google_compute_vpn_gateway

resource:
  google_compute_network:
    network1:
      name: network1
      ipv4_range: 10.120.0.0/16
  google_compute_vpn_gateway:
    target_gateway:
      name: vpn1
      network: '${google_compute_network.network1.self_link}'
      region: '${var.region}'
  google_compute_address:
    vpn_static_ip:
      name: vpn-static-ip
      region: '${var.region}'
  google_compute_forwarding_rule:
    fr_esp:
      name: fr-esp
      region: '${var.region}'
      ip_protocol: ESP
      ip_address: '${google_compute_address.vpn_static_ip.address}'
      target: '${google_compute_vpn_gateway.target_gateway.self_link}'
    fr_udp500:
      name: fr-udp500
      region: '${var.region}'
      ip_protocol: UDP
      port_range: 500
      ip_address: '${google_compute_address.vpn_static_ip.address}'
      target: '${google_compute_vpn_gateway.target_gateway.self_link}'
    fr_udp4500:
      name: fr-udp4500
      region: '${var.region}'
      ip_protocol: UDP
      port_range: 4500
      ip_address: '${google_compute_address.vpn_static_ip.address}'
      target: '${google_compute_vpn_gateway.target_gateway.self_link}'
  google_compute_vpn_tunnel:
    tunnel1:
      name: tunnel1
      region: '${var.region}'
      peer_ip: 15.0.0.120
      shared_secret: 'a secret message'
      target_vpn_gateway: '${google_compute_vpn_gateway.target_gateway.self_link}'
      depends_on:
        - google_compute_forwarding_rule.fr_esp
        - google_compute_forwarding_rule.fr_udp500
        - google_compute_forwarding_rule.fr_udp4500
  google_compute_route:
    route1:
      name: route1
      network: '${google_compute_network.network1.name}'
      dest_range: 15.0.0.0/24
      priority: 1000
      next_hop_vpn_tunnel: '${google_compute_vpn_tunnel.tunnel1.self_link}'

resource "google_compute_network" "network1" {
  name       = "network1"
  ipv4_range = "10.120.0.0/16"
}

resource "google_compute_vpn_gateway" "target_gateway" {
  name    = "vpn1"
  network = "${google_compute_network.network1.self_link}"
  region  = "${var.region}"
}

resource "google_compute_address" "vpn_static_ip" {
  name   = "vpn-static-ip"
  region = "${var.region}"
}

resource "google_compute_forwarding_rule" "fr_esp" {
  name        = "fr-esp"
  region      = "${var.region}"
  ip_protocol = "ESP"
  ip_address  = "${google_compute_address.vpn_static_ip.address}"
  target      = "${google_compute_vpn_gateway.target_gateway.self_link}"
}

resource "google_compute_forwarding_rule" "fr_udp500" {
  name        = "fr-udp500"
  region      = "${var.region}"
  ip_protocol = "UDP"
  port_range  = "500"
  ip_address  = "${google_compute_address.vpn_static_ip.address}"
  target      = "${google_compute_vpn_gateway.target_gateway.self_link}"
}

resource "google_compute_forwarding_rule" "fr_udp4500" {
  name        = "fr-udp4500"
  region      = "${var.region}"
  ip_protocol = "UDP"
  port_range  = "4500"
  ip_address  = "${google_compute_address.vpn_static_ip.address}"
  target      = "${google_compute_vpn_gateway.target_gateway.self_link}"
}

resource "google_compute_vpn_tunnel" "tunnel1" {
  name          = "tunnel1"
  region        = "${var.region}"
  peer_ip       = "15.0.0.120"
  shared_secret = "a secret message"

  target_vpn_gateway = "${google_compute_vpn_gateway.target_gateway.self_link}"

  depends_on = [
    "google_compute_forwarding_rule.fr_esp",
    "google_compute_forwarding_rule.fr_udp500",
    "google_compute_forwarding_rule.fr_udp4500",
  ]
}

resource "google_compute_route" "route1" {
  name       = "route1"
  network    = "${google_compute_network.network1.name}"
  dest_range = "15.0.0.0/24"
  priority   = 1000

  next_hop_vpn_tunnel = "${google_compute_vpn_tunnel.tunnel1.self_link}"
}