Add support for acceptable command options

.flake8

@@ -70,6 +70,7 @@ per-file-ignores =
   test/TestBaseFormatter.py: D100 D103
   test/TestBecomeUserWithoutBecome.py: PT009 D100 D101 D102
   test/TestCliRolePaths.py: PT009 D100 D101 D102
+  test/TestCommandsInsteadOfModulesRule.py: PT009
   test/TestCommandLineInvocationSameAsConfig.py: D100 D103
   test/TestCommandHasChangesCheck.py: PT009 D100 D101 D102
   test/TestComparisonToEmptyString.py: PT009 D100 D101 D102

examples/playbooks/commands-instead-of-modules-failure.yml

@@ -0,0 +1,11 @@
+---
+- hosts: localhost
+  tasks:
+    - name: print git log
+      command: git log
+
+    - name: run apt-get update
+      command: apt-get update
+
+    - name: restart sshd
+      command: systemctl restart sshd

examples/playbooks/commands-instead-of-modules-success.yml

@@ -0,0 +1,11 @@
+---
+- hosts: localhost
+  tasks:
+    - name: set systemd runlevel
+      command: systemctl set-default multi-user.target
+
+    - name: show systemd environment
+      command: systemctl show-environment
+
+    - name: print current git branch
+      command: git branch

src/ansiblelint/rules/CommandsInsteadOfModulesRule.py

@@ -22,7 +22,7 @@
 from typing import Any, Dict, Union
 
 from ansiblelint.rules import AnsibleLintRule
-from ansiblelint.utils import convert_to_boolean, get_first_cmd_arg
+from ansiblelint.utils import convert_to_boolean, get_first_cmd_arg, get_second_cmd_arg
 
 
 class CommandsInsteadOfModulesRule(AnsibleLintRule):
@@ -59,15 +59,30 @@ class CommandsInsteadOfModulesRule(AnsibleLintRule):
         'yum': 'yum',
     }
 
+    _executable_options = {
+        'git': 'branch',
+        'systemctl': ['set-default', 'show-environment'],
+    }
+
     def matchtask(self, task: Dict[str, Any]) -> Union[bool, str]:
         if task['action']['__ansible_module__'] not in self._commands:
             return False
 
         first_cmd_arg = get_first_cmd_arg(task)
+        second_cmd_arg = get_second_cmd_arg(task)
+
         if not first_cmd_arg:
             return False
 
         executable = os.path.basename(first_cmd_arg)
+
+        if (
+            second_cmd_arg
+            and executable in self._executable_options
+            and second_cmd_arg in self._executable_options[executable]
+        ):
+            return False
+
         if executable in self._modules and convert_to_boolean(
             task['action'].get('warn', True)
         ):

src/ansiblelint/utils.py

@@ -752,6 +752,17 @@ def get_first_cmd_arg(task: Dict[str, Any]) -> Any:
     return first_cmd_arg
 
 
+def get_second_cmd_arg(task: Dict[str, Any]) -> Any:
+    try:
+        if 'cmd' in task['action']:
+            second_cmd_arg = task['action']['cmd'].split()[1]
+        else:
+            second_cmd_arg = task['action']['__ansible_arguments__'][1]
+    except IndexError:
+        return None
+    return second_cmd_arg
+
+
 def is_playbook(filename: str) -> bool:
     """
     Check if the file is a playbook.

test/TestCommandsInsteadOfModulesRule.py

@@ -0,0 +1,30 @@
+# pylint: disable=preferred-module  # FIXME: remove once migrated per GH-725
+"""command-instead-of-module rule testing."""
+import unittest
+
+from ansiblelint.rules import RulesCollection
+from ansiblelint.rules.CommandsInsteadOfModulesRule import CommandsInsteadOfModulesRule
+from ansiblelint.runner import Runner
+
+
+class TestCommandsInsteadOfModulesRule(unittest.TestCase):
+    """Unit test for command-instead-of-module rule."""
+
+    collection = RulesCollection()
+
+    def setUp(self):
+        """Register rule."""
+        self.collection.register(CommandsInsteadOfModulesRule())
+
+    def test_file_positive(self):
+        """Run tasks that should be successful."""
+        success = 'examples/playbooks/commands-instead-of-modules-success.yml'
+        good_runner = Runner(success, rules=self.collection)
+        self.assertEqual([], good_runner.run())
+
+    def test_file_negative(self):
+        """Run tasks that should fail."""
+        failure = 'examples/playbooks/commands-instead-of-modules-failure.yml'
+        bad_runner = Runner(failure, rules=self.collection)
+        errs = bad_runner.run()
+        self.assertEqual(3, len(errs))