core - add ability to add custom functions to jmespath

c7n/__init__.py

@@ -1,3 +1,14 @@
 # Copyright The Cloud Custodian Authors.
 # SPDX-License-Identifier: Apache-2.0
 #
+
+import jmespath
+from functools import partial
+from c7n.utils import C7NJmespathFunctions
+
+jmespath.search = partial(
+    jmespath.search,
+    options=jmespath.Options(
+        custom_functions=C7NJmespathFunctions()
+    )
+)

c7n/utils.py

@@ -13,10 +13,10 @@
 import sys
 import threading
 import time
+from jmespath import functions
 from urllib import parse as urlparse
 from urllib.request import getproxies, proxy_bypass
 
-
 from dateutil.parser import ParserError, parse
 
 from c7n import config
@@ -912,3 +912,11 @@
     else:
         rtype = 'unknown'
     return rtype
+
+
+class C7NJmespathFunctions(functions.Functions):
+    @functions.signature(
+        {'types': ['string']}, {'types': ['string']}
+    )
+    def _func_split(self, sep, string):
+        return string.split(sep)