Enable use of URI for snapshot name

builtin/providers/google/resource_compute_disk.go

@@ -3,6 +3,7 @@ package google
 import (
 	"fmt"
 	"log"
+	"regexp"
 
 	"github.com/hashicorp/terraform/helper/schema"
 	"google.golang.org/api/compute/v1"
@@ -129,17 +130,21 @@ func resourceComputeDiskCreate(d *schema.ResourceData, meta interface{}) error {
 
 	if v, ok := d.GetOk("snapshot"); ok {
 		snapshotName := v.(string)
-		log.Printf("[DEBUG] Loading snapshot: %s", snapshotName)
-		snapshotData, err := config.clientCompute.Snapshots.Get(
-			project, snapshotName).Do()
-
-		if err != nil {
-			return fmt.Errorf(
-				"Error loading snapshot '%s': %s",
-				snapshotName, err)
+		match, _ := regexp.MatchString("^http", snapshotName) 
+		if match {
+		  disk.SourceSnapshot = snapshotName
+		} else {
+		  log.Printf("[DEBUG] Loading snapshot: %s", snapshotName)
+		  snapshotData, err := config.clientCompute.Snapshots.Get(
+		    project, snapshotName).Do()
+
+		  if err != nil {
+		    return fmt.Errorf(
+		      "Error loading snapshot '%s': %s",
+		      snapshotName, err)
+		  }
+		  disk.SourceSnapshot = snapshotData.SelfLink
 		}
-
-		disk.SourceSnapshot = snapshotData.SelfLink
 	}
 
 	if v, ok := d.GetOk("disk_encryption_key_raw"); ok {