feat: Support deploying a single pipeline in a dataset (#46)

README.md

@@ -183,12 +183,15 @@ Deploy the DAG and the variables to your own Cloud Composer environment using on
 ```
 $ python scripts/deploy_dag.py \
   --dataset DATASET \
+  [--pipeline PIPELINE] \
   --composer-env CLOUD_COMPOSER_ENVIRONMENT_NAME \
   --composer-bucket CLOUD_COMPOSER_BUCKET \
   --composer-region CLOUD_COMPOSER_REGION \
   --env ENV
 ```
 
+The specifying an argument to `--pipeline` is optional. By default, the script deploys all pipelines under the given `--dataset` argument.
+
 # Testing
 
 Run the unit tests from the project root as follows:

scripts/deploy_dag.py

@@ -27,6 +27,7 @@ def main(
     local: bool,
     env_path: pathlib.Path,
     dataset_id: str,
+    pipeline: str = None,
     airflow_home: pathlib.Path = None,
     composer_env: str = None,
     composer_bucket: str = None,
@@ -41,7 +42,12 @@ def main(
     )
 
     print("========== AIRFLOW DAGS ==========")
-    for pipeline_path in list_subdirs(env_path / "datasets" / dataset_id):
+    if pipeline:
+        pipelines = [env_path / "datasets" / pipeline]
+    else:
+        pipelines = list_subdirs(env_path / "datasets" / dataset_id)
+
+    for pipeline_path in pipelines:
         copy_custom_callables_to_airflow_dags_folder(
             local,
             env_path,
@@ -326,6 +332,7 @@ def list_subdirs(path: pathlib.Path) -> typing.List[pathlib.Path]:
         local=args.local,
         env_path=PROJECT_ROOT / f".{args.env}",
         dataset_id=args.dataset,
+        pipeline=args.pipeline,
         airflow_home=airflow_path,
         composer_env=args.composer_env,
         composer_bucket=args.composer_bucket,

tests/scripts/test_deploy_dag.py

@@ -172,6 +172,51 @@ def test_script_always_requires_dataset_arg(
     )
 
 
+pipeline_path_2 = pipeline_path
+
+
+def test_script_with_pipeline_arg_deploys_only_that_pipeline(
+    dataset_path: pathlib.Path,
+    pipeline_path: pathlib.Path,
+    pipeline_path_2: pathlib.Path,
+    airflow_home: pathlib.Path,
+    env: str,
+):
+    setup_dag_and_variables(
+        dataset_path,
+        pipeline_path,
+        airflow_home,
+        env,
+        f"{dataset_path.name}_variables.json",
+    )
+
+    setup_dag_and_variables(
+        dataset_path,
+        pipeline_path_2,
+        airflow_home,
+        env,
+        f"{dataset_path.name}_variables.json",
+    )
+
+    deploy_dag.main(
+        local=True,
+        env_path=ENV_PATH,
+        dataset_id=dataset_path.name,
+        pipeline=pipeline_path_2.name,
+        airflow_home=airflow_home,
+        composer_env=None,
+        composer_bucket=None,
+        composer_region=None,
+    )
+
+    assert not (
+        airflow_home / "dags" / f"{dataset_path.name}__{pipeline_path.name}_dag.py"
+    ).exists()
+    assert (
+        airflow_home / "dags" / f"{dataset_path.name}__{pipeline_path_2.name}_dag.py"
+    ).exists()
+
+
 def test_script_without_local_flag_requires_cloud_composer_args(env: str):
     with pytest.raises(subprocess.CalledProcessError):
         # No --composer-env parameter