Add ERROR_ON_EMPTY_INVENTORY configuration option (#85853)

changelogs/fragments/85853-error-on-empty-inventory.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - add new configuration option ``ERROR_ON_EMPTY_INVENTORY`` (env var ``ANSIBLE_ERROR_ON_EMPTY_INVENTORY``) to control whether empty inventories should raise an error or show a warning. (https://github.com/ansible/ansible/issues/85853)

lib/ansible/cli/__init__.py

@@ -587,8 +587,10 @@ class CLI(ABC):
     def get_host_list(inventory, subset, pattern='all'):
 
         no_hosts = False
+        # Empty inventory
         if len(inventory.list_hosts()) == 0:
-            # Empty inventory
+            if C.ERROR_ON_EMPTY_INVENTORY:
+                raise AnsibleError("No hosts found in inventory")
             if C.LOCALHOST_WARNING and pattern not in C.LOCALHOST:
                 display.warning("provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'")
             no_hosts = True

lib/ansible/config/base.yml

@@ -1404,6 +1404,15 @@ DUPLICATE_YAML_DICT_KEY:
     warn: issue a warning but continue
     ignore: just continue silently
   version_added: "2.9"
+ERROR_ON_EMPTY_INVENTORY:
+    name: Empty inventory error
+    default: False
+    description: "Toggle to allow empty inventory to become an error instead of a warning."
+    env: [{name: ANSIBLE_ERROR_ON_EMPTY_INVENTORY}]
+    ini:
+    - {key: error_on_empty_inventory, section: defaults}
+    type: boolean
+    version_added: "2.20"
 ERROR_ON_MISSING_HANDLER:
   name: Missing handler error
   default: True

test/units/cli/test_cli.py

@@ -29,6 +29,7 @@ from units.mock.loader import DictDataLoader
 from ansible.release import __version__
 from ansible.parsing import vault
 from ansible import cli
+from ansible.errors import AnsibleError
 
 
 class TestCliVersion(unittest.TestCase):
@@ -364,3 +365,28 @@ class TestCliSetupVaultSecrets(unittest.TestCase):
         self.assertIsInstance(res, list)
         match = vault.match_secrets(res, ['some_vault_id'])[0][1]
         self.assertEqual(match.bytes, b'prompt1_password')
+
+
+class TestGetHostListEmptyInventory:
+    def setup_method(self):
+        self.mock_inventory = MagicMock()
+
+    @patch('ansible.cli.C.ERROR_ON_EMPTY_INVENTORY', True)
+    def test_get_host_list_empty_inventory_error_on(self):
+        """Test that AnsibleError is raised when ERROR_ON_EMPTY_INVENTORY is True and inventory is empty"""
+
+        self.mock_inventory.list_hosts.return_value = []
+
+        with pytest.raises(AnsibleError, match="No hosts found in inventory"):
+            cli.CLI.get_host_list(self.mock_inventory, None, 'all')
+
+    @patch('ansible.cli.C.ERROR_ON_EMPTY_INVENTORY', False)
+    @patch('ansible.cli.display.warning')
+    def test_get_host_list_empty_inventory_error_off(self, mock_warning):
+        """Test that warning is displayed when ERROR_ON_EMPTY_INVENTORY is False and inventory is empty"""
+        self.mock_inventory.list_hosts.side_effect = [[], []]
+
+        result = cli.CLI.get_host_list(self.mock_inventory, None, 'webservers')
+
+        mock_warning.assert_called_once()
+        assert result == []