Add data source for forwarding rule (hashicorp#1078)

Author: jphalip

docs/d/datasource_compute_forwarding_rule.html.markdown

@@ -0,0 +1,62 @@
+---
+layout: "google"
+page_title: "Google: google_compute_forwarding_rule"
+sidebar_current: "docs-google-datasource-compute-forwarding-rule"
+description: |-
+  Get a forwarding rule within GCE.
+---
+
+# google\_compute\_forwarding\_rule
+
+Get a forwarding rule within GCE from its name.
+
+## Example Usage
+
+```tf
+data "google_compute_forwarding_rule" "my-forwarding-rule" {
+  name = "forwarding-rule-us-east1"
+}
+```
+
+## Argument Reference
+
+The following arguments are supported:
+
+* `name` - (Required) The name of the forwarding rule.
+
+
+- - -
+
+* `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:
+
+* `description` - Description of this forwarding rule.
+
+* `network` - Network of this forwarding rule.
+
+* `subnetwork` - Subnetwork of this forwarding rule.
+
+* `ip_address` - IP address of this forwarding rule.
+
+* `ip_protocol` - IP protocol of this forwarding rule.
+
+* `ports` - List of ports to use for internal load balancing, if this forwarding rule has any.
+
+* `port_range` - Port range, if this forwarding rule has one.
+
+* `target` - URL of the target pool, if this forwarding rule has one.
+
+* `backend_service` - Backend service, if this forwarding rule has one.
+
+* `load_balancing_scheme` - Type of load balancing of this forwarding rule.
+
+* `region` - Region of this forwarding rule.
+
+* `self_link` - The URI of the resource.

google.erb

@@ -28,6 +28,9 @@
       <li<%= sidebar_current("docs-google-datasource-compute-image") %>>
         <a href="/docs/providers/google/d/datasource_compute_image.html">google_compute_image</a>
       </li>
+      <li<%= sidebar_current("docs-google-datasource-compute-forwarding-rule") %>>
+        <a href="/docs/providers/google/d/datasource_compute_forwarding_rule.html">google_compute_forwarding_rule</a>
+      </li>
       <li<%= sidebar_current("docs-google-datasource-compute-global-address") %>>
         <a href="/docs/providers/google/d/datasource_compute_global_address.html">google_compute_global_address</a>
       </li>