How to Import an Azure Network Security Group into Terraform

Import Azure Network Security Group with Terraback (recommended)

Terraback reverse-engineers your live infrastructure: it reads the Azure Networking resource with read-only credentials, generates the HCL, and produces the exact import block. Two commands take you from a live Azure Network Security Group to managed Terraform.

terraback scan all azure --subscription-id YOUR_ID

terraback azure import --method bulk

The Terraform import block

Terraback emits a Terraform 1.5+ import block like the one below. Because the block lives in your configuration, the import is reviewable in a pull request and repeatable across environments.

import {
  to = azurerm_network_security_group.app
  id = "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/prod-rg/providers/Microsoft.Network/networkSecurityGroups/app-nsg"
}

Example azurerm_network_security_group configuration

Here is a realistic Azure Network Security Group block. Terraback generates a fuller version from your actual resource attributes; this is a minimal, valid starting point.

resource "azurerm_network_security_group" "app" {
  name                = "app-nsg"
  resource_group_name = "prod-rg"
  location            = "eastus"

  security_rule {
    name                       = "allow-https"
    priority                   = 100
    direction                  = "Inbound"
    access                     = "Allow"
    protocol                   = "Tcp"
    source_port_range          = "*"
    destination_port_range     = "443"
    source_address_prefix      = "*"
    destination_address_prefix = "*"
  }
}

Gotchas when importing a Azure Network Security Group

• Rules can be inline security_rule blocks OR separate azurerm_network_security_rule resources, but not both; mixing causes perpetual drift.
• Azure adds default rules (priority 65000+) automatically; do not redeclare them.
• Subnet and NIC associations are separate azurerm_subnet_network_security_group_association / azurerm_network_interface_security_group_association resources.
• Use the singular source_port_range OR plural source_port_ranges for a rule, not both.

Doing it manually with terraform import

The native approach is to write the azurerm_network_security_group block by hand, then run terraform import azurerm_network_security_group.example <import-id> for every resource, one at a time. That works for a handful of resources, but it does not scale: you author all the HCL yourself and repeat the command for each item. Terraback generates the HCL and the import blocks for your whole account in one pass.

Import other Azure resources