Merge pull request #2764 from bblommers/feature/ec2-describe-instance-filters

Feature  - EC2 describe_instance_status now uses filters

moto/ec2/models.py

@@ -822,6 +822,21 @@ class Instance(TaggedEC2Resource, BotoInstance):
             return self.public_ip
         raise UnformattedGetAttTemplateException()
 
+    def applies(self, filters):
+        if filters:
+            applicable = False
+            for f in filters:
+                acceptable_values = f["values"]
+                if f["name"] == "instance-state-name":
+                    if self._state.name in acceptable_values:
+                        applicable = True
+                if f["name"] == "instance-state-code":
+                    if str(self._state.code) in acceptable_values:
+                        applicable = True
+            return applicable
+        # If there are no filters, all instances are valid
+        return True
+
 
 class InstanceBackend(object):
     def __init__(self):
@@ -921,22 +936,23 @@ class InstanceBackend(object):
         value = getattr(instance, key)
         return instance, value
 
-    def all_instances(self):
+    def all_instances(self, filters=None):
         instances = []
         for reservation in self.all_reservations():
             for instance in reservation.instances:
-                instances.append(instance)
-        return instances
-
-    def all_running_instances(self):
-        instances = []
-        for reservation in self.all_reservations():
-            for instance in reservation.instances:
-                if instance.state_code == 16:
+                if instance.applies(filters):
                     instances.append(instance)
         return instances
 
-    def get_multi_instances_by_id(self, instance_ids):
+    def all_running_instances(self, filters=None):
+        instances = []
+        for reservation in self.all_reservations():
+            for instance in reservation.instances:
+                if instance.state_code == 16 and instance.applies(filters):
+                    instances.append(instance)
+        return instances
+
+    def get_multi_instances_by_id(self, instance_ids, filters=None):
         """
         :param instance_ids: A string list with instance ids
         :return: A list with instance objects
@@ -946,7 +962,8 @@ class InstanceBackend(object):
         for reservation in self.all_reservations():
             for instance in reservation.instances:
                 if instance.id in instance_ids:
-                    result.append(instance)
+                    if instance.applies(filters):
+                        result.append(instance)
 
         # TODO: Trim error message down to specific invalid id.
         if instance_ids and len(instance_ids) > len(result):

moto/ec2/responses/instances.py

@@ -113,16 +113,34 @@ class InstanceResponse(BaseResponse):
             template = self.response_template(EC2_START_INSTANCES)
             return template.render(instances=instances)
 
+    def _get_list_of_dict_params(self, param_prefix, _dct):
+        """
+        Simplified version of _get_dict_param
+        Allows you to pass in a custom dict instead of using self.querystring by default
+        """
+        params = []
+        for key, value in _dct.items():
+            if key.startswith(param_prefix):
+                params.append(value)
+        return params
+
     def describe_instance_status(self):
         instance_ids = self._get_multi_param("InstanceId")
         include_all_instances = self._get_param("IncludeAllInstances") == "true"
+        filters = self._get_list_prefix("Filter")
+        filters = [
+            {"name": f["name"], "values": self._get_list_of_dict_params("value.", f)}
+            for f in filters
+        ]
 
         if instance_ids:
-            instances = self.ec2_backend.get_multi_instances_by_id(instance_ids)
+            instances = self.ec2_backend.get_multi_instances_by_id(
+                instance_ids, filters
+            )
         elif include_all_instances:
-            instances = self.ec2_backend.all_instances()
+            instances = self.ec2_backend.all_instances(filters)
         else:
-            instances = self.ec2_backend.all_running_instances()
+            instances = self.ec2_backend.all_running_instances(filters)
 
         template = self.response_template(EC2_INSTANCE_STATUS)
         return template.render(instances=instances)