vm: fail renew if it shortens expiration

unless forced

circle/dashboard/forms.py

@@ -697,16 +697,18 @@ class LeaseForm(forms.ModelForm):
 
 class VmRenewForm(forms.Form):
 
+    force = forms.BooleanField(required=False, label=_(
+        "Set expiration times even if they are shorter than "
+        "the current value."))
+
     def __init__(self, *args, **kwargs):
         choices = kwargs.pop('choices')
         default = kwargs.pop('default')
         super(VmRenewForm, self).__init__(*args, **kwargs)
 
-        self.fields['lease'] = forms.ModelChoiceField(queryset=choices,
-                                                      initial=default,
-                                                      required=False,
-                                                      empty_label=None,
-                                                      label=_('Length'))
+        self.fields.insert(0, 'lease', forms.ModelChoiceField(
+            queryset=choices, initial=default, required=False,
+            empty_label=None, label=_('Length')))
         if len(choices) < 2:
             self.fields['lease'].widget = HiddenInput()
 

circle/vm/operations.py

@@ -28,7 +28,9 @@ from sizefield.utils import filesizeformat
 
 from celery.exceptions import TimeLimitExceeded
 
-from common.models import create_readable, humanize_exception
+from common.models import (
+    create_readable, humanize_exception, HumanReadableException
+)
 from common.operations import Operation, register_operation
 from .tasks.local_tasks import (
     abortable_async_instance_operation, abortable_async_node_operation,
@@ -716,10 +718,24 @@ class RenewOperation(InstanceOperation):
     required_perms = ()
     concurrency_check = False
 
-    def _operation(self, lease=None):
-        (self.instance.time_of_suspend,
-         self.instance.time_of_delete) = self.instance.get_renew_times(lease)
+    def _operation(self, activity, lease=None, force=False):
+        suspend, delete = self.instance.get_renew_times(lease)
+        if (not force and suspend and self.instance.time_of_suspend and
+                suspend < self.instance.time_of_suspend):
+            raise HumanReadableException.create(ugettext_noop(
+                "Renewing the machine with the selected lease would result "
+                "in its suspension time get earlier than before."))
+        if (not force and delete and self.instance.time_of_delete and
+                delete < self.instance.time_of_delete):
+            raise HumanReadableException.create(ugettext_noop(
+                "Renewing the machine with the selected lease would result "
+                "in its delete time get earlier than before."))
+        self.instance.time_of_suspend = suspend
+        self.instance.time_of_delete = delete
         self.instance.save()
+        activity.result = create_readable(ugettext_noop(
+            "Renewed to suspend at %(suspend)s and destroy at %(delete)s."),
+            suspend=suspend, delete=delete)
 
 
 register_operation(RenewOperation)