Allow configurations for each rule stored in ansiblelint.config.options

Add ansiblelint.config.options.rules: Dict[str, Any] to store
configurations for each rule and utilize them from each rule to allow
customize behaviors of rules more flexibly.

Signed-Off-By: Satoru SATOH <satoru.satoh@gmail.com>

src/ansiblelint/config.py

@@ -5,7 +5,7 @@
 import sys
 from argparse import Namespace
 from functools import lru_cache
-from typing import Dict, List, Optional, Tuple
+from typing import Any, Dict, List, Optional, Tuple
 
 from packaging.version import Version
 
@@ -84,6 +84,7 @@
     extra_vars=None,
     enable_list=[],
     skip_action_validation=True,
+    rules=dict(),  # Placeholder to set and keep configurations for each rule.
 )
 
 # Used to store detected tag deprecations
@@ -93,6 +94,11 @@
 collection_list: List[str] = []
 
 
+def get_rule_config(rule_id: str) -> Dict[str, Any]:
+    """Get configurations for the rule ``rule_id``."""
+    return options.rules.get(rule_id, dict())
+
+
 @lru_cache()
 def ansible_collections_path() -> str:
     """Return collection path variable for current version of Ansible."""

src/ansiblelint/rules/__init__.py

@@ -7,8 +7,9 @@
 import re
 from argparse import Namespace
 from collections import defaultdict
+from functools import lru_cache
 from importlib.abc import Loader
-from typing import Iterator, List, Optional, Set, Union
+from typing import Any, Dict, Iterator, List, Optional, Set, Union
 
 import ansiblelint.utils
 from ansiblelint._internal.rules import (
@@ -17,7 +18,7 @@
     LoadingFailureRule,
     RuntimeErrorRule,
 )
-from ansiblelint.config import options
+from ansiblelint.config import get_rule_config, options
 from ansiblelint.errors import MatchError
 from ansiblelint.file_utils import Lintable
 from ansiblelint.skip_utils import append_skipped_rules, get_rule_skips_from_line
@@ -26,6 +27,15 @@
 
 
 class AnsibleLintRule(BaseRule):
+    @property
+    def rule_config(self) -> Dict[str, Any]:
+        return get_rule_config(self.id)
+
+    @lru_cache()
+    def get_config(self, key: str) -> Any:
+        """Return a configured value for given key string."""
+        return self.rule_config.get(key, None)
+
     def __repr__(self) -> str:
         """Return a AnsibleLintRule instance representation."""
         return self.id + ": " + self.shortdesc

test/TestAnsibleLintRule.py

@@ -1,7 +1,21 @@
+import pytest
+
+from ansiblelint.config import options
 from ansiblelint.rules import AnsibleLintRule
 
 
 def test_unjinja():
     text = "{{ a }} {% b %} {# try to confuse parsing inside a comment { {{}} } #}"
     output = "JINJA_EXPRESSION JINJA_STATEMENT JINJA_COMMENT"
     assert AnsibleLintRule.unjinja(text) == output
+
+
+@pytest.mark.parametrize('rule_config', (dict(), dict(foo=True, bar=1)))
+def test_rule_config(rule_config, monkeypatch):
+    rule_id = 'rule-0'
+    monkeypatch.setattr(AnsibleLintRule, 'id', rule_id)
+    monkeypatch.setitem(options.rules, rule_id, rule_config)
+
+    rule = AnsibleLintRule()
+    assert set(rule.rule_config.items()) == set(rule_config.items())
+    assert all(rule.get_config(k) == v for k, v in rule_config.items())