Accommodate specified inventory files

The ansible_cfg_inventory conditional in the _get_inventory_files method
is used because otherwise, when not passing in an inventory file via
CLI, inventory_files would set to the /etc/ansible/hosts (the default
value for the DEFAULT_HOST_LIST config). In most cases, I'd presume that
wouldn't be desired.

examples/playbooks/test_using_inventory.yml

@@ -0,0 +1,11 @@
+---
+- name: Test
+  hosts:
+    - group_name
+  serial: "{{ batch | default(groups['group_name'] | length) }}"
+  gather_facts: false
+  tasks:
+    - name: Debug
+      delegate_to: localhost
+      ansible.builtin.debug:
+        msg: "{{ batch | default(groups['group_name'] | length) }}"

inventories/bad_inventory

@@ -0,0 +1,7 @@
+[group]
+= = I
+= = am
+= = not
+= = a
+= = valid
+= = inventory

inventories/bar

@@ -0,0 +1,4 @@
+not_the_group_name:
+    hosts:
+        host1:
+        host2:

inventories/baz

@@ -0,0 +1,4 @@
+group_name:
+    hosts:
+        host1:
+        host2:

inventories/foo

@@ -0,0 +1,4 @@
+group_name:
+    hosts:
+        host1:
+        host2:

src/ansiblelint/cli.py

@@ -456,6 +456,14 @@ def get_cli_parser() -> argparse.ArgumentParser:
         default=None,
         help=f"Specify ignore file to use. By default it will look for '{IGNORE_FILE.default}' or '{IGNORE_FILE.alternative}'",
     )
+    parser.add_argument(
+        "-I",
+        "--inventory",
+        dest="inventory",
+        action="append",
+        type=str,
+        help="Specify inventory host path or comma separated host list",
+    )
     parser.add_argument(
         "--offline",
         dest="offline",

src/ansiblelint/config.py

@@ -173,6 +173,7 @@ class Options:  # pylint: disable=too-many-instance-attributes
     version: bool = False  # display version command
     list_profiles: bool = False  # display profiles command
     ignore_file: Path | None = None
+    inventory: list[str] | None = None
     max_tasks: int = 100
     max_block_depth: int = 20
     # Refer to https://docs.ansible.com/ansible/latest/reference_appendices/release_and_maintenance.html#ansible-core-support-matrix

src/ansiblelint/runner.py

@@ -18,8 +18,12 @@
 from pathlib import Path
 from tempfile import NamedTemporaryFile
 from typing import TYPE_CHECKING, Any
+from unittest import mock
 
+import ansible.inventory.manager
+from ansible.config.manager import ConfigManager
 from ansible.errors import AnsibleError
+from ansible.parsing.dataloader import DataLoader
 from ansible.parsing.splitter import split_args
 from ansible.parsing.yaml.constructor import AnsibleMapping
 from ansible.plugins.loader import add_all_plugin_dirs
@@ -340,13 +344,16 @@ def _get_ansible_syntax_check_matches(
                 playbook_path = fh.name
             else:
                 playbook_path = str(lintable.path.expanduser())
-            # To avoid noisy warnings we pass localhost as current inventory:
-            # [WARNING]: No inventory was parsed, only implicit localhost is available
-            # [WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'
             cmd = [
                 "ansible-playbook",
-                "-i",
-                "localhost,",
+                *[
+                    inventory_opt
+                    for inventory_opts in [
+                        ("-i", inventory_file)
+                        for inventory_file in self._get_inventory_files(app)
+                    ]
+                    for inventory_opt in inventory_opts
+                ],
                 "--syntax-check",
                 playbook_path,
             ]
@@ -451,6 +458,62 @@ def _get_ansible_syntax_check_matches(
             fh.close()
         return results
 
+    def _get_inventory_files(self, app: App) -> list[str]:
+        config_mgr = ConfigManager()
+        ansible_cfg_inventory = config_mgr.get_config_value(
+            "DEFAULT_HOST_LIST",
+        )
+        if app.options.inventory or ansible_cfg_inventory != [
+            config_mgr.get_configuration_definitions()["DEFAULT_HOST_LIST"].get(
+                "default",
+            ),
+        ]:
+            inventory_files = [
+                inventory_file
+                for inventory_list in [
+                    # creates nested inventory list
+                    (inventory.split(",") if "," in inventory else [inventory])
+                    for inventory in (
+                        app.options.inventory
+                        if app.options.inventory
+                        else ansible_cfg_inventory
+                    )
+                ]
+                for inventory_file in inventory_list
+            ]
+
+            # silence noise when using parse_source
+            with mock.patch.object(
+                ansible.inventory.manager,
+                "display",
+                mock.Mock(),
+            ):
+                for inventory_file in inventory_files:
+                    if not Path(inventory_file).exists():
+                        _logger.warning(
+                            "Unable to use %s as an inventory source: no such file or directory",
+                            inventory_file,
+                        )
+                    elif os.access(
+                        inventory_file,
+                        os.R_OK,
+                    ) and not ansible.inventory.manager.InventoryManager(
+                        DataLoader(),
+                    ).parse_source(
+                        inventory_file,
+                    ):
+                        _logger.warning(
+                            "Unable to parse %s as an inventory source",
+                            inventory_file,
+                        )
+        else:
+            # To avoid noisy warnings we pass localhost as current inventory:
+            # [WARNING]: No inventory was parsed, only implicit localhost is available
+            # [WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'
+            inventory_files = ["localhost"]
+
+        return inventory_files
+
     def _filter_excluded_matches(self, matches: list[MatchError]) -> list[MatchError]:
         return [
             match

test/test_app.py

@@ -2,6 +2,8 @@
 
 from pathlib import Path
 
+import pytest
+
 from ansiblelint.constants import RC
 from ansiblelint.file_utils import Lintable
 from ansiblelint.testing import run_ansible_lint
@@ -29,3 +31,69 @@ def test_app_no_matches(tmp_path: Path) -> None:
     """Validate that linter returns special exit code if no files are analyzed."""
     result = run_ansible_lint(cwd=tmp_path)
     assert result.returncode == RC.NO_FILES_MATCHED
+
+
+@pytest.mark.parametrize(
+    "inventory_opts",
+    (
+        pytest.param(["-I", "inventories/foo"], id="1"),
+        pytest.param(
+            [
+                "-I",
+                "inventories/bar",
+                "-I",
+                "inventories/baz",
+            ],
+            id="2",
+        ),
+        pytest.param(
+            [
+                "-I",
+                "inventories/foo,inventories/bar",
+                "-I",
+                "inventories/baz",
+            ],
+            id="3",
+        ),
+    ),
+)
+def test_with_inventory(inventory_opts: list[str]) -> None:
+    """Validate using --inventory remedies syntax-check[specific] violation."""
+    lintable = Lintable("examples/playbooks/test_using_inventory.yml")
+    result = run_ansible_lint(lintable.filename, *inventory_opts)
+    assert result.returncode == RC.SUCCESS
+
+
+@pytest.mark.parametrize(
+    ("inventory_opts", "error_msg"),
+    (
+        pytest.param(
+            ["-I", "inventories/i_dont_exist"],
+            "Unable to use inventories/i_dont_exist as an inventory source: no such file or directory",
+            id="1",
+        ),
+        pytest.param(
+            ["-I", "inventories/bad_inventory"],
+            "Unable to parse inventories/bad_inventory as an inventory source",
+            id="2",
+        ),
+    ),
+)
+def test_with_inventory_emit_warning(inventory_opts: list[str], error_msg: str) -> None:
+    """Validate using --inventory can emit useful warnings about inventory files."""
+    lintable = Lintable("examples/playbooks/test_using_inventory.yml")
+    result = run_ansible_lint(lintable.filename, *inventory_opts)
+    assert error_msg in result.stderr
+
+
+def test_with_inventory_via_ansible_cfg(tmp_path: Path) -> None:
+    """Validate using inventory file from ansible.cfg remedies syntax-check[specific] violation."""
+    (tmp_path / "ansible.cfg").write_text("[defaults]\ninventory = foo\n")
+    (tmp_path / "foo").write_text("[group_name]\nhost1\nhost2\n")
+    lintable = Lintable(tmp_path / "playbook.yml")
+    lintable.content = "---\n- name: Test\n  hosts:\n    - group_name\n  serial: \"{{ batch | default(groups['group_name'] | length) }}\"\n"
+    lintable.kind = "playbook"
+    lintable.write(force=True)
+
+    result = run_ansible_lint(lintable.filename, cwd=tmp_path)
+    assert result.returncode == RC.SUCCESS

tox.ini

@@ -75,7 +75,7 @@ setenv =
   PRE_COMMIT_COLOR = always
   # Number of expected test passes, safety measure for accidental skip of
   # tests. Update value if you add/remove tests. (tox-extra)
-  PYTEST_REQPASS = 895
+  PYTEST_REQPASS = 901
   FORCE_COLOR = 1
   pre: PIP_PRE = 1
 allowlist_externals =