Fixing get_rule_file_hash to always return bytes

elastalert/loaders.py

@@ -606,12 +606,14 @@ def get_import_rule(self, rule):
         return expanded_imports
 
     def get_rule_file_hash(self, rule_file):
-        rule_file_hash = ''
         if os.path.exists(rule_file):
             with open(rule_file, 'rb') as fh:
                 rule_file_hash = hashlib.sha1(fh.read()).digest()
             for import_rule_file in self.import_rules.get(rule_file, []):
                 rule_file_hash += self.get_rule_file_hash(import_rule_file)
+        else:
+            not_found = 'ENOENT ' + rule_file
+            rule_file_hash = hashlib.sha1(not_found.encode('utf-8')).digest()
         return rule_file_hash
 
     @staticmethod

tests/loaders_test.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from base64 import b64encode
 import copy
 import datetime
 import os
@@ -488,3 +489,12 @@ def test_get_import_rule():
     }
     result = RulesLoader.get_import_rule('', rule)
     assert 'a' == result
+
+
+def test_get_rule_file_hash_when_file_not_found():
+    test_config_copy = copy.deepcopy(test_config)
+    rules_loader = FileRulesLoader(test_config_copy)
+    hash = rules_loader.get_rule_file_hash('empty_folder_test/file_not_found.yml')
+    assert isinstance(hash, bytes)
+    b64Hash = b64encode(hash).decode('ascii')
+    assert 'zR1Ml8y8S8Z/I5j7b48OH+DJqUw=' == b64Hash