def match()

in shared/lint/rules/custom_rules.py [0:0]

• 21 lines of code
• 9 McCabe index (conditional complexity)

    def match(self, cfn):
        """
        Match functions that don't have a log group
        """

        matches = []

        functions = cfn.get_resources("AWS::Lambda::Function")
        log_groups = cfn.get_resources("AWS::Logs::LogGroup")

        known = []

        # Scan log groups for resource names
        for resource in log_groups.values():
            # This use an autogenerated log group name
            if "LogGroupName" not in resource.get("Properties"):
                continue

            log_group_name = resource.get("Properties").get("LogGroupName")
            # This doesn't have a !Sub transformation
            if not isinstance(log_group_name, dict) or "Fn::Sub" not in log_group_name:
                continue

            match = re.search(r"\${(?P<func>[^}]+)}", log_group_name["Fn::Sub"])
            if match is not None:
                known.append(match["func"])

        # Scan functions against log groups
        for function in functions.keys():
            if function not in known:
                matches.append(RuleMatch(
                    ["Resources", function],
                    self._message.format(function)
                ))

        return matches