AIP-72: Support DAG parsing context in Task SDK (apache#45694)

Author: kaxil

Diff for: airflow/cli/commands/remote_commands/dag_command.py

@@ -37,9 +37,9 @@
 from airflow.jobs.job import Job
 from airflow.models import DagBag, DagModel, DagRun, TaskInstance
 from airflow.models.serialized_dag import SerializedDagModel
+from airflow.sdk.definitions._internal.dag_parsing_context import _airflow_parsing_context_manager
 from airflow.utils import cli as cli_utils, timezone
 from airflow.utils.cli import get_dag, process_subdir, suppress_logs_and_warning
-from airflow.utils.dag_parsing_context import _airflow_parsing_context_manager
 from airflow.utils.dot_renderer import render_dag, render_dag_dependencies
 from airflow.utils.helpers import ask_yesno
 from airflow.utils.providers_configuration_loader import providers_configuration_loaded

Diff for: airflow/task/standard_task_runner.py

@@ -33,10 +33,10 @@
 from airflow.configuration import conf
 from airflow.exceptions import AirflowConfigException
 from airflow.models.taskinstance import TaskReturnCode
+from airflow.sdk.definitions._internal.dag_parsing_context import _airflow_parsing_context_manager
 from airflow.settings import CAN_FORK
 from airflow.stats import Stats
 from airflow.utils.configuration import tmp_configuration_copy
-from airflow.utils.dag_parsing_context import _airflow_parsing_context_manager
 from airflow.utils.log.logging_mixin import LoggingMixin
 from airflow.utils.net import get_hostname
 from airflow.utils.platform import IS_WINDOWS, getuser

Diff for: airflow/utils/dag_parsing_context.py

@@ -14,47 +14,20 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
-from __future__ import annotations
-
-import os
-from contextlib import contextmanager
-from typing import NamedTuple
-
-
-class AirflowParsingContext(NamedTuple):
-    """
-    Context of parsing for the DAG.
-
-    If these values are not None, they will contain the specific DAG and Task ID that Airflow is requesting to
-    execute. You can use these for optimizing dynamically generated DAG files.
-    """
-
-    dag_id: str | None
-    task_id: str | None
 
+from __future__ import annotations
 
-_AIRFLOW_PARSING_CONTEXT_DAG_ID = "_AIRFLOW_PARSING_CONTEXT_DAG_ID"
-_AIRFLOW_PARSING_CONTEXT_TASK_ID = "_AIRFLOW_PARSING_CONTEXT_TASK_ID"
+import warnings
 
+from airflow.sdk.definitions.context import get_parsing_context
 
-@contextmanager
-def _airflow_parsing_context_manager(dag_id: str | None = None, task_id: str | None = None):
-    old_dag_id = os.environ.get(_AIRFLOW_PARSING_CONTEXT_DAG_ID)
-    old_task_id = os.environ.get(_AIRFLOW_PARSING_CONTEXT_TASK_ID)
-    if dag_id is not None:
-        os.environ[_AIRFLOW_PARSING_CONTEXT_DAG_ID] = dag_id
-    if task_id is not None:
-        os.environ[_AIRFLOW_PARSING_CONTEXT_TASK_ID] = task_id
-    yield
-    if old_task_id is not None:
-        os.environ[_AIRFLOW_PARSING_CONTEXT_TASK_ID] = old_task_id
-    if old_dag_id is not None:
-        os.environ[_AIRFLOW_PARSING_CONTEXT_DAG_ID] = old_dag_id
+# TODO: Remove this module in Airflow 3.2
 
+warnings.warn(
+    "Import from the airflow.utils.dag_parsing_context module is deprecated and "
+    "will be removed in Airflow 3.2. Please import it from 'airflow.sdk'.",
+    DeprecationWarning,
+    stacklevel=2,
+)
 
-def get_parsing_context() -> AirflowParsingContext:
-    """Return the current (DAG) parsing context info."""
-    return AirflowParsingContext(
-        dag_id=os.environ.get(_AIRFLOW_PARSING_CONTEXT_DAG_ID),
-        task_id=os.environ.get(_AIRFLOW_PARSING_CONTEXT_TASK_ID),
-    )
+__all__ = ["get_parsing_context"]

Diff for: docs/apache-airflow/howto/dynamic-dag-generation.rst

@@ -207,7 +207,7 @@ of the context are set to ``None``.
   :emphasize-lines: 4,8,9
 
   from airflow.models.dag import DAG
-  from airflow.utils.dag_parsing_context import get_parsing_context
+  from airflow.sdk import get_parsing_context
 
   current_dag_id = get_parsing_context().dag_id
 

Diff for: newsfragments/45694.significant.rst

@@ -0,0 +1,51 @@
+``get_parsing_context`` have been moved to Task SDK
+
+As part of AIP-72: Task SDK, the function ``get_parsing_context`` has been moved to ``airflow.sdk`` module.
+Previously, it was located in ``airflow.utils.dag_parsing_context`` module.
+
+This function is used to optimize DAG parsing during execution when DAGs are generated dynamically.
+
+Before:
+
+.. code-block:: python
+
+    from airflow.models.dag import DAG
+    from airflow.utils.dag_parsing_context import get_parsing_context
+
+    current_dag_id = get_parsing_context().dag_id
+
+    for thing in list_of_things:
+        dag_id = f"generated_dag_{thing}"
+        if current_dag_id is not None and current_dag_id != dag_id:
+            continue  # skip generation of non-selected DAG
+
+        with DAG(dag_id=dag_id, ...):
+            ...
+
+After:
+
+.. code-block:: python
+
+    from airflow.sdk import get_parsing_context
+
+    current_dag_id = get_parsing_context().dag_id
+
+    # The rest of the code remains the same
+
+* Types of change
+
+  * [x] DAG changes
+  * [ ] Config changes
+  * [ ] API changes
+  * [ ] CLI changes
+  * [ ] Behaviour changes
+  * [ ] Plugin changes
+  * [ ] Dependency change
+
+* Migration rules needed
+
+  * ruff
+
+    * AIR302
+
+      * [ ] ``airflow.utils.dag_parsing_context.get_parsing_context`` -> ``airflow.sdk.get_parsing_context``

Diff for: providers/src/airflow/providers/celery/executors/celery_executor_utils.py

@@ -44,8 +44,8 @@
 from airflow.configuration import conf
 from airflow.exceptions import AirflowException, AirflowProviderDeprecationWarning, AirflowTaskTimeout
 from airflow.executors.base_executor import BaseExecutor
+from airflow.sdk.definitions._internal.dag_parsing_context import _airflow_parsing_context_manager
 from airflow.stats import Stats
-from airflow.utils.dag_parsing_context import _airflow_parsing_context_manager
 from airflow.utils.log.logging_mixin import LoggingMixin
 from airflow.utils.net import get_hostname
 from airflow.utils.providers_configuration_loader import providers_configuration_loaded

Diff for: scripts/cov/core_coverage.py

@@ -104,7 +104,6 @@
     "airflow/utils/code_utils.py",
     "airflow/utils/context.py",
     "airflow/utils/dag_cycle_tester.py",
-    "airflow/utils/dag_parsing_context.py",
     "airflow/utils/dates.py",
     "airflow/utils/db.py",
     "airflow/utils/db_cleanup.py",

Diff for: task_sdk/src/airflow/sdk/__init__.py

@@ -27,6 +27,7 @@
     "dag",
     "Connection",
     "get_current_context",
+    "get_parsing_context",
     "__version__",
 ]
 
@@ -35,7 +36,7 @@
 if TYPE_CHECKING:
     from airflow.sdk.definitions.baseoperator import BaseOperator
     from airflow.sdk.definitions.connection import Connection
-    from airflow.sdk.definitions.context import get_current_context
+    from airflow.sdk.definitions.context import get_current_context, get_parsing_context
     from airflow.sdk.definitions.dag import DAG, dag
     from airflow.sdk.definitions.edges import EdgeModifier, Label
     from airflow.sdk.definitions.taskgroup import TaskGroup
@@ -50,6 +51,7 @@
     "Connection": ".definitions.connection",
     "Variable": ".definitions.variable",
     "get_current_context": ".definitions.context",
+    "get_parsing_context": ".definitions.context",
 }
 
 

Diff for: task_sdk/src/airflow/sdk/definitions/_internal/dag_parsing_context.py

@@ -0,0 +1,37 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+from __future__ import annotations
+
+import os
+from contextlib import contextmanager
+
+from airflow.sdk.definitions.context import _AIRFLOW_PARSING_CONTEXT_DAG_ID, _AIRFLOW_PARSING_CONTEXT_TASK_ID
+
+
+@contextmanager
+def _airflow_parsing_context_manager(dag_id: str | None = None, task_id: str | None = None):
+    old_dag_id = os.environ.get(_AIRFLOW_PARSING_CONTEXT_DAG_ID)
+    old_task_id = os.environ.get(_AIRFLOW_PARSING_CONTEXT_TASK_ID)
+    if dag_id is not None:
+        os.environ[_AIRFLOW_PARSING_CONTEXT_DAG_ID] = dag_id
+    if task_id is not None:
+        os.environ[_AIRFLOW_PARSING_CONTEXT_TASK_ID] = task_id
+    yield
+    if old_task_id is not None:
+        os.environ[_AIRFLOW_PARSING_CONTEXT_TASK_ID] = old_task_id
+    if old_dag_id is not None:
+        os.environ[_AIRFLOW_PARSING_CONTEXT_DAG_ID] = old_dag_id

Diff for: task_sdk/src/airflow/sdk/definitions/context.py

@@ -17,7 +17,8 @@
 # under the License.
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Any, TypedDict
+import os
+from typing import TYPE_CHECKING, Any, NamedTuple, TypedDict
 
 if TYPE_CHECKING:
     # TODO: Should we use pendulum.DateTime instead of datetime like AF 2.x?
@@ -105,3 +106,27 @@ def my_task():
     from airflow.sdk.definitions._internal.contextmanager import _get_current_context
 
     return _get_current_context()
+
+
+class AirflowParsingContext(NamedTuple):
+    """
+    Context of parsing for the DAG.
+
+    If these values are not None, they will contain the specific DAG and Task ID that Airflow is requesting to
+    execute. You can use these for optimizing dynamically generated DAG files.
+    """
+
+    dag_id: str | None
+    task_id: str | None
+
+
+_AIRFLOW_PARSING_CONTEXT_DAG_ID = "_AIRFLOW_PARSING_CONTEXT_DAG_ID"
+_AIRFLOW_PARSING_CONTEXT_TASK_ID = "_AIRFLOW_PARSING_CONTEXT_TASK_ID"
+
+
+def get_parsing_context() -> AirflowParsingContext:
+    """Return the current (DAG) parsing context info."""
+    return AirflowParsingContext(
+        dag_id=os.environ.get(_AIRFLOW_PARSING_CONTEXT_DAG_ID),
+        task_id=os.environ.get(_AIRFLOW_PARSING_CONTEXT_TASK_ID),
+    )

Diff for: task_sdk/src/airflow/sdk/execution_time/task_runner.py

@@ -33,6 +33,7 @@
 
 from airflow.dag_processing.bundles.manager import DagBundlesManager
 from airflow.sdk.api.datamodels._generated import TaskInstance, TerminalTIState, TIRunContext
+from airflow.sdk.definitions._internal.dag_parsing_context import _airflow_parsing_context_manager
 from airflow.sdk.definitions.baseoperator import BaseOperator
 from airflow.sdk.execution_time.comms import (
     DeferTask,
@@ -406,8 +407,8 @@ def startup() -> tuple[RuntimeTaskInstance, Logger]:
         setproctitle(f"airflow worker -- {msg.ti.id}")
 
         log = structlog.get_logger(logger_name="task")
-        # TODO: set the "magic loop" context vars for parsing
-        ti = parse(msg)
+        with _airflow_parsing_context_manager(dag_id=msg.ti.dag_id, task_id=msg.ti.task_id):
+            ti = parse(msg)
         log.debug("DAG file parsed", file=msg.dag_rel_path)
     else:
         raise RuntimeError(f"Unhandled  startup message {type(msg)} {msg}")

Diff for: task_sdk/tests/dags/dag_parsing_context.py

@@ -0,0 +1,36 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+from __future__ import annotations
+
+from datetime import datetime
+
+from airflow.sdk import DAG, BaseOperator, get_parsing_context
+
+DAG_ID = "dag_parsing_context_test"
+
+current_dag_id = get_parsing_context().dag_id
+
+with DAG(
+    DAG_ID,
+    start_date=datetime(2024, 2, 21),
+    schedule=None,
+) as the_dag:
+    BaseOperator(task_id="visible_task")
+
+    if current_dag_id == DAG_ID:
+        # this task will be invisible if the DAG ID is not properly set in the parsing context.
+        BaseOperator(task_id="conditional_task")

Diff for: task_sdk/tests/execution_time/test_task_runner.py

@@ -542,6 +542,46 @@ def execute(self, context):
     )
 
 
+def test_dag_parsing_context(make_ti_context, mock_supervisor_comms, monkeypatch, test_dags_dir):
+    """
+    Test that the DAG parsing context is correctly set during the startup process.
+
+    This test verifies that the DAG and task IDs are correctly set in the parsing context
+    when a DAG is started up.
+    """
+    dag_id = "dag_parsing_context_test"
+    task_id = "conditional_task"
+
+    what = StartupDetails(
+        ti=TaskInstance(id=uuid7(), task_id=task_id, dag_id=dag_id, run_id="c", try_number=1),
+        dag_rel_path="dag_parsing_context.py",
+        bundle_info=BundleInfo(name="my-bundle", version=None),
+        requests_fd=0,
+        ti_context=make_ti_context(dag_id=dag_id, run_id="c"),
+    )
+
+    mock_supervisor_comms.get_message.return_value = what
+
+    # Set the environment variable for DAG bundles
+    # We use the DAG defined in `task_sdk/tests/dags/dag_parsing_context.py` for this test!
+    dag_bundle_val = json.dumps(
+        [
+            {
+                "name": "my-bundle",
+                "classpath": "airflow.dag_processing.bundles.local.LocalDagBundle",
+                "kwargs": {"local_folder": str(test_dags_dir), "refresh_interval": 1},
+            }
+        ]
+    )
+
+    monkeypatch.setenv("AIRFLOW__DAG_BUNDLES__BACKENDS", dag_bundle_val)
+    ti, _ = startup()
+
+    # Presence of `conditional_task` below means DAG ID is properly set in the parsing context!
+    # Check the dag file for the actual logic!
+    assert ti.task.dag.task_dict.keys() == {"visible_task", "conditional_task"}
+
+
 class TestRuntimeTaskInstance:
     def test_get_context_without_ti_context_from_server(self, mocked_parse, make_ti_context):
         """Test get_template_context without ti_context_from_server."""

Diff for: tests/dags/test_dag_parsing_context.py

@@ -20,7 +20,7 @@
 
 from airflow.models.dag import DAG
 from airflow.operators.empty import EmptyOperator
-from airflow.utils.dag_parsing_context import get_parsing_context
+from airflow.sdk.definitions.context import get_parsing_context
 
 DAG_ID = "test_dag_parsing_context"
 

Diff for: tests/dags/test_parsing_context.py

@@ -18,19 +18,16 @@
 from __future__ import annotations
 
 from pathlib import Path
-from typing import TYPE_CHECKING
 
 from airflow.models.dag import DAG
 from airflow.operators.empty import EmptyOperator
-from airflow.utils.dag_parsing_context import (
+from airflow.sdk.definitions.context import (
     _AIRFLOW_PARSING_CONTEXT_DAG_ID,
     _AIRFLOW_PARSING_CONTEXT_TASK_ID,
+    Context,
 )
 from airflow.utils.timezone import datetime
 
-if TYPE_CHECKING:
-    from airflow.sdk.definitions.context import Context
-
 
 class DagWithParsingContext(EmptyOperator):
     def execute(self, context: Context):