Make current working directory as templated field in BashOperator (#3…

…7928)

* Make current working directory as templated field in BashOperator

* Update airflow/operators/bash.py

Co-authored-by: Tzu-ping Chung <uranusjr@gmail.com>

---------

Co-authored-by: Tzu-ping Chung <uranusjr@gmail.com>

airflow/operators/bash.py

@@ -59,8 +59,10 @@ class BashOperator(BaseOperator):
     :param skip_on_exit_code: If task exits with this exit code, leave the task
         in ``skipped`` state (default: 99). If set to ``None``, any non-zero
         exit code will be treated as a failure.
-    :param cwd: Working directory to execute the command in.
+    :param cwd: Working directory to execute the command in (templated).
         If None (default), the command is run in a temporary directory.
+        To use current DAG folder as the working directory,
+        you might set template ``{{ dag_run.dag.folder }}``.
 
     Airflow will evaluate the exit code of the Bash command. In general, a non-zero exit code will result in
     task failure and zero will result in task success.
@@ -130,7 +132,7 @@ class BashOperator(BaseOperator):
 
     """
 
-    template_fields: Sequence[str] = ("bash_command", "env")
+    template_fields: Sequence[str] = ("bash_command", "env", "cwd")
     template_fields_renderers = {"bash_command": "bash", "env": "json"}
     template_ext: Sequence[str] = (".sh", ".bash")
     ui_color = "#f0ede4"

tests/operators/test_bash.py

@@ -20,6 +20,7 @@
 import os
 import signal
 from datetime import datetime, timedelta
+from pathlib import Path
 from time import sleep
 from unittest import mock
 
@@ -244,3 +245,22 @@ def test_bash_operator_kill(self, dag_maker):
                 os.kill(proc.pid, signal.SIGTERM)
                 assert False, "BashOperator's subprocess still running after stopping on timeout!"
                 break
+
+    @pytest.mark.db_test
+    def test_templated_fields(self, create_task_instance_of_operator):
+        ti = create_task_instance_of_operator(
+            BashOperator,
+            # Templated fields
+            bash_command='echo "{{ dag_run.dag_id }}"',
+            env={"FOO": "{{ ds }}"},
+            cwd="{{ dag_run.dag.folder }}",
+            # Other parameters
+            dag_id="test_templated_fields_dag",
+            task_id="test_templated_fields_task",
+            execution_date=timezone.datetime(2024, 2, 1, tzinfo=timezone.utc),
+        )
+        ti.render_templates()
+        task: BashOperator = ti.task
+        assert task.bash_command == 'echo "test_templated_fields_dag"'
+        assert task.env == {"FOO": "2024-02-01"}
+        assert task.cwd == Path(__file__).absolute().parent.as_posix()