1 files changed, 34 insertions, 1 deletions
diff --git a/roles/openshift_aws/filter_plugins/openshift_aws_filters.py b/roles/openshift_aws/filter_plugins/openshift_aws_filters.py
index e707abd3f..dfcb11da3 100644
--- a/roles/openshift_aws/filter_plugins/openshift_aws_filters.py
+++ b/roles/openshift_aws/filter_plugins/openshift_aws_filters.py
@@ -4,11 +4,43 @@
 Custom filters for use in openshift_aws
 '''
 
+from ansible import errors
+
 
 class FilterModule(object):
     ''' Custom ansible filters for use by openshift_aws role'''
 
     @staticmethod
+    def scale_groups_serial(scale_group_info, upgrade=False):
+        ''' This function will determine what the deployment serial should be and return it
+
+          Search through the tags and find the deployment_serial tag. Once found,
+          determine if an increment is needed during an upgrade.
+          if upgrade is true then increment the serial and return it
+          else return the serial
+        '''
+        if scale_group_info == []:
+            return 1
+
+        scale_group_info = scale_group_info[0]
+
+        if not isinstance(scale_group_info, dict):
+            raise errors.AnsibleFilterError("|filter plugin failed: Expected scale_group_info to be a dict")
+
+        serial = None
+
+        for tag in scale_group_info['tags']:
+            if tag['key'] == 'deployment_serial':
+                serial = int(tag['value'])
+                if upgrade:
+                    serial += 1
+                break
+        else:
+            raise errors.AnsibleFilterError("|filter plugin failed: deployment_serial tag was not found")
+
+        return serial
+
+    @staticmethod
     def scale_groups_match_capacity(scale_group_info):
         ''' This function will verify that the scale group instance count matches
             the scale group desired capacity
@@ -38,4 +70,5 @@ class FilterModule(object):
     def filters(self):
         ''' returns a mapping of filters to methods '''
         return {'build_instance_tags': self.build_instance_tags,
-                'scale_groups_match_capacity': self.scale_groups_match_capacity}
+                'scale_groups_match_capacity': self.scale_groups_match_capacity,
+                'scale_groups_serial': self.scale_groups_serial}