# VLAN Attachment module
This module allows for the provisioning of [HA VPN over Interconnect](https://cloud.google.com/network-connectivity/docs/interconnect/concepts/ha-vpn-interconnect?hl=it). Specifically, this module creates a VPN gateway, a configurable number of tunnels, and all the resources required to established IPSec and BGP with the peer routers.
The required pair of encrypted VLAN Attachments can be created leveraging the [net-vlan-attachment](../net-vlan-attachment/) module, as shown in the [IoIC Blueprint](../../blueprints/networking/ha-vpn-over-interconnect/).
## Examples
### Single region setup
```hcl
resource "google_compute_router" "encrypted-interconnect-overlay-router" {
name = "encrypted-interconnect-overlay-router"
project = "myproject"
network = "mynet"
region = "europe-west8"
bgp {
asn = 64514
advertise_mode = "CUSTOM"
advertised_groups = ["ALL_SUBNETS"]
advertised_ip_ranges {
range = "10.255.255.0/24"
}
advertised_ip_ranges {
range = "192.168.255.0/24"
}
}
}
resource "google_compute_external_vpn_gateway" "default" {
name = "peer-vpn-gateway"
project = "myproject"
description = "Peer IPSec over Interconnect VPN gateway"
redundancy_type = "TWO_IPS_REDUNDANCY"
interface {
id = 0
ip_address = "10.0.0.1"
}
interface {
id = 1
ip_address = "10.0.0.2"
}
}
module "vpngw-a" {
source = "./fabric/modules/net-ipsec-over-interconnect"
project_id = "myproject"
network = "mynet"
region = "europe-west8"
name = "vpngw-a"
interconnect_attachments = {
a = "attach-01"
b = "attach-02"
}
peer_gateway_config = {
create = false
id = google_compute_external_vpn_gateway.default.id
}
router_config = {
create = false
name = google_compute_router.encrypted-interconnect-overlay-router.id
}
tunnels = {
remote-0 = {
bgp_peer = {
address = "169.254.1.2"
asn = 64514
}
bgp_session_range = "169.254.1.1/30"
shared_secret = "foobar"
vpn_gateway_interface = 0
}
remote-1 = {
bgp_peer = {
address = "169.254.1.6"
asn = 64514
}
bgp_session_range = "169.254.1.5/30"
shared_secret = "foobar"
vpn_gateway_interface = 1
}
remote-2 = {
bgp_peer = {
address = "169.254.1.10"
asn = 64514
}
bgp_session_range = "169.254.1.9/30"
shared_secret = "foobar"
vpn_gateway_interface = 0
}
remote-3 = {
bgp_peer = {
address = "169.254.1.14"
asn = 64514
}
bgp_session_range = "169.254.1.13/30"
shared_secret = "foobar"
vpn_gateway_interface = 1
}
}
}
# tftest modules=1 resources=16
```
## Variables
| name | description | type | required | default |
|---|---|:---:|:---:|:---:|
| [interconnect_attachments](variables.tf#L17) | VLAN attachments used by the VPN Gateway. | object({…})
| ✓ | |
| [name](variables.tf#L25) | Common name to identify the VPN Gateway. | string
| ✓ | |
| [network](variables.tf#L30) | The VPC name to which resources are associated to. | string
| ✓ | |
| [peer_gateway_config](variables.tf#L35) | IP addresses for the external peer gateway. | object({…})
| ✓ | |
| [project_id](variables.tf#L55) | The project id. | string
| ✓ | |
| [region](variables.tf#L60) | GCP Region. | string
| ✓ | |
| [router_config](variables.tf#L65) | Cloud Router configuration for the VPN. If you want to reuse an existing router, set create to false and use name to specify the desired router. | object({…})
| ✓ | |
| [tunnels](variables.tf#L80) | VPN tunnel configurations. | map(object({…}))
| | {}
|
## Outputs
| name | description | sensitive |
|---|---|:---:|
| [bgp_peers](outputs.tf#L18) | BGP peer resources. | |
| [external_gateway](outputs.tf#L25) | External VPN gateway resource. | |
| [id](outputs.tf#L30) | Fully qualified VPN gateway id. | |
| [random_secret](outputs.tf#L35) | Generated secret. | |
| [router](outputs.tf#L40) | Router resource (only if auto-created). | |
| [router_name](outputs.tf#L45) | Router name. | |
| [self_link](outputs.tf#L50) | HA VPN gateway self link. | |
| [tunnels](outputs.tf#L55) | VPN tunnel resources. | |