Add option to allow running with missing plugins and collection depen…

…dencies (#3913)

.github/workflows/tox.yml

@@ -70,7 +70,7 @@ jobs:
     env:
       # Number of expected test passes, safety measure for accidental skip of
       # tests. Update value if you add/remove tests.
-      PYTEST_REQPASS: 845
+      PYTEST_REQPASS: 847
     steps:
       - uses: actions/checkout@v4
         with:

examples/playbooks/nodeps.yml

@@ -0,0 +1,6 @@
+---
+- name: Example
+  hosts: localhost
+  tasks:
+    - name: Calling a module that is not installed
+      a.b.c: {}

examples/playbooks/nodeps2.yml

@@ -0,0 +1,7 @@
+---
+- name: Fixture for nodeps with missing filter
+  hosts: localhost
+  tasks:
+    - name: Calling a module that is not installed
+      ansible.builtin.debug:
+        msg: "{{ foo | missing_filter }}"

src/ansiblelint/__main__.py

@@ -318,6 +318,7 @@ def main(argv: list[str] | None = None) -> int:
             ),
         )
         or options.offline
+        or options.nodeps
     )
 
     if not skip_schema_update:

src/ansiblelint/config.py

@@ -173,6 +173,12 @@ class Options:  # pylint: disable=too-many-instance-attributes
     ignore_file: Path | None = None
     max_tasks: int = 100
     max_block_depth: int = 20
+    nodeps: bool = bool(int(os.environ.get("ANSIBLE_LINT_NODEPS", "0")))
+
+    def __post_init__(self) -> None:
+        """Extra initialization logic."""
+        if self.nodeps:
+            self.offline = True
 
 
 options = Options()

src/ansiblelint/constants.py

@@ -13,6 +13,7 @@
     "ANSIBLE_LINT_IGNORE_FILE": "Define it to override the name of the default ignore file `.ansible-lint-ignore`",
     "ANSIBLE_LINT_WRITE_TMP": "Tells linter to dump fixes into different temp files instead of overriding original. Used internally for testing.",
     SKIP_SCHEMA_UPDATE: "Tells ansible-lint to skip schema refresh.",
+    "ANSIBLE_LINT_NODEPS": "Avoids installing content dependencies and avoids performing checks that would fail when modules are not installed. Far less violations will be reported.",
 }
 
 EPILOG = (

src/ansiblelint/rules/syntax_check.md

@@ -9,7 +9,7 @@ You can exclude these files from linting, but it is better to make sure they can
 be loaded by Ansible. This is often achieved by editing the inventory file
 and/or `ansible.cfg` so ansible can load required variables.
 
-If undefined variables cause the failure, you can use the jinja `default()`
+If undefined variables cause the failure, you can use the Jinja `default()`
 filter to provide fallback values, like in the example below.
 
 This rule is among the few `unskippable` rules that cannot be added to
@@ -20,9 +20,13 @@ fixtures that are invalid on purpose.
 One of the most common sources of errors is a failure to assert the presence of
 various variables at the beginning of the playbook.
 
-This rule can produce messages like below:
+This rule can produce messages like:
 
-- `syntax-check[empty-playbook]` is raised when a playbook file has no content.
+- `syntax-check[empty-playbook]`: Empty playbook, nothing to do
+- `syntax-check[malformed]`: A malformed block was encountered while loading a block
+- `syntax-check[missing-file]`: Unable to retrieve file contents ... Could not find or access ...
+- `syntax-check[unknown-module]`: couldn't resolve module/action
+- `syntax-check[specific]`: for other errors not mentioned above.
 
 ## Problematic code
 

src/ansiblelint/rules/syntax_check.py

@@ -15,6 +15,8 @@ class KnownError:
     regex: re.Pattern[str]
 
 
+# Order matters, we only report the first matching pattern, the one at the end
+# is used to match generic or less specific patterns.
 OUTPUT_PATTERNS = (
     KnownError(
         tag="missing-file",
@@ -25,23 +27,30 @@ class KnownError:
         ),
     ),
     KnownError(
-        tag="specific",
+        tag="empty-playbook",
         regex=re.compile(
-            r"^ERROR! (?P<title>[^\n]*)\n\nThe error appears to be in '(?P<filename>[\w\/\.\-]+)': line (?P<line>\d+), column (?P<column>\d+)",
+            "Empty playbook, nothing to do",
             re.MULTILINE | re.S | re.DOTALL,
         ),
     ),
     KnownError(
-        tag="empty-playbook",
+        tag="malformed",
         regex=re.compile(
-            "Empty playbook, nothing to do",
+            "^ERROR! (?P<title>A malformed block was encountered while loading a block[^\n]*)",
             re.MULTILINE | re.S | re.DOTALL,
         ),
     ),
     KnownError(
-        tag="malformed",
+        tag="unknown-module",
         regex=re.compile(
-            "^ERROR! (?P<title>A malformed block was encountered while loading a block[^\n]*)",
+            r"^ERROR! (?P<title>couldn't resolve module/action [^\n]*)\n\nThe error appears to be in '(?P<filename>[\w\/\.\-]+)': line (?P<line>\d+), column (?P<column>\d+)",
+            re.MULTILINE | re.S | re.DOTALL,
+        ),
+    ),
+    KnownError(
+        tag="specific",
+        regex=re.compile(
+            r"^ERROR! (?P<title>[^\n]*)\n\nThe error appears to be in '(?P<filename>[\w\/\.\-]+)': line (?P<line>\d+), column (?P<column>\d+)",
             re.MULTILINE | re.S | re.DOTALL,
         ),
     ),

src/ansiblelint/runner.py

@@ -372,6 +372,7 @@ def _get_ansible_syntax_check_matches(
             filename = lintable
             lineno = 1
             column = None
+            ignore_rc = False
 
             stderr = strip_ansi_escape(run.stderr)
             stdout = strip_ansi_escape(run.stdout)
@@ -396,19 +397,24 @@ def _get_ansible_syntax_check_matches(
                     else:
                         filename = lintable
                     column = int(groups.get("column", 1))
-                    results.append(
-                        MatchError(
-                            message=title,
-                            lintable=filename,
-                            lineno=lineno,
-                            column=column,
-                            rule=rule,
-                            details=details,
-                            tag=f"{rule.id}[{pattern.tag}]",
-                        ),
-                    )
-
-            if not results:
+
+                    if pattern.tag == "unknown-module" and app.options.nodeps:
+                        ignore_rc = True
+                    else:
+                        results.append(
+                            MatchError(
+                                message=title,
+                                lintable=filename,
+                                lineno=lineno,
+                                column=column,
+                                rule=rule,
+                                details=details,
+                                tag=f"{rule.id}[{pattern.tag}]",
+                            ),
+                        )
+                    break
+
+            if not results and not ignore_rc:
                 rule = self.rules["internal-error"]
                 message = (
                     f"Unexpected error code {run.returncode} from "

test/test_examples.py

@@ -23,9 +23,9 @@ def test_example(default_rules_collection: RulesCollection) -> None:
             "examples/playbooks/syntax-error-string.yml",
             6,
             7,
-            id="syntax-error",
+            id="0",
         ),
-        pytest.param("examples/playbooks/syntax-error.yml", 2, 3, id="syntax-error"),
+        pytest.param("examples/playbooks/syntax-error.yml", 2, 3, id="1"),
     ),
 )
 def test_example_syntax_error(

test/test_main.py

@@ -82,3 +82,25 @@ def test_get_version_warning(
     else:
         assert check in msg
     assert len(msg.split("\n")) == outlen
+
+
+@pytest.mark.parametrize(
+    ("lintable"),
+    (
+        pytest.param("examples/playbooks/nodeps.yml", id="1"),
+        pytest.param("examples/playbooks/nodeps2.yml", id="2"),
+    ),
+)
+def test_nodeps(lintable: str) -> None:
+    """Asserts ability to be called w/ or w/o venv activation."""
+    env = os.environ.copy()
+    env["ANSIBLE_LINT_NODEPS"] = "1"
+    py_path = Path(sys.executable).parent
+    proc = subprocess.run(
+        [str(py_path / "ansible-lint"), lintable],
+        check=False,
+        capture_output=True,
+        text=True,
+        env=env,
+    )
+    assert proc.returncode == 0, proc