Create a spoke network in Azure using Terraform
Terraform enables the definition, preview, and deployment of cloud infrastructure. Using Terraform, you create configuration files using HCL syntax. The HCL syntax allows you to specify the cloud provider - such as Azure - and the elements that make up your cloud infrastructure. After you create your configuration files, you create an execution plan that allows you to preview your infrastructure changes before they're deployed. Once you verify the changes, you apply the execution plan to deploy the infrastructure.
In this article, you implement two separate spoke networks to demonstrate separation of workloads. The networks share common resources using hub virtual network. Spokes can be used to isolate workloads in their own VNets, managed separately from other spokes. Each workload might include multiple tiers, with multiple subnets connected through Azure load balancers.
In this article, you learn how to:
- Implement the Spoke VNets in hub-spoke topology
- Create Virtual machines in the spoke networks
- Establish virtual network peerings with the hub networks
1. Configure your environment
- Azure subscription: If you don't have an Azure subscription, create a free account before you begin.
Configure Terraform: If you haven't already done so, configure Terraform using one of the following options:
Create a hub and spoke hybrid network topology with Terraform in Azure.
Create a hub virtual network appliance with Terraform in Azure.
2. Implement the Terraform code
Two spoke scripts are created in this section. Each script defines a spoke virtual network and a virtual machine for the workload. A peered virtual network from hub to spoke is then created.
Make the example directory created in the first article of this series the current directory.
Create a file named
spoke1.tf
and insert the following code:locals { spoke1-location = "eastus" spoke1-resource-group = "spoke1-vnet-rg" prefix-spoke1 = "spoke1" } resource "azurerm_resource_group" "spoke1-vnet-rg" { name = local.spoke1-resource-group location = local.spoke1-location } resource "azurerm_virtual_network" "spoke1-vnet" { name = "spoke1-vnet" location = azurerm_resource_group.spoke1-vnet-rg.location resource_group_name = azurerm_resource_group.spoke1-vnet-rg.name address_space = ["10.1.0.0/16"] tags = { environment = local.prefix-spoke1 } } resource "azurerm_subnet" "spoke1-mgmt" { name = "mgmt" resource_group_name = azurerm_resource_group.spoke1-vnet-rg.name virtual_network_name = azurerm_virtual_network.spoke1-vnet.name address_prefixes = ["10.1.0.64/27"] } resource "azurerm_subnet" "spoke1-workload" { name = "workload" resource_group_name = azurerm_resource_group.spoke1-vnet-rg.name virtual_network_name = azurerm_virtual_network.spoke1-vnet.name address_prefixes = ["10.1.1.0/24"] } resource "azurerm_virtual_network_peering" "spoke1-hub-peer" { name = "spoke1-hub-peer" resource_group_name = azurerm_resource_group.spoke1-vnet-rg.name virtual_network_name = azurerm_virtual_network.spoke1-vnet.name remote_virtual_network_id = azurerm_virtual_network.hub-vnet.id allow_virtual_network_access = true allow_forwarded_traffic = true allow_gateway_transit = false use_remote_gateways = true depends_on = [azurerm_virtual_network.spoke1-vnet, azurerm_virtual_network.hub-vnet , azurerm_virtual_network_gateway.hub-vnet-gateway] } resource "azurerm_network_interface" "spoke1-nic" { name = "${local.prefix-spoke1}-nic" location = azurerm_resource_group.spoke1-vnet-rg.location resource_group_name = azurerm_resource_group.spoke1-vnet-rg.name enable_ip_forwarding = true ip_configuration { name = local.prefix-spoke1 subnet_id = azurerm_subnet.spoke1-mgmt.id private_ip_address_allocation = "Dynamic" } } resource "azurerm_virtual_machine" "spoke1-vm" { name = "${local.prefix-spoke1}-vm" location = azurerm_resource_group.spoke1-vnet-rg.location resource_group_name = azurerm_resource_group.spoke1-vnet-rg.name network_interface_ids = [azurerm_network_interface.spoke1-nic.id] vm_size = var.vmsize storage_image_reference { publisher = "Canonical" offer = "UbuntuServer" sku = "16.04-LTS" version = "latest" } storage_os_disk { name = "myosdisk1" caching = "ReadWrite" create_option = "FromImage" managed_disk_type = "Standard_LRS" } os_profile { computer_name = "${local.prefix-spoke1}-vm" admin_username = var.username admin_password = var.password } os_profile_linux_config { disable_password_authentication = false } tags = { environment = local.prefix-spoke1 } } resource "azurerm_virtual_network_peering" "hub-spoke1-peer" { name = "hub-spoke1-peer" resource_group_name = azurerm_resource_group.hub-vnet-rg.name virtual_network_name = azurerm_virtual_network.hub-vnet.name remote_virtual_network_id = azurerm_virtual_network.spoke1-vnet.id allow_virtual_network_access = true allow_forwarded_traffic = true allow_gateway_transit = true use_remote_gateways = false depends_on = [azurerm_virtual_network.spoke1-vnet, azurerm_virtual_network.hub-vnet, azurerm_virtual_network_gateway.hub-vnet-gateway] }
Create a file named
spoke2.tf
and insert the following code:locals { spoke2-location = "eastus" spoke2-resource-group = "spoke2-vnet-rg" prefix-spoke2 = "spoke2" } resource "azurerm_resource_group" "spoke2-vnet-rg" { name = local.spoke2-resource-group location = local.spoke2-location } resource "azurerm_virtual_network" "spoke2-vnet" { name = "${local.prefix-spoke2}-vnet" location = azurerm_resource_group.spoke2-vnet-rg.location resource_group_name = azurerm_resource_group.spoke2-vnet-rg.name address_space = ["10.2.0.0/16"] tags = { environment = local.prefix-spoke2 } } resource "azurerm_subnet" "spoke2-mgmt" { name = "mgmt" resource_group_name = azurerm_resource_group.spoke2-vnet-rg.name virtual_network_name = azurerm_virtual_network.spoke2-vnet.name address_prefixes = ["10.2.0.64/27"] } resource "azurerm_subnet" "spoke2-workload" { name = "workload" resource_group_name = azurerm_resource_group.spoke2-vnet-rg.name virtual_network_name = azurerm_virtual_network.spoke2-vnet.name address_prefixes = ["10.2.1.0/24"] } resource "azurerm_virtual_network_peering" "spoke2-hub-peer" { name = "${local.prefix-spoke2}-hub-peer" resource_group_name = azurerm_resource_group.spoke2-vnet-rg.name virtual_network_name = azurerm_virtual_network.spoke2-vnet.name remote_virtual_network_id = azurerm_virtual_network.hub-vnet.id allow_virtual_network_access = true allow_forwarded_traffic = true allow_gateway_transit = false use_remote_gateways = true depends_on = [azurerm_virtual_network.spoke2-vnet, azurerm_virtual_network.hub-vnet, azurerm_virtual_network_gateway.hub-vnet-gateway] } resource "azurerm_network_interface" "spoke2-nic" { name = "${local.prefix-spoke2}-nic" location = azurerm_resource_group.spoke2-vnet-rg.location resource_group_name = azurerm_resource_group.spoke2-vnet-rg.name enable_ip_forwarding = true ip_configuration { name = local.prefix-spoke2 subnet_id = azurerm_subnet.spoke2-mgmt.id private_ip_address_allocation = "Dynamic" } tags = { environment = local.prefix-spoke2 } } resource "azurerm_virtual_machine" "spoke2-vm" { name = "${local.prefix-spoke2}-vm" location = azurerm_resource_group.spoke2-vnet-rg.location resource_group_name = azurerm_resource_group.spoke2-vnet-rg.name network_interface_ids = [azurerm_network_interface.spoke2-nic.id] vm_size = var.vmsize storage_image_reference { publisher = "Canonical" offer = "UbuntuServer" sku = "16.04-LTS" version = "latest" } storage_os_disk { name = "myosdisk1" caching = "ReadWrite" create_option = "FromImage" managed_disk_type = "Standard_LRS" } os_profile { computer_name = "${local.prefix-spoke2}-vm" admin_username = var.username admin_password = var.password } os_profile_linux_config { disable_password_authentication = false } tags = { environment = local.prefix-spoke2 } } resource "azurerm_virtual_network_peering" "hub-spoke2-peer" { name = "hub-spoke2-peer" resource_group_name = azurerm_resource_group.hub-vnet-rg.name virtual_network_name = azurerm_virtual_network.hub-vnet.name remote_virtual_network_id = azurerm_virtual_network.spoke2-vnet.id allow_virtual_network_access = true allow_forwarded_traffic = true allow_gateway_transit = true use_remote_gateways = false depends_on = [azurerm_virtual_network.spoke2-vnet, azurerm_virtual_network.hub-vnet, azurerm_virtual_network_gateway.hub-vnet-gateway] }
Troubleshoot Terraform on Azure
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