Separate geting flavors and filtering into separe tasks

Also minimalize numbers of calls to nova API

Signed-off-by: Dawid Deja <dawid.deja@intel.com>

find_flavors_by_extra_spec.py

@@ -0,0 +1,32 @@
+"""
+FindFlavorsByExtraSpecs - custom action.
+
+It works pretty similar to nova.flavors_findall, but it looks for items in
+flavors extra spec
+"""
+
+from mistral.actions.openstack.actions import NovaAction
+
+
+class FindFlavorsByExtraSpecs(NovaAction):
+
+    def __init__(self, extra_specs):
+        if type(extra_specs) is dict:
+            self._extra_specs = extra_specs
+        else:
+            raise TypeError("Extra spec must be a dictionary")
+
+    def run(self):
+        client = self._get_client()
+        flavors = client.flavors.list()
+        result = []
+
+        for flavor in flavors:
+            flavor_extra_specs = flavor.get_keys().items()
+            if all(
+                    item in flavor_extra_specs
+                    for item in self._extra_specs.items()
+            ):
+                result.append(flavor.id)
+
+        return result