Accept subnetwork name only in forwarding rule (#1552)

* Accept subnetwork name only in forwarding rule

* Fix acceptance test

Author: rosbo

google/resource_compute_forwarding_rule.go

@@ -108,10 +108,11 @@ func resourceComputeForwardingRule() *schema.Resource {
 			},
 
 			"subnetwork": &schema.Schema{
-				Type:     schema.TypeString,
-				Optional: true,
-				ForceNew: true,
-				Computed: true,
+				Type:             schema.TypeString,
+				Optional:         true,
+				ForceNew:         true,
+				Computed:         true,
+				DiffSuppressFunc: compareSelfLinkOrResourceName,
 			},
 		},
 	}
@@ -125,6 +126,11 @@ func resourceComputeForwardingRuleCreate(d *schema.ResourceData, meta interface{
 		return err
 	}
 
+	subnetwork, err := ParseSubnetworkFieldValue(d.Get("subnetwork").(string), d, config)
+	if err != nil {
+		return err
+	}
+
 	region, err := getRegion(d, config)
 	if err != nil {
 		return err
@@ -151,7 +157,7 @@ func resourceComputeForwardingRuleCreate(d *schema.ResourceData, meta interface{
 		Network:             network.RelativeLink(),
 		PortRange:           d.Get("port_range").(string),
 		Ports:               ports,
-		Subnetwork:          d.Get("subnetwork").(string),
+		Subnetwork:          subnetwork.RelativeLink(),
 		Target:              d.Get("target").(string),
 	}
 

google/resource_compute_forwarding_rule_test.go

@@ -242,6 +242,7 @@ resource "google_compute_forwarding_rule" "foobar" {
   backend_service       = "${google_compute_region_backend_service.foobar-bs.self_link}"
   ports                 = ["80"]
   network               = "${google_compute_network.foobar.name}"
+  subnetwork            = "%s"
 }
 resource "google_compute_forwarding_rule" "foobar2" {
   description           = "Resource created for Terraform acceptance testing"
@@ -251,5 +252,5 @@ resource "google_compute_forwarding_rule" "foobar2" {
   ports                 = ["80"]
   network               = "${google_compute_network.foobar.self_link}"
 }
-`, serviceName, checkName, networkName, ruleName1, ruleName2)
+`, serviceName, checkName, networkName, ruleName1, networkName, ruleName2)
 }