cloud-nat-migration-guide.md

NAT Gateway to Cloud NAT Migration Guide

This guide explains how to migrate from an instance-based NAT gateway to the managed Cloud NAT resource. For more information see the following documentation.

Configure a Cloud NAT

In the same region your instance-based NAT gateway is located, configure a Cloud NAT resource.

Using Console or API

Use these instructions to configure a Cloud NAT in the same region as your instance-based NAT gateway.

Using Cloud NAT Terraform Module

The instructions below are intended for Terraform 0.12. We recommend upgrading your resources to Terraform 0.12, but if you need a Terraform 0.11.x-compatible version of Cloud NAT, use version 0.1.0 of terraform-google-cloud-nat.

Create a Cloud NAT resource in your region. If you do not have a Cloud Router, create one using the google_compute_router resource.

resource "google_compute_router" "router" {
  name    = "load-balancer-module-router"
  region  = var.region
  network = var.network
}

module "cloud_nat" {
  source     = "terraform-google-modules/cloud-nat/google"
  version    = "~> 1.0.0"
  project_id = var.project_id
  region     = var.region
  name       = "load-balancer-module-nat"
  router     = google_compute_router.router.name
}

Remove static routes

Delete the static routes that are sending traffic to the instanced-based NAT gateway.

• If created via NAT gateway module, routes will be named [prefix]nat-[zone]
• If created via console or API, routes may be called: no-ip-internet-route, natroute1, natroute2, natroute3

Once removed, confirm that traffic is flowing through Cloud NAT from an instance in your network.

Remove NAT gateway

Delete your NAT gateway instance(s).

• If created via NAT gateway module, remove the instance of the module from Terraform and re-apply
• If created via console or API, delete your instance-based NAT gateways

Note for users of squid proxy functionality in NAT gateway

Cloud NAT does not support squid or network proxy functionality. To use a squid proxy, see the following documentation.