r/vmfs_datastore: Fix some error strings, refine retry waiter

Some error string cleanup, and also an update to the delete retry
waiter so that it handles the actual ResourceInUse error instead of
doing a string match.

vsphere/resource_vsphere_vmfs_datastore.go

@@ -3,7 +3,6 @@ package vsphere
 import (
 	"context"
 	"fmt"
-	"regexp"
 	"time"
 
 	"github.com/hashicorp/terraform/helper/resource"
@@ -26,7 +25,7 @@ const (
 // creation where rollback is not possible.
 const formatCreateRollbackErrorUpdate = `
 WARNING: Dangling resource!
-There was an error extending your datastore with disk: %s:
+There was an error extending your datastore with disk: %q:
 %s
 Additionally, there was an error removing the created datastore:
 %s
@@ -49,12 +48,13 @@ You will need to remove this datastore manually before trying again.
 // will require repair of the state before TF can continue.
 const formatUpdateInconsistentState = `
 WARNING: Inconsistent state!
-Terraform was able to add disk %s, but could not save the update to the state.
+Terraform was able to add disk %q, but could not save the update to the state.
 The error was:
 %s
 This is more than likely a bug. Please report it at:
 https://github.com/terraform-providers/terraform-provider-vsphere/issues
-You will also need to repair your state before trying again.
+Also, please try running "terraform refresh" to try to update the state before
+trying again. If this fails, you may need to repair the state manually.
 `
 
 func resourceVSphereVmfsDatastore() *schema.Resource {
@@ -123,7 +123,7 @@ func resourceVSphereVmfsDatastoreCreate(d *schema.ResourceData, meta interface{}
 				// manually.
 				return fmt.Errorf(formatCreateRollbackErrorUpdate, disk, err, remErr)
 			}
-			return fmt.Errorf("error fetching datastore extend spec for disk %s: %s", disk, err)
+			return fmt.Errorf("error fetching datastore extend spec for disk %q: %s", disk, err)
 		}
 		ctx, cancel := context.WithTimeout(context.Background(), defaultAPITimeout)
 		defer cancel()
@@ -134,7 +134,7 @@ func resourceVSphereVmfsDatastoreCreate(d *schema.ResourceData, meta interface{}
 				// manually.
 				return fmt.Errorf(formatCreateRollbackErrorUpdate, disk, err, remErr)
 			}
-			return fmt.Errorf("error extending datastore with disk %s: %s", disk, err)
+			return fmt.Errorf("error extending datastore with disk %q: %s", disk, err)
 		}
 	}
 
@@ -270,7 +270,7 @@ func resourceVSphereVmfsDatastoreDelete(d *schema.ResourceData, meta interface{}
 	deleteRetryFunc := func() (interface{}, string, error) {
 		err := removeDatastore(dss, ds)
 		if err != nil {
-			if matched, _ := regexp.MatchString("The resource.*is in use", err.Error()); matched {
+			if isResourceInUseError(err) {
 				// Pending
 				return struct{}{}, retryDeletePending, nil
 			}

vsphere/vim_helper.go

@@ -40,6 +40,17 @@ func isManagedObjectNotFoundError(err error) bool {
 	return false
 }
 
+// isResourceInUseError checks an error to see if it's of the
+// ResourceInUse type.
+func isResourceInUseError(err error) bool {
+	if f, ok := vimSoapFault(err); ok {
+		if _, ok := f.(types.ResourceInUse); ok {
+			return true
+		}
+	}
+	return false
+}
+
 // renameObject renames a MO and tracks the task to make sure it completes.
 func renameObject(client *govmomi.Client, ref types.ManagedObjectReference, new string) error {
 	req := types.Rename_Task{