Support IP forwarding on GCE instances

This change exposes the CanIpForward property of the Instance, allowing
users to create instances that are allowed to function as NAT or VPN
gateways.

builtin/providers/google/resource_compute_instance.go

@@ -97,6 +97,13 @@ func resourceComputeInstance() *schema.Resource {
 				},
 			},
 
+			"can_ip_forward": &schema.Schema{
+				Type:     schema.TypeBool,
+				Optional: true,
+				Default:  false,
+				ForceNew: true,
+			},
+
 			"metadata": &schema.Schema{
 				Type:     schema.TypeList,
 				Optional: true,
@@ -230,6 +237,7 @@ func resourceComputeInstanceCreate(d *schema.ResourceData, meta interface{}) err
 
 	// Create the instance information
 	instance := compute.Instance{
+		CanIpForward:      d.Get("can_ip_forward").(bool),
 		Description:       d.Get("description").(string),
 		Disks:             disks,
 		MachineType:       machineType.SelfLink,
@@ -305,6 +313,8 @@ func resourceComputeInstanceRead(d *schema.ResourceData, meta interface{}) error
 		return fmt.Errorf("Error reading instance: %s", err)
 	}
 
+	d.Set("can_ip_forward", instance.CanIpForward)
+
 	// Set the networks
 	for i, iface := range instance.NetworkInterfaces {
 		prefix := fmt.Sprintf("network.%d", i)

builtin/providers/google/resource_compute_instance_test.go

@@ -225,6 +225,7 @@ resource "google_compute_instance" "foobar" {
 	name = "terraform-test"
 	machine_type = "n1-standard-1"
 	zone = "us-central1-a"
+	can_ip_forward = false
 	tags = ["foo", "bar"]
 
 	disk {

website/source/docs/providers/google/r/compute_instance.html.markdown

@@ -47,6 +47,10 @@ The following arguments are supported:
 * `disk` - (Required) Disks to attach to the instance. This can be specified
     multiple times for multiple disks. Structure is documented below.
 
+* `can_ip_forward` - (Optional) Whether to allow sending and receiving of
+    packets with non-matching source or destination IPs.
+    This defaults to false.
+
 * `metadata` - (Optional) Metadata key/value pairs to make available from
     within the instance.