Add a way to prevent some actions from getting generated (#938)

Right now taskgraph always generates some generic actions that are used
on fxci on some projects. Projects that do not need to use said actions
are forced to add `rm actions.json` at the end of their decision task to
not get basic taskcluster features overridden by taskgraph
(rerun/retrigger mainly).

This adds a `disabled_actions` graph configuration that allows giving a
list of actions that should not be emitted in the actions.json.

Author: Eijebong

src/taskgraph/actions/registry.py

@@ -273,12 +273,27 @@ def render_actions_json(parameters, graph_config, decision_task_id):
             artifact.
     """
     assert isinstance(parameters, Parameters), "requires instance of Parameters"
+
+    all_actions = _get_actions(graph_config)
+    disabled = set(graph_config["taskgraph"].get("disabled-actions") or [])
+    known_cb_names = {action.cb_name for action in all_actions}
+    unknown = disabled - known_cb_names
+    if unknown:
+        raise ValueError(
+            "Unknown action(s) in `taskgraph.disabled-actions`: "
+            f"{sorted(unknown)}. Known actions: {sorted(known_cb_names)}"
+        )
+
     actions = []
-    for action in sorted(_get_actions(graph_config), key=lambda action: action.order):
+    for action in sorted(all_actions, key=lambda action: action.order):
+        if action.cb_name in disabled:
+            continue
+
         action = action.action_builder(parameters, graph_config, decision_task_id)
         if action:
             assert is_json(action), "action must be a JSON compatible object"
             actions.append(action)
+
     return {
         "version": 1,
         "variables": {},

src/taskgraph/config.py

@@ -57,6 +57,9 @@ class TaskgraphConfig(Schema):
     index_path_regexes: Optional[list[str]] = None
     # Configuration related to the 'run' transforms.
     run: Optional[RunConfig] = None
+    # List of action `cb_name`s to omit from `actions.json`,
+    # e.g. `["retrigger", "retrigger-disabled", "rerun"]`.
+    disabled_actions: Optional[list[str]] = None
 
     def __post_init__(self):
         # Validate repositories has at least 1 entry (was All(..., Length(min=1)))

test/test_actions_registry.py

@@ -4,6 +4,7 @@
 from mozilla_repo_urls import InvalidRepoUrlError
 
 from taskgraph.actions import registry
+from taskgraph.parameters import Parameters
 from test import does_not_raise
 
 
@@ -126,3 +127,75 @@ def test_sanity_check_task_scope(
     )
     with expectation:
         registry.sanity_check_task_scope(callback, parameters, graph_config={})
+
+
+def _make_action(cb_name):
+    return registry.Action(
+        order=42,
+        cb_name=cb_name,
+        permission="generic",
+        action_builder=lambda parameters, graph_config, decision_task_id: {
+            "cb_name": cb_name,
+        },
+    )
+
+
+@pytest.fixture
+def fake_actions(monkeypatch):
+    fake = [
+        _make_action("retrigger"),
+        _make_action("retrigger-disabled"),
+        _make_action("rerun"),
+        _make_action("cancel"),
+    ]
+    monkeypatch.setattr(registry, "_get_actions", lambda graph_config: fake)
+    return fake
+
+
+def _graph_config(disabled_actions):
+    taskgraph = {}
+    if disabled_actions is not None:
+        taskgraph["disabled-actions"] = disabled_actions
+    return {"taskgraph": taskgraph}
+
+
+def test_render_actions_json_no_disabled(fake_actions):
+    result = registry.render_actions_json(
+        Parameters(strict=False), _graph_config(None), "DECISION-TASK"
+    )
+    assert [a["cb_name"] for a in result["actions"]] == [
+        "retrigger",
+        "retrigger-disabled",
+        "rerun",
+        "cancel",
+    ]
+
+
+def test_render_actions_json_filters_disabled(fake_actions):
+    result = registry.render_actions_json(
+        Parameters(strict=False),
+        _graph_config(["retrigger", "retrigger-disabled", "rerun"]),
+        "DECISION-TASK",
+    )
+    assert [a["cb_name"] for a in result["actions"]] == ["cancel"]
+
+
+def test_render_actions_json_empty_disabled(fake_actions):
+    result = registry.render_actions_json(
+        Parameters(strict=False), _graph_config([]), "DECISION-TASK"
+    )
+    assert [a["cb_name"] for a in result["actions"]] == [
+        "retrigger",
+        "retrigger-disabled",
+        "rerun",
+        "cancel",
+    ]
+
+
+def test_render_actions_json_unknown_disabled_raises(fake_actions):
+    with pytest.raises(ValueError, match="does-not-exist"):
+        registry.render_actions_json(
+            Parameters(strict=False),
+            _graph_config(["retrigger", "does-not-exist"]),
+            "DECISION-TASK",
+        )