Support delete and cluster_delete with many resources

Not like nova-delete when use trove-delete there is only support
delete an instance everytime. With this patch, we can delete
many instances or clusters in the same call, like
trove delete instance1 instance2.

Change-Id: I6bb0c406ba7f4c0e43cddfdff1d156b7e82ffa7a

releasenotes/notes/run-an-action-on-many-resources-41bbe191318b97dd.yaml

@@ -0,0 +1,6 @@
+---
+features:
+    - This change defines do_action_on_many function as a helper to run an
+      action on many resources (like trove delete). Use command like
+      ``trove delete instance1 instance2 ...`` to delete many instances and the
+      same as cluster-delete.

troveclient/utils.py

@@ -334,3 +334,19 @@ def do_action_with_msg(action, success_msg):
 
     action
     print(success_msg)
+
+
+def do_action_on_many(action, resources, success_msg, error_msg):
+    """Helper to run an action on many resources."""
+    failure_flag = False
+
+    for resource in resources:
+        try:
+            action(resource)
+            print(success_msg % resource)
+        except Exception as e:
+            failure_flag = True
+            print(encodeutils.safe_encode(six.text_type(e)))
+
+    if failure_flag:
+        raise exceptions.CommandError(error_msg)

troveclient/v1/shell.py

@@ -402,15 +402,16 @@ def do_cluster_shrink(cs, args):
     cs.clusters.shrink(cluster, instances=instances)
 
 
-@utils.arg('instance', metavar='<instance>',
-           help=_('ID or name of the instance.'))
+@utils.arg('instance', metavar='<instance>', nargs='+',
+           help=_('ID or name of the instance(s).'))
 @utils.service_type('database')
 def do_delete(cs, args):
-    """Deletes an instance."""
-    instance = _find_instance(cs, args.instance)
-    msg = _("Request to delete instance %s "
-            "has been accepted.") % instance.id
-    utils.do_action_with_msg(cs.instances.delete(instance), msg)
+    """Delete specified instance(s)."""
+    utils.do_action_on_many(
+        lambda s: cs.instances.delete(_find_instance(cs, s)),
+        args.instance,
+        _("Request to delete instance %s has been accepted."),
+        _("Unable to delete the specified instance(s)."))
 
 
 @utils.arg('instance', metavar='<instance>',
@@ -437,15 +438,16 @@ def do_reset_status(cs, args):
     cs.instances.reset_status(instance=instance)
 
 
-@utils.arg('cluster', metavar='<cluster>',
-           help=_('ID or name of the cluster.'))
+@utils.arg('cluster', metavar='<cluster>', nargs='+',
+           help=_('ID or name of the cluster(s).'))
 @utils.service_type('database')
 def do_cluster_delete(cs, args):
-    """Deletes a cluster."""
-    cluster = _find_cluster(cs, args.cluster)
-    msg = _("Request to delete cluster %s "
-            "has been accepted.") % cluster.id
-    utils.do_action_with_msg(cs.clusters.delete(cluster), msg)
+    """Delete specified cluster(s)."""
+    utils.do_action_on_many(
+        lambda s: cs.clusters.delete(_find_cluster(cs, s)),
+        args.cluster,
+        _("Request to delete cluster %s has been accepted."),
+        _("Unable to delete the specified cluster(s)."))
 
 
 @utils.arg('cluster', metavar='<cluster>',