DRY it out, and reverse fix for hashicorp#5552.

builtin/providers/google/provider.go

@@ -223,3 +223,53 @@ func getZonalResourceFromRegion(getResource func(string) (interface{}, error), r
 	// Resource does not exist in this region
 	return nil, nil
 }
+
+// getNetworkLink reads the "network" field from the given resource data and if the value:
+// - is a resource URL, returns the string unchanged
+// - is the network name only, then looks up the resource URL using the google client
+func getNetworkLink(d *schema.ResourceData, config *Config, field string) (string, error) {
+	if v, ok := d.GetOk(field); ok {
+		network := v.(string)
+
+		project, err := getProject(d, config)
+		if err != nil {
+			return "", err
+		}
+
+		if !strings.HasPrefix(network, "https://www.googleapis.com/compute/") {
+			// Network value provided is just the name, lookup the network SelfLink
+			networkData, err := config.clientCompute.Networks.Get(
+				project, network).Do()
+			if err != nil {
+				return "", fmt.Errorf("Error reading network: %s", err)
+			}
+			network = networkData.SelfLink
+		}
+
+		return network, nil
+
+	} else {
+		return "", nil
+	}
+}
+
+// getNetworkName reads the "network" field from the given resource data and if the value:
+// - is a resource URL, extracts the network name from the URL and returns it
+// - is the network name only (i.e not prefixed with http://www.googleapis.com/compute/...), is returned unchanged
+func getNetworkName(d *schema.ResourceData, field string) (string, error) {
+	if v, ok := d.GetOk(field); ok {
+		network := v.(string)
+
+		if strings.HasPrefix(network, "https://www.googleapis.com/compute/") {
+			// extract the network name from SelfLink URL
+			networkName := network[strings.LastIndex(network, "/")+1:]
+			if networkName == "" {
+				return "", fmt.Errorf("network url not valid")
+			}
+			return networkName, nil
+		}
+
+		return network, nil
+	}
+	return "", nil
+}

builtin/providers/google/resource_compute_instance.go

@@ -478,14 +478,13 @@ func resourceComputeInstanceCreate(d *schema.ResourceData, meta interface{}) err
 			if networkName != "" && subnetworkName != "" {
 				return fmt.Errorf("Cannot specify both network and subnetwork values.")
 			} else if networkName != "" {
-				network, err := config.clientCompute.Networks.Get(
-					project, networkName).Do()
+				networkLink, err = getNetworkLink(d, config, prefix+".network")
 				if err != nil {
 					return fmt.Errorf(
 						"Error referencing network '%s': %s",
 						networkName, err)
 				}
-				networkLink = network.SelfLink
+
 			} else {
 				region := getRegionFromZone(d.Get("zone").(string))
 				subnetwork, err := config.clientCompute.Subnetworks.Get(

builtin/providers/google/resource_compute_instance_template.go

@@ -417,13 +417,12 @@ func buildNetworks(d *schema.ResourceData, meta interface{}) ([]*compute.Network
 
 		var networkLink, subnetworkLink string
 		if networkName != "" {
-			network, err := config.clientCompute.Networks.Get(
-				project, networkName).Do()
+			networkLink, err = getNetworkLink(d, config, prefix+".network")
 			if err != nil {
 				return nil, fmt.Errorf("Error referencing network '%s': %s",
 					networkName, err)
 			}
-			networkLink = network.SelfLink
+
 		} else {
 			// lookup subnetwork link using region and subnetwork name
 			region, err := getRegion(d, config)

builtin/providers/google/resource_compute_route.go

@@ -106,8 +106,7 @@ func resourceComputeRouteCreate(d *schema.ResourceData, meta interface{}) error
 	}
 
 	// Look up the network to attach the route to
-	network, err := config.clientCompute.Networks.Get(
-		project, d.Get("network").(string)).Do()
+	network, err := getNetworkLink(d, config, "network")
 	if err != nil {
 		return fmt.Errorf("Error reading network: %s", err)
 	}
@@ -149,7 +148,7 @@ func resourceComputeRouteCreate(d *schema.ResourceData, meta interface{}) error
 	route := &compute.Route{
 		Name:             d.Get("name").(string),
 		DestRange:        d.Get("dest_range").(string),
-		Network:          network.SelfLink,
+		Network:          network,
 		NextHopInstance:  nextHopInstance,
 		NextHopVpnTunnel: nextHopVpnTunnel,
 		NextHopIp:        nextHopIp,

builtin/providers/google/resource_compute_subnetwork.go

@@ -91,16 +91,9 @@ func resourceComputeSubnetworkCreate(d *schema.ResourceData, meta interface{}) e
 		return err
 	}
 
-	// Network can be provided as just the name, or the full resource URL
-	network := d.Get("network").(string)
-	if !strings.HasPrefix(network, "https://www.googleapis.com/compute/") {
-		// Network value provided is just the name, lookup the network URL
-		networkData, err := config.clientCompute.Networks.Get(
-			project, d.Get("network").(string)).Do()
-		if err != nil {
-			return fmt.Errorf("Error reading network: %s", err)
-		}
-		network = networkData.SelfLink
+	network, err := getNetworkLink(d, config, "network")
+	if err != nil {
+		return err
 	}
 
 	// Build the subnetwork parameters

builtin/providers/google/resource_compute_vpn_gateway.go

@@ -8,7 +8,6 @@ import (
 
 	"google.golang.org/api/compute/v1"
 	"google.golang.org/api/googleapi"
-	"strings"
 )
 
 func resourceComputeVpnGateway() *schema.Resource {
@@ -72,16 +71,9 @@ func resourceComputeVpnGatewayCreate(d *schema.ResourceData, meta interface{}) e
 	}
 
 	name := d.Get("name").(string)
-	network := d.Get("network").(string)
-
-	if !strings.HasPrefix(network, "https://www.googleapis.com/compute/") {
-		// Network value provided is just the name, lookup the network URL
-		networkData, err := config.clientCompute.Networks.Get(
-			project, d.Get("network").(string)).Do()
-		if err != nil {
-			return fmt.Errorf("Error reading network: %s", err)
-		}
-		network = networkData.SelfLink
+	network, err := getNetworkLink(d, config, "network")
+	if err != nil {
+		return err
 	}
 
 	vpnGatewaysService := compute.NewTargetVpnGatewaysService(config.clientCompute)

builtin/providers/google/resource_container_cluster.go

@@ -289,8 +289,12 @@ func resourceContainerClusterCreate(d *schema.ResourceData, meta interface{}) er
 		cluster.MonitoringService = v.(string)
 	}
 
-	if v, ok := d.GetOk("network"); ok {
-		cluster.Network = v.(string)
+	if _, ok := d.GetOk("network"); ok {
+		network, err := getNetworkName(d, "network")
+		if err != nil {
+			return err
+		}
+		cluster.Network = network
 	}
 
 	if v, ok := d.GetOk("subnetwork"); ok {
@@ -425,7 +429,7 @@ func resourceContainerClusterRead(d *schema.ResourceData, meta interface{}) erro
 	d.Set("description", cluster.Description)
 	d.Set("logging_service", cluster.LoggingService)
 	d.Set("monitoring_service", cluster.MonitoringService)
-	d.Set("network", cluster.Network)
+	d.Set("network", d.Get("network").(string))
 	d.Set("subnetwork", cluster.Subnetwork)
 	d.Set("node_config", flattenClusterNodeConfig(cluster.NodeConfig))
 	d.Set("instance_group_urls", cluster.InstanceGroupUrls)

builtin/providers/google/resource_container_cluster_test.go

@@ -43,6 +43,25 @@ func TestAccContainerCluster_withNodeConfig(t *testing.T) {
 	})
 }
 
+func TestAccContainerCluster_network(t *testing.T) {
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckContainerClusterDestroy,
+		Steps: []resource.TestStep{
+			resource.TestStep{
+				Config: testAccContainerCluster_networkRef,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckContainerClusterExists(
+						"google_container_cluster.with_net_ref_by_url"),
+					testAccCheckContainerClusterExists(
+						"google_container_cluster.with_net_ref_by_name"),
+				),
+			},
+		},
+	})
+}
+
 func testAccCheckContainerClusterDestroy(s *terraform.State) error {
 	config := testAccProvider.Meta().(*Config)
 
@@ -124,3 +143,35 @@ resource "google_container_cluster" "with_node_config" {
 		]
 	}
 }`, acctest.RandString(10))
+
+var testAccContainerCluster_networkRef = fmt.Sprintf(`
+resource "google_compute_network" "container_network" {
+	name = "container-net-%s"
+	auto_create_subnetworks = true
+}
+
+resource "google_container_cluster" "with_net_ref_by_url" {
+	name = "cluster-test-%s"
+	zone = "us-central1-a"
+	initial_node_count = 1
+
+	master_auth {
+		username = "mr.yoda"
+		password = "adoy.rm"
+	}
+
+	network = "${google_compute_network.container_network.self_link}"
+}
+
+resource "google_container_cluster" "with_net_ref_by_name" {
+	name = "cluster-test-%s"
+	zone = "us-central1-a"
+	initial_node_count = 1
+
+	master_auth {
+		username = "mr.yoda"
+		password = "adoy.rm"
+	}
+
+	network = "${google_compute_network.container_network.name}"
+}`, acctest.RandString(10), acctest.RandString(10), acctest.RandString(10))

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

@@ -133,7 +133,7 @@ the type is "local-ssd", in which case scratch must be true).
 
 The `network_interface` block supports:
 
-* `network` - (Optional) The name of the network to attach this interface to.
+* `network` - (Optional) The name or self_link of the network to attach this interface to.
     Either `network` or `subnetwork` must be provided.
 
 *  `subnetwork` - (Optional) the name of the subnetwork to attach this interface

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

@@ -192,7 +192,7 @@ The `disk` block supports:
 
 The `network_interface` block supports:
 
-* `network` - (Optional) The name of the network to attach this interface to.
+* `network` - (Optional) The name or self_link of the network to attach this interface to.
     Use `network` attribute for Legacy or Auto subnetted networks and
     `subnetwork` for custom subnetted networks.
 

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

@@ -37,7 +37,7 @@ The following arguments are supported:
 * `name` - (Required) A unique name for the resource, required by GCE.
     Changing this forces a new resource to be created.
 
-* `network` - (Required) The name of the network to attach this route to.
+* `network` - (Required) The name or self_link of the network to attach this route to.
 
 * `priority` - (Required) The priority of this route, used to break ties.
 

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

@@ -66,7 +66,7 @@ resource "google_container_cluster" "primary" {
     `monitoring.googleapis.com` and `none`. Defaults to
     `monitoring.googleapis.com`
 
-* `network` - (Optional) The name of the Google Compute Engine network to which
+* `network` - (Optional) The name or self_link of the Google Compute Engine network to which
     the cluster is connected
 
 * `node_config` -  (Optional) The machine type and image to use for all nodes in