How to Import an Azure Web Application Firewall Policy into Terraform

Import Azure Web Application Firewall Policy 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 Web Application Firewall Policy 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_web_application_firewall_policy.main
  id = "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/prod-rg/providers/Microsoft.Network/ApplicationGatewayWebApplicationFirewallPolicies/prod-waf"
}

Example azurerm_web_application_firewall_policy configuration

Here is a realistic Azure Web Application Firewall Policy block. Terraback generates a fuller version from your actual resource attributes; this is a minimal, valid starting point.

resource "azurerm_web_application_firewall_policy" "main" {
  name                = "prod-waf"
  resource_group_name = "prod-rg"
  location            = "eastus"

  policy_settings {
    enabled = true
    mode    = "Prevention"
  }

  managed_rules {
    managed_rule_set {
      type    = "OWASP"
      version = "3.2"
    }
  }
}

Gotchas when importing a Azure Web Application Firewall Policy

• The ARM type segment is the long PascalCase 'ApplicationGatewayWebApplicationFirewallPolicies'; copy it exactly, including casing.
• A managed_rules block with at least one managed_rule_set is required.
• This policy is associated to an application gateway (or Front Door) via firewall_policy_id; the gateway is a separate resource.
• policy_settings.mode is Detection or Prevention; switching to Prevention immediately enforces blocking.

Doing it manually with terraform import

The native approach is to write the azurerm_web_application_firewall_policy block by hand, then run terraform import azurerm_web_application_firewall_policy.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