| """ |
| Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. |
| SPDX-License-Identifier: MIT-0 |
| """ |
|
|
| from __future__ import unicode_literals |
|
|
| from cfnlint._typing import RuleMatches |
| from cfnlint.rules import CloudFormationLintRule, RuleMatch |
| from cfnlint.template import Template |
|
|
|
|
| class Used(CloudFormationLintRule): |
| """Check if Parameters are used""" |
|
|
| id = "W2001" |
| shortdesc = "Check if Parameters are Used" |
| description = "Making sure the parameters defined are used" |
| source_url = "https://github.com/aws-cloudformation/cfn-lint" |
| tags = ["parameters"] |
|
|
| def match(self, cfn: Template) -> RuleMatches: |
| if cfn.transform_pre["Transform"]: |
| return [] |
| matches: RuleMatches = [] |
|
|
| le_refs = None |
| if cfn.has_language_extensions_transform(): |
| le_refs = cfn.search_deep_keys("Ref") |
|
|
| reftrees = cfn.transform_pre.get("Ref", []) |
| subtrees = cfn.transform_pre.get("Fn::Sub", []) |
| refs = [] |
| for reftree in reftrees: |
| refs.append(reftree[-1]) |
| if le_refs: |
| for le_ref in le_refs: |
| if le_ref[-1] not in refs: |
| refs.append(le_ref[-1]) |
|
|
| subs = [] |
| for subtree in subtrees: |
| if isinstance(subtree[-1], list): |
| subs.extend(cfn.get_sub_parameters(subtree[-1][0])) |
| elif isinstance(subtree[-1], str): |
| subs.extend(cfn.get_sub_parameters(subtree[-1])) |
|
|
| for paramname in cfn.template.get("Parameters", {}).keys(): |
| if paramname not in refs: |
| if paramname not in subs: |
| message = "Parameter {0} not used." |
| matches.append( |
| RuleMatch(["Parameters", paramname], message.format(paramname)) |
| ) |
|
|
| return matches |
|
|
