate a new ID only when a new resource group is defined
        resource_group = azurerm_resource_group.emc-eus2-corporate-resources-rg.name
      }
      byte_length = 8
    }
    

    Create a storage account for boot diagnostics

    # Create storage account for boot diagnostics
    resource "azurerm_storage_account" "corpwebservervm01storage" {
      name                     = "diag${random_id.randomId.hex}"
      location                 = azurerm_resource_group.emc-eus2-corporate-resources-rg.location
      resource_group_name      = azurerm_resource_group.emc-eus2-corporate-resources-rg.name
      account_tier             = "Standard"
      account_replication_type = "LRS"
    }
    

    Create SSH Key

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

    Create a virtual machine

    # Create virtual machine
    resource "azurerm_linux_virtual_machine" "emc-eus2-corporate-webserver-vm-01" {
      name                  = "emc-eus2-corporate-webserver-vm-01"
      location              = azurerm_resource_group.emc-eus2-corporate-resources-rg.location
      resource_group_name   = azurerm_resource_group.emc-eus2-corporate-resources-rg.name
      network_interface_ids = [azurerm_network_interface.corporate-webserver-vm-01-nic.id]
      size                  = "Standard_DC1ds_v3"
    
      os_disk {
        name                 = "corpwebservervm01disk"
        caching              = "ReadWrite"
        storage_account_type = "Premium_LRS"
      }
    
      source_image_reference {
        publisher = "Canonical"
        offer     = "0001-com-ubuntu-server-focal"
        sku       = "20_04-lts-gen2"
        version   = "latest"
      }
    
      computer_name                   = "corporate-webserver-vm-01"
      admin_username                  = "linuxsrvuser"
      disable_password_authentication = true
    
      admin_ssh_key {
        username   = "linuxsrvuser"
        public_key = tls_private_key.linuxsrvuserprivkey.public_key_openssh
      }
    }
    

    Terraform Plan

    The terraform plan command evaluates a Terraform configuration to determine the desired state of all the resources it declares, then compares that desired state to the real infrastructure objects being managed with the current working directory and workspace. It uses state data to determine which real objects correspond to which declared resources, and checks the current state of each resource using the relevant infrastructure provider’s API.

    terraform plan
    

    Terraform Apply

    The terraform apply command performs a plan just like terraform plan does, but then actually carries out the planned changes to each resource using the relevant infrastructure provider’s API. It asks for confirmation from the user before making any changes, unless it was explicitly told to skip approval.

    terraform apply
    

    Command to find an image based on the SKU.

    samuel@Azure:~$ az vm image list -s "2019-Datacenter" --output table
    You are viewing an offline list of images, use --all to retrieve an up-to-date list
    Offer          Publisher               Sku              Urn                                                          UrnAlias           Version
    -------------  ----------------------  ---------------  -----------------------------------------------------------  -----------------  ---------
    WindowsServer  MicrosoftWindowsServer  2019-Datacenter  MicrosoftWindowsServer:WindowsServer:2019-Datacenter:latest  Win2019Datacenter  latest
    samuel@Azure:~$ 
    
    samuel@Azure:~$ az vm image list -s "18.04-LTS" --output table
    You are viewing an offline list of images, use --all to retrieve an up-to-date list
    Offer         Publisher    Sku        Urn                                      UrnAlias    Version
    ------------  -----------  ---------  ---------------------------------------  ----------  ---------
    UbuntuServer  Canonical    18.04-LTS  Canonical:UbuntuServer:18.04-LTS:latest  UbuntuLTS   latest
    

    Command to find an image based on the Publisher.

    samuel@Azure:~$ az vm image list -p "Microsoft" --output table
    You are viewing an offline list of images, use --all to retrieve an up-to-date list
    Offer          Publisher               Sku                                 Urn                                                                             UrnAlias                 Version
    -------------  ----------------------  ----------------------------------  ------------------------------------------------------------------------------  -----------------------  ---------
    WindowsServer  MicrosoftWindowsServer  2022-Datacenter                     MicrosoftWindowsServer:WindowsServer:2022-Datacenter:latest                     Win2022Datacenter        latest
    WindowsServer  MicrosoftWindowsServer  2022-datacenter-azure-edition-core  MicrosoftWindowsServer:WindowsServer:2022-datacenter-azure-edition-core:latest  Win2022AzureEditionCore  latest
    WindowsServer  MicrosoftWindowsServer  2019-Datacenter                     MicrosoftWindowsServer:WindowsServer:2019-Datacenter:latest                     Win2019Datacenter        latest
    
    samuel@Azure:~$ az vm image list -p "Canonical" --output table
    You are viewing an offline list of images, use --all to retrieve an up-to-date list
    Offer         Publisher    Sku        Urn                                      UrnAlias    Version
    ------------  -----------  ---------  ---------------------------------------  ----------  ---------
    UbuntuServer  Canonical    18.04-LTS  Canonical:UbuntuServer:18.04-LTS:latest  UbuntuLTS   latest
    

    At this point, the required pieces to build a Linux Virtual Machine on Azure is complete. It’s time to test your code.

    You can learn more from Hashicorp by visiting the following link.
    This article was helpful in troubleshooting issues with the Ubuntu SKU.