Terraform examples for a regional internal Application Load Balancer

You can use the following examples to deploy a sample regional internal Application Load Balancer.

If you are new to using Terraform for Google Cloud, see Get started with Terraform .

Regional internal Application Load Balancer with a MIG backend

You can use Terraform resources to bring up an internal HTTP load balancer with a managed instance group backend.

For information about the load balancer setup, see the primary setup guide .

 # VPC network
resource "google_compute_network" "ilb_network" {
  name                    = "l7-ilb-network"
  provider                = google-beta
  auto_create_subnetworks = false
}

# proxy-only subnet
resource "google_compute_subnetwork" "proxy_subnet" {
  name          = "l7-ilb-proxy-subnet"
  provider      = google-beta
  ip_cidr_range = "10.0.0.0/24"
  region        = "europe-west1"
  purpose       = "REGIONAL_MANAGED_PROXY"
  role          = "ACTIVE"
  network       = google_compute_network.ilb_network.id
}

# backend subnet
resource "google_compute_subnetwork" "ilb_subnet" {
  name          = "l7-ilb-subnet"
  provider      = google-beta
  ip_cidr_range = "10.0.1.0/24"
  region        = "europe-west1"
  network       = google_compute_network.ilb_network.id
}

# forwarding rule
resource "google_compute_forwarding_rule" "google_compute_forwarding_rule" {
  name                  = "l7-ilb-forwarding-rule"
  provider              = google-beta
  region                = "europe-west1"
  depends_on            = [google_compute_subnetwork.proxy_subnet]
  ip_protocol           = "TCP"
  load_balancing_scheme = "INTERNAL_MANAGED"
  port_range            = "80"
  target                = google_compute_region_target_http_proxy.default.id
  network               = google_compute_network.ilb_network.id
  subnetwork            = google_compute_subnetwork.ilb_subnet.id
  network_tier          = "PREMIUM"
}

# HTTP target proxy
resource "google_compute_region_target_http_proxy" "default" {
  name     = "l7-ilb-target-http-proxy"
  provider = google-beta
  region   = "europe-west1"
  url_map  = google_compute_region_url_map.default.id
}

# URL map
resource "google_compute_region_url_map" "default" {
  name            = "l7-ilb-regional-url-map"
  provider        = google-beta
  region          = "europe-west1"
  default_service = google_compute_region_backend_service.default.id
}

# backend service
resource "google_compute_region_backend_service" "default" {
  name                  = "l7-ilb-backend-subnet"
  provider              = google-beta
  region                = "europe-west1"
  protocol              = "HTTP"
  load_balancing_scheme = "INTERNAL_MANAGED"
  timeout_sec           = 10
  health_checks         = [google_compute_region_health_check.default.id]
  backend {
    group           = google_compute_region_instance_group_manager.mig.instance_group
    balancing_mode  = "UTILIZATION"
    capacity_scaler = 1.0
  }
}

# instance template
resource "google_compute_instance_template" "instance_template" {
  name         = "l7-ilb-mig-template"
  provider     = google-beta
  machine_type = "e2-small"
  tags         = ["http-server"]

  network_interface {
    network    = google_compute_network.ilb_network.id
    subnetwork = google_compute_subnetwork.ilb_subnet.id
    access_config {
      # add external ip to fetch packages
    }
  }
  disk {
    source_image = "debian-cloud/debian-12"
    auto_delete  = true
    boot         = true
  }

  # install nginx and serve a simple web page
  metadata = {
    startup-script = <<-EOF1
      #! /bin/bash
      set -euo pipefail

      export DEBIAN_FRONTEND=noninteractive
      apt-get update
      apt-get install -y nginx-light jq

      NAME=$(curl -H "Metadata-Flavor: Google" "http://metadata.google.internal/computeMetadata/v1/instance/hostname")
      IP=$(curl -H "Metadata-Flavor: Google" "http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/ip")
      METADATA=$(curl -f -H "Metadata-Flavor: Google" "http://metadata.google.internal/computeMetadata/v1/instance/attributes/?recursive=True" | jq 'del(.["startup-script"])')

      cat <<EOF > /var/www/html/index.html
      <pre>
      Name: $NAME
      IP: $IP
      Metadata: $METADATA
      </pre>
      EOF
    EOF1
  }
  lifecycle {
    create_before_destroy = true
  }
}

# health check
resource "google_compute_region_health_check" "default" {
  name     = "l7-ilb-hc"
  provider = google-beta
  region   = "europe-west1"
  http_health_check {
    port_specification = "USE_SERVING_PORT"
  }
}

# MIG
resource "google_compute_region_instance_group_manager" "mig" {
  name     = "l7-ilb-mig1"
  provider = google-beta
  region   = "europe-west1"
  version {
    instance_template = google_compute_instance_template.instance_template.id
    name              = "primary"
  }
  base_instance_name = "vm"
  target_size        = 2
}

# allow all access from IAP and health check ranges
resource "google_compute_firewall" "fw_iap" {
  name          = "l7-ilb-fw-allow-iap-hc"
  provider      = google-beta
  direction     = "INGRESS"
  network       = google_compute_network.ilb_network.id
  source_ranges = ["130.211.0.0/22", "35.191.0.0/16", "35.235.240.0/20"]
  allow {
    protocol = "tcp"
  }
}

# allow http from proxy subnet to backends
resource "google_compute_firewall" "fw_ilb_to_backends" {
  name          = "l7-ilb-fw-allow-ilb-to-backends"
  provider      = google-beta
  direction     = "INGRESS"
  network       = google_compute_network.ilb_network.id
  source_ranges = ["10.0.0.0/24"]
  target_tags   = ["http-server"]
  allow {
    protocol = "tcp"
    ports    = ["80", "443", "8080"]
  }
}

# test instance
resource "google_compute_instance" "vm_test" {
  name         = "l7-ilb-test-vm"
  provider     = google-beta
  zone         = "europe-west1-b"
  machine_type = "e2-small"
  network_interface {
    network    = google_compute_network.ilb_network.id
    subnetwork = google_compute_subnetwork.ilb_subnet.id
  }
  boot_disk {
    initialize_params {
      image = "debian-cloud/debian-12"
    }
  }
}

Regional internal Application Load Balancer with a MIG backend and an HTTP-to-HTTPS redirect

You can use Terraform resources to bring up an internal HTTPS load balancer with a MIG backend and an HTTP-to-HTTPS redirect.

For information about the load balancer setup, see the primary setup guide .

 # VPC network
resource "google_compute_network" "default" {
  name                    = "l7-ilb-network"
  auto_create_subnetworks = false
}

# Proxy-only subnet
resource "google_compute_subnetwork" "proxy_subnet" {
  name          = "l7-ilb-proxy-subnet"
  ip_cidr_range = "10.0.0.0/24"
  region        = "europe-west1"
  purpose       = "REGIONAL_MANAGED_PROXY"
  role          = "ACTIVE"
  network       = google_compute_network.default.id
}

# Backend subnet
resource "google_compute_subnetwork" "default" {
  name          = "l7-ilb-subnet"
  ip_cidr_range = "10.0.1.0/24"
  region        = "europe-west1"
  network       = google_compute_network.default.id
}

# Reserved internal address
resource "google_compute_address" "default" {
  name         = "l7-ilb-ip"
  provider     = google-beta
  subnetwork   = google_compute_subnetwork.default.id
  address_type = "INTERNAL"
  address      = "10.0.1.5"
  region       = "europe-west1"
  purpose      = "SHARED_LOADBALANCER_VIP"
}

# Regional forwarding rule
resource "google_compute_forwarding_rule" "default" {
  name                  = "l7-ilb-forwarding-rule"
  region                = "europe-west1"
  depends_on            = [google_compute_subnetwork.proxy_subnet]
  ip_protocol           = "TCP"
  ip_address            = google_compute_address.default.id
  load_balancing_scheme = "INTERNAL_MANAGED"
  port_range            = "443"
  target                = google_compute_region_target_https_proxy.default.id
  network               = google_compute_network.default.id
  subnetwork            = google_compute_subnetwork.default.id
  network_tier          = "PREMIUM"
}

# Self-signed regional SSL certificate for testing
resource "tls_private_key" "default" {
  algorithm = "RSA"
  rsa_bits  = 2048
}

resource "tls_self_signed_cert" "default" {
  private_key_pem = tls_private_key.default.private_key_pem

  # Certificate expires after 12 hours.
  validity_period_hours = 12

  # Generate a new certificate if Terraform is run within three
  # hours of the certificate's expiration time.
  early_renewal_hours = 3

  # Reasonable set of uses for a server SSL certificate.
  allowed_uses = [
    "key_encipherment",
    "digital_signature",
    "server_auth",
  ]

  dns_names = ["example.com"]

  subject {
    common_name  = "example.com"
    organization = "ACME Examples, Inc"
  }
}

resource "google_compute_region_ssl_certificate" "default" {
  name_prefix = "my-certificate-"
  private_key = tls_private_key.default.private_key_pem
  certificate = tls_self_signed_cert.default.cert_pem
  region      = "europe-west1"
  lifecycle {
    create_before_destroy = true
  }
}

# Regional target HTTPS proxy
resource "google_compute_region_target_https_proxy" "default" {
  name             = "l7-ilb-target-https-proxy"
  region           = "europe-west1"
  url_map          = google_compute_region_url_map.https_lb.id
  ssl_certificates = [google_compute_region_ssl_certificate.default.self_link]
}

# Regional URL map
resource "google_compute_region_url_map" "https_lb" {
  name            = "l7-ilb-regional-url-map"
  region          = "europe-west1"
  default_service = google_compute_region_backend_service.default.id
}

# Regional backend service
resource "google_compute_region_backend_service" "default" {
  name                  = "l7-ilb-backend-service"
  region                = "europe-west1"
  protocol              = "HTTP"
  port_name             = "http-server"
  load_balancing_scheme = "INTERNAL_MANAGED"
  timeout_sec           = 10
  health_checks         = [google_compute_region_health_check.default.id]
  backend {
    group           = google_compute_region_instance_group_manager.default.instance_group
    balancing_mode  = "UTILIZATION"
    capacity_scaler = 1.0
  }
}

# Instance template
resource "google_compute_instance_template" "default" {
  name         = "l7-ilb-mig-template"
  machine_type = "e2-small"
  tags         = ["http-server"]
  network_interface {
    network    = google_compute_network.default.id
    subnetwork = google_compute_subnetwork.default.id
    access_config {
      # add external ip to fetch packages
    }
  }
  disk {
    source_image = "debian-cloud/debian-12"
    auto_delete  = true
    boot         = true
  }

  # install nginx and serve a simple web page
  metadata = {
    startup-script = <<-EOF1
      #! /bin/bash
      set -euo pipefail

      export DEBIAN_FRONTEND=noninteractive
      apt-get update
      apt-get install -y nginx-light jq

      NAME=$(curl -H "Metadata-Flavor: Google" "http://metadata.google.internal/computeMetadata/v1/instance/hostname")
      IP=$(curl -H "Metadata-Flavor: Google" "http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/ip")
      METADATA=$(curl -f -H "Metadata-Flavor: Google" "http://metadata.google.internal/computeMetadata/v1/instance/attributes/?recursive=True" | jq 'del(.["startup-script"])')

      cat <<EOF > /var/www/html/index.html
      <pre>
      Name: $NAME
      IP: $IP
      Metadata: $METADATA
      </pre>
      EOF
    EOF1
  }
  lifecycle {
    create_before_destroy = true
  }
}

# Regional health check
resource "google_compute_region_health_check" "default" {
  name   = "l7-ilb-hc"
  region = "europe-west1"
  http_health_check {
    port_specification = "USE_SERVING_PORT"
  }
}

# Regional MIG
resource "google_compute_region_instance_group_manager" "default" {
  name   = "l7-ilb-mig1"
  region = "europe-west1"
  version {
    instance_template = google_compute_instance_template.default.id
    name              = "primary"
  }
  named_port {
    name = "http-server"
    port = 80
  }
  base_instance_name = "vm"
  target_size        = 2
}

# Allow all access to health check ranges
resource "google_compute_firewall" "default" {
  name          = "l7-ilb-fw-allow-hc"
  direction     = "INGRESS"
  network       = google_compute_network.default.id
  source_ranges = ["130.211.0.0/22", "35.191.0.0/16", "35.235.240.0/20"]
  allow {
    protocol = "tcp"
  }
}

# Allow http from proxy subnet to backends
resource "google_compute_firewall" "backends" {
  name          = "l7-ilb-fw-allow-ilb-to-backends"
  direction     = "INGRESS"
  network       = google_compute_network.default.id
  source_ranges = ["10.0.0.0/24"]
  target_tags   = ["http-server"]
  allow {
    protocol = "tcp"
    ports    = ["80", "443", "8080"]
  }
}

# Test instance
resource "google_compute_instance" "default" {
  name         = "l7-ilb-test-vm"
  zone         = "europe-west1-b"
  machine_type = "e2-small"
  network_interface {
    network    = google_compute_network.default.id
    subnetwork = google_compute_subnetwork.default.id
  }
  boot_disk {
    initialize_params {
      image = "debian-cloud/debian-12"
    }
  }
}

### HTTP-to-HTTPS redirect ###

# Regional forwarding rule
resource "google_compute_forwarding_rule" "redirect" {
  name                  = "l7-ilb-redirect"
  region                = "europe-west1"
  ip_protocol           = "TCP"
  ip_address            = google_compute_address.default.id # Same as HTTPS load balancer
  load_balancing_scheme = "INTERNAL_MANAGED"
  port_range            = "80"
  target                = google_compute_region_target_http_proxy.default.id
  network               = google_compute_network.default.id
  subnetwork            = google_compute_subnetwork.default.id
  network_tier          = "PREMIUM"
}

# Regional HTTP proxy
resource "google_compute_region_target_http_proxy" "default" {
  name    = "l7-ilb-target-http-proxy"
  region  = "europe-west1"
  url_map = google_compute_region_url_map.redirect.id
}

# Regional URL map
resource "google_compute_region_url_map" "redirect" {
  name            = "l7-ilb-redirect-url-map"
  region          = "europe-west1"
  default_service = google_compute_region_backend_service.default.id
  host_rule {
    hosts        = ["*"]
    path_matcher = "allpaths"
  }

  path_matcher {
    name            = "allpaths"
    default_service = google_compute_region_backend_service.default.id
    path_rule {
      paths = ["/"]
      url_redirect {
        https_redirect         = true
        host_redirect          = "10.0.1.5:443"
        redirect_response_code = "PERMANENT_REDIRECT"
        strip_query            = true
      }
    }
  }
}

Regional internal Application Load Balancer that uses Shared VPC and a cross-project backend service

You can use Terraform resources to bring up a regional internal Application Load Balancer that uses Shared VPC and a cross-project backend service. The following architecture diagram shows where the load balancer components are created.

Load balancer frontend and backend in different service projects.
Figure 1. Load balancer frontend and backend in different service projects.

Before you start setting up a regional internal Application Load Balancer that uses Shared VPC, ensure that you have the required IAM permissions on the host and service projects . For more detailed information about the load balancer setup, see the primary setup guide .

 # VPC network
resource "google_compute_network" "default" {
  name                    = "l7-ilb-network"
  auto_create_subnetworks = false
  project                 = "my-host-project"
}

# proxy-only subnet
# https://cloud.google.com/load-balancing/docs/proxy-only-subnets#proxy_only_subnet_create
resource "google_compute_subnetwork" "proxy_subnet" {
  name          = "l7-ilb-proxy-subnet"
  ip_cidr_range = "10.0.0.0/24"
  region        = "us-central1"
  purpose       = "REGIONAL_MANAGED_PROXY"
  role          = "ACTIVE"
  network       = google_compute_network.default.id
  project       = "my-host-project"
}

# backend subnet
resource "google_compute_subnetwork" "ilb_subnet" {
  name          = "l7-ilb-subnet"
  ip_cidr_range = "10.0.1.0/24"
  region        = "us-central1"
  network       = google_compute_network.default.id
  project       = "my-host-project"
}

# allow all access from IAP and health check ranges
resource "google_compute_firewall" "fw_iap" {
  project       = "my-host-project"
  name          = "l7-ilb-fw-allow-iap-hc"
  direction     = "INGRESS"
  network       = google_compute_network.default.id
  source_ranges = ["130.211.0.0/22", "35.191.0.0/16", "35.235.240.0/20"]
  allow {
    protocol = "tcp"
  }
}

# allow http from proxy subnet to backends
resource "google_compute_firewall" "fw_ilb_to_backends" {
  project       = "my-host-project"
  name          = "l7-ilb-fw-allow-ilb-to-backends"
  direction     = "INGRESS"
  network       = google_compute_network.default.id
  source_ranges = ["0.0.0.0/0"]
  target_tags   = ["http-server"]
  allow {
    protocol = "tcp"
    ports    = ["80", "443", "8080"]
  }
}

# forwarding rule
resource "google_compute_forwarding_rule" "default" {
  name                  = "l7-ilb-forwarding-rule"
  region                = "us-central1"
  ip_protocol           = "TCP"
  load_balancing_scheme = "INTERNAL_MANAGED"
  port_range            = "80"
  target                = google_compute_region_target_http_proxy.default.id
  network               = google_compute_network.default.id
  subnetwork            = google_compute_subnetwork.ilb_subnet.id
  network_tier          = "PREMIUM"
  project               = "my-service-project-01"
  depends_on            = [google_compute_subnetwork.proxy_subnet]
}

# HTTP target proxy
resource "google_compute_region_target_http_proxy" "default" {
  name    = "l7-ilb-target-http-proxy"
  region  = "us-central1"
  url_map = google_compute_region_url_map.default.id
  project = "my-service-project-01"
}

# URL map
resource "google_compute_region_url_map" "default" {
  name            = "l7-ilb-regional-url-map"
  region          = "us-central1"
  default_service = google_compute_region_backend_service.default.id
  project         = "my-service-project-01"
}

# regional health check
resource "google_compute_region_health_check" "default" {
  project = "my-service-project-02"
  name    = "l7-ilb-rhc"
  region  = "us-central1"
  http_health_check {
    port_specification = "USE_SERVING_PORT"
  }
}

# regional backend service
resource "google_compute_region_backend_service" "default" {
  project               = "my-service-project-02"
  name                  = "l7-ilb-backend-service"
  region                = "us-central1"
  protocol              = "HTTP"
  load_balancing_scheme = "INTERNAL_MANAGED"
  timeout_sec           = 10
  health_checks         = [google_compute_region_health_check.default.id]
  backend {
    group           = google_compute_region_instance_group_manager.default.instance_group
    balancing_mode  = "UTILIZATION"
    capacity_scaler = 1.0
  }
}

# health check
resource "google_compute_health_check" "default" {
  project            = "my-service-project-02"
  name               = "l7-ilb-hc"
  timeout_sec        = 1
  check_interval_sec = 1
  tcp_health_check {
    port = "80"
  }
}

# instance template
resource "google_compute_instance_template" "default" {
  project      = "my-service-project-02"
  name         = "l7-ilb-mig-template"
  machine_type = "e2-small"
  tags         = ["http-server"]

  network_interface {
    network    = google_compute_network.default.id
    subnetwork = google_compute_subnetwork.ilb_subnet.id
    access_config {
      # add external ip to fetch packages
    }
  }
  disk {
    source_image = "debian-cloud/debian-12"
    auto_delete  = true
    boot         = true
  }

  # install nginx and serve a simple web page
  metadata = {
    startup-script = <<-EOF1
      #! /bin/bash
      set -euo pipefail

      export DEBIAN_FRONTEND=noninteractive
      apt-get update
      apt-get install -y nginx-light jq

      NAME=$(curl -H "Metadata-Flavor: Google" "http://metadata.google.internal/computeMetadata/v1/instance/hostname")
      IP=$(curl -H "Metadata-Flavor: Google" "http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/ip")
      METADATA=$(curl -f -H "Metadata-Flavor: Google" "http://metadata.google.internal/computeMetadata/v1/instance/attributes/?recursive=True" | jq 'del(.["startup-script"])')

      cat <<EOF > /var/www/html/index.html
      <pre>
      Name: $NAME
      IP: $IP
      Metadata: $METADATA
      </pre>
      EOF
    EOF1
  }
}

# MIG
resource "google_compute_region_instance_group_manager" "default" {
  project = "my-service-project-02"
  name    = "l7-ilb-mig1"
  region  = "us-central1"
  version {
    instance_template = google_compute_instance_template.default.id
    name              = "primary"
  }
  base_instance_name = "vm"
  target_size        = 2
  auto_healing_policies {
    health_check      = google_compute_health_check.default.id
    initial_delay_sec = 300
  }
  depends_on = [google_project_iam_binding.default]
}

data "google_project" "service_project02" {
  project_id = "my-service-project-02"
}

# IAM Role
resource "google_project_iam_binding" "default" {
  project = "my-host-project"
  role    = "roles/compute.networkUser"

  members = [
    "serviceAccount:${data.google_project.service_project02.number}@cloudservices.gserviceaccount.com",
  ]
}

# test instance
resource "google_compute_instance" "test_vm" {
  project      = "my-service-project-02"
  name         = "l7-ilb-test-vm"
  zone         = "us-central1-b"
  machine_type = "e2-small"
  network_interface {
    network    = google_compute_network.default.id
    subnetwork = google_compute_subnetwork.ilb_subnet.id
  }
  boot_disk {
    initialize_params {
      image = "debian-cloud/debian-12"
    }
  }
  lifecycle {
    ignore_changes = [
      metadata["ssh-keys"]
    ]
  }
  depends_on = [google_project_iam_binding.default]
}