Added throw error when event function name is long (zappa#1205)

* implement scheduled_event_name validation

* add too long function name test case

* update function name pattern in README

* fix black

* add event function pattern in docstring

* fixed pattern

* add error description

* add using invalid character test case

* add description

* fixed error mesasge

* fixed event function name pattern in README

---------

Co-authored-by: monkut <[email protected]>

README.md

@@ -932,11 +932,11 @@ to change Zappa's behavior. Use these at your own risk!
         "environment_variables": {"your_key": "your_value"}, // A dictionary of environment variables that will be available to your deployed app. See also "remote_env" and "aws_environment_variables". Default {}.
         "events": [
             {   // Recurring events
-                "function": "your_module.your_recurring_function", // The function to execute
+                "function": "your_module.your_recurring_function", // The function to execute (Pattern: [._A-Za-z0-9]+).
                 "expression": "rate(1 minute)" // When to execute it (in cron or rate format)
             },
             {   // AWS Reactive events
-                "function": "your_module.your_reactive_function", // The function to execute
+                "function": "your_module.your_reactive_function", // The function to execute (Pattern: [._A-Za-z0-9]+).
                 "event_source": {
                     "arn":  "arn:aws:s3:::my-bucket", // The ARN of this event source
                     "events": [

tests/tests.py

@@ -2238,6 +2238,52 @@ def test_get_scheduled_event_name__truncated__has_name__has_index(self):
             f"{hashed_lambda_name}-{index}-{event['name']}-{function}",
         )
 
+    def test_get_scheduled_event_name__using_invalid_character(self):
+        zappa = Zappa()
+        event = {}
+        function = "foo$"
+        lambda_name = "bar"
+        with self.assertRaises(EnvironmentError):
+            zappa.get_scheduled_event_name(event, function, lambda_name)
+
+    def test_get_scheduled_event_name__using_hyphen(self):
+        zappa = Zappa()
+        event = {}
+        function = "foo-2"
+        lambda_name = "bar"
+        with self.assertRaises(EnvironmentError):
+            zappa.get_scheduled_event_name(event, function, lambda_name)
+
+    def test_get_scheduled_event_name__max_function_name(self):
+        zappa = Zappa()
+        event = {}
+        function = "a" * 63
+        lambda_name = "bar"
+
+        self.assertEqual(
+            zappa.get_scheduled_event_name(event, function, lambda_name),
+            f"-{function}",
+        )
+
+    def test_get_scheduled_event_name__over_function_name(self):
+        zappa = Zappa()
+        event = {}
+        function = "a" * 64
+        lambda_name = "bar"
+
+        with self.assertRaises(EnvironmentError):
+            zappa.get_scheduled_event_name(event, function, lambda_name)
+
+    def test_get_scheduled_event_name__over_name_with_index(self):
+        zappa = Zappa()
+        event = {}
+        function = "a" * 62
+        index = 1
+        lambda_name = "bar"
+
+        with self.assertRaises(EnvironmentError):
+            zappa.get_scheduled_event_name(event, function, lambda_name, index)
+
     def test_shameless(self):
         shamelessly_promote()
 

zappa/core.py

@@ -2939,7 +2939,17 @@ def get_scheduled_event_name(self, event, function, lambda_name, index=0):
         """
         Returns an AWS-valid CloudWatch rule name using a digest of the event name, lambda name, and function.
         This allows support for rule names that may be longer than the 64 char limit.
+
+        function pattern: '^[._A-Za-z0-9]{0,63}$'
         """
+        max_event_rule_name_length = 64
+        max_name_length = max_event_rule_name_length - 1  # Because it must contain the delimiter "-".
+        function_regex = re.compile(f"^[._A-Za-z0-9]{{0,{max_name_length}}}$")
+        if not re.fullmatch(function_regex, function):
+            # Validation Rule: https://docs.aws.amazon.com/eventbridge/latest/APIReference/API_Rule.html
+            # '-' cannot be used because it is a delimiter
+            raise EnvironmentError("event['function']: Pattern '^[._A-Za-z0-9]{0,63}$'.")
+
         name = event.get("name", function)
         if name != function:
             # a custom event name has been provided, make sure function name is included as postfix,
@@ -2950,11 +2960,16 @@ def get_scheduled_event_name(self, event, function, lambda_name, index=0):
             # prefix all entries bar the first with the index
             # Related: https://github.com/Miserlou/Zappa/pull/1051
             name = "{}-{}".format(index, name)
+
+        # https://github.com/zappa/Zappa/issues/1036
+        # Error because the name cannot be obtained if the function name is longer than 64 characters
+        if len(name) > max_name_length:
+            raise EnvironmentError(f"Generated scheduled event name is too long, shorten the function name!: '{name}'")
         # prefix scheduled event names with lambda name. So we can look them up later via the prefix.
         event_name = self.get_event_name(lambda_name, name)
         # if it's possible that we truncated name, generate a unique, shortened name
         # https://github.com/Miserlou/Zappa/issues/970
-        if len(event_name) >= 64:
+        if len(event_name) >= max_event_rule_name_length:
             lambda_name = self.get_hashed_lambda_name(lambda_name)
             event_name = self.get_event_name(lambda_name, name)