1 files changed, 97 insertions, 0 deletions
diff --git a/src/ansiblelint/rules/command_instead_of_shell.py b/src/ansiblelint/rules/command_instead_of_shell.py
new file mode 100644
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+++ b/src/ansiblelint/rules/command_instead_of_shell.py
@@ -0,0 +1,97 @@
+"""Implementation of command-instead-of-shell rule."""
+# Copyright (c) 2016 Will Thames <will@thames.id.au>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+from __future__ import annotations
+
+import sys
+from typing import TYPE_CHECKING
+
+from ansiblelint.rules import AnsibleLintRule
+from ansiblelint.utils import get_cmd_args
+
+if TYPE_CHECKING:
+    from ansiblelint.file_utils import Lintable
+    from ansiblelint.utils import Task
+
+
+class UseCommandInsteadOfShellRule(AnsibleLintRule):
+    """Use shell only when shell functionality is required."""
+
+    id = "command-instead-of-shell"
+    description = (
+        "Shell should only be used when piping, redirecting "
+        "or chaining commands (and Ansible would be preferred "
+        "for some of those!)"
+    )
+    severity = "HIGH"
+    tags = ["command-shell", "idiom"]
+    version_added = "historic"
+
+    def matchtask(
+        self,
+        task: Task,
+        file: Lintable | None = None,
+    ) -> bool | str:
+        # Use unjinja so that we don't match on jinja filters
+        # rather than pipes
+        if task["action"]["__ansible_module__"] in ["shell", "ansible.builtin.shell"]:
+            # Since Ansible 2.4, the `command` module does not accept setting
+            # the `executable`. If the user needs to set it, they have to use
+            # the `shell` module.
+            if "executable" in task["action"]:
+                return False
+
+            jinja_stripped_cmd = self.unjinja(get_cmd_args(task))
+            return not any(ch in jinja_stripped_cmd for ch in "&|<>;$\n*[]{}?`")
+        return False
+
+
+# testing code to be loaded only with pytest or when executed the rule file
+if "pytest" in sys.modules:
+    import pytest
+
+    from ansiblelint.rules import RulesCollection  # pylint: disable=ungrouped-imports
+    from ansiblelint.runner import Runner  # pylint: disable=ungrouped-imports
+
+    @pytest.mark.parametrize(
+        ("file", "expected"),
+        (
+            pytest.param(
+                "examples/playbooks/rule-command-instead-of-shell-pass.yml",
+                0,
+                id="good",
+            ),
+            pytest.param(
+                "examples/playbooks/rule-command-instead-of-shell-fail.yml",
+                3,
+                id="bad",
+            ),
+        ),
+    )
+    def test_rule_command_instead_of_shell(
+        default_rules_collection: RulesCollection,
+        file: str,
+        expected: int,
+    ) -> None:
+        """Validate that rule works as intended."""
+        results = Runner(file, rules=default_rules_collection).run()
+        for result in results:
+            assert result.rule.id == UseCommandInsteadOfShellRule.id, result
+        assert len(results) == expected