Add VPN gateway data source (hashicorp#1071)

Author: jphalip

Diff for: docs/d/datasource_compute_vpn_gateway.html.markdown

@@ -0,0 +1,46 @@
+---
+layout: "google"
+page_title: "Google: google_compute_vpn_gateway"
+sidebar_current: "docs-google-datasource-compute-vpn-gateway"
+description: |-
+  Get a VPN gateway within GCE.
+---
+
+# google\_compute\_vpn\_gateway
+
+Get a VPN gateway within GCE from its name.
+
+## Example Usage
+
+```tf
+data "google_compute_vpn_gateway" "my-vpn-gateway" {
+  name = "vpn-gateway-us-east1"
+}
+```
+
+## Argument Reference
+
+The following arguments are supported:
+
+* `name` - (Required) The name of the VPN gateway.
+
+
+- - -
+
+* `project` - (Optional) The project in which the resource belongs. If it
+    is not provided, the provider project is used.
+
+* `region` - (Optional) The region in which the resource belongs. If it
+    is not provided, the project region is used.
+
+## Attributes Reference
+
+In addition to the arguments listed above, the following attributes are exported:
+
+* `network` - The network of this VPN gateway.
+
+* `description` - Description of this VPN gateway.
+
+* `region` - Region of this VPN gateway.
+
+* `self_link` - The URI of the resource.

Diff for: google.erb

@@ -37,6 +37,9 @@
       <li<%= sidebar_current("docs-google-datasource-compute-subnetwork") %>>
         <a href="/docs/providers/google/d/datasource_compute_subnetwork.html">google_compute_subnetwork</a>
       </li>
+      <li<%= sidebar_current("docs-google-datasource-compute-vpn-gateway") %>>
+        <a href="/docs/providers/google/d/datasource_compute_vpn_gateway.html">google_compute_vpn_gateway</a>
+      </li>
       <li<%= sidebar_current("docs-google-datasource-compute-zones") %>>
       <a href="/docs/providers/google/d/google_compute_zones.html">google_compute_zones</a>
       </li>