pipeline.yaml

# Copyright 2021 Google LLC
#
# Licensed 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.


---
resources:
  # A list of GCP resources that are unique and specific to your pipeline.
  #
  # The currently supported resources are shown below. Use only the resources
  # needed by your pipeline, and delete the rest of the examples.
  #
  # We will keep adding to the list below to support more Google Cloud resources
  # over time. If a resource you need isn't supported, please file an issue on
  # the repository.

  - type: bigquery_table
    # A Google BigQuery table to store your data. Requires a `bigquery_dataset`
    # to be specified in the config (i.e. `dataset.yaml) for the dataset that
    # this pipeline belongs in.
    #
    # Required Properties:
    #   table_id
    table_id: PIPELINE_FOLDER_NAME

    # Optional Properties:
    # Description of the table
    description: "This is a table description."

    # Time-based partitioning configuration. There is no need for this property
    # if you have a relatively small dataset to host on a BigQuery table.
    time_partitioning:

      # The supported types are DAY, HOUR, MONTH, and YEAR, which will generate one partition per day, hour, month, and year, respectively.
      type: "DAY"

      # If set to true, queries over this table require a partition filter that can be used for partition elimination to be specified.
      require_partition_filter: false

    # Specifies column names to use for data clustering. Up to four top-level columns are allowed, and should be specified in descending priority order.
    clustering:
      - "column_1"
      - "column_2"
      - "column_3"

    # The table cannot be deleted without first disabling this property.
    # Unless this field is set to false in Terraform state, a `terraform destroy`
    # or `terraform apply` that would delete the table will fail.
    deletion_protection: true

dag:
  # [Required] Specify the Airflow version of the operators used by the DAG.
  airflow_version: 2

  # The DAG acronym stands for directed acyclic graph. This block represents
  # your data pipeline along with every property and configuration it needs to
  # onboard your data.
  initialize:
    dag_id: PIPELINE_FOLDER_NAME
    default_args:
      owner: "Google"

      # When set to True, keeps a task from getting triggered if the previous schedule for the task hasn’t succeeded
      depends_on_past: False
      start_date: '2021-03-01'
    max_active_runs: 1
    schedule_interval: "@once"
    catchup: False
    default_view: graph

  tasks:
    # This is where you specify the tasks (a.k.a. processes) that your data
    # pipeline will run to onboard the data.
    #
    # As the examples below will show, every task must be represented by an
    # Airflow operator. The list of suported operators are listed in
    #
    #   scripts/dag_imports.json
    #
    # If an operator you need isn't supported, please file an issue on the
    # repository.
    #
    # Use the YAML list syntax in this block to specify every task for your
    # pipeline.

    - operator: "BashOperator"
      # Initializes an Airflow BashOperator for the DAG. This operator can be
      # used to
      # - Download from HTTP sources
      # - Run custom Python scripts
      # - Run processes using specific packages that support CLI commands

      # Task description
      description: "Run a custom Python script"

      args:
        # Arguments supported by this operator:
        # https://airflow.apache.org/docs/apache-airflow/stable/howto/operator/bash.html

        task_id: "sample_bash_task"
        bash_command: |
          mkdir -p $airflow_home/data/$dataset/$pipeline/run_date={{ ds }}
          CUSTOM_ENV_VAR=$custom_env_var python $airflow_home/dags/$dataset/$pipeline/custom/some_script.py
        env:
          airflow_home: "{{ var.value.airflow_home }}"
          dataset: DATASET_FOLDER_NAME
          pipeline: PIPELINE_FOLDER_NAME
          custom_env_var: "some value that your custom script needs"

    - operator: "GoogleCloudStorageToBigQueryOperator"
      # Initializes GCS to BQ task for the DAG. This operator is used to load a
      # JSON, CSV, Avro, ORC, or Parquet data from GCS into a BigQuery table.

      # Task description
      description: "Task to load CSV data to a BigQuery table"

      # Arguments supported by this operator:
      # http://airflow.apache.org/docs/apache-airflow/stable/howto/operator/gcp/gcs.html#googlecloudstoragetobigqueryoperator
      args:
        task_id: "sample_gcs_to_bq_task"

        # The GCS bucket where the CSV file is located in.
        bucket: "{{ var.value.composer_bucket }}"

        # The GCS object path for the CSV file
        source_objects: ["data/DATASET_FOLDER_NAME/PIPELINE_FOLDER_NAME/run_date={{ ds }}/data.csv"]
        source_format: "CSV"
        destination_project_dataset_table: "DATASET_FOLDER_NAME.PIPELINE_FOLDER_NAME"

        # Use this if your CSV file contains a header row
        skip_leading_rows: 1

        # How to write data to the table: overwrite, append, or write if empty
        # See https://cloud.google.com/bigquery/docs/reference/auditlogs/rest/Shared.Types/WriteDisposition
        write_disposition: "WRITE_TRUNCATE"

        # The BigQuery table schema based on the CSV file. For more info, see
        # https://cloud.google.com/bigquery/docs/schemas.
        # Always use snake_case and lowercase for column names, and be explicit,
        # i.e. specify modes for all columns.
        schema_fields:
          - name: "name"
            type: "STRING"
            mode: "REQUIRED"
          - name: "string_col"
            type: "STRING"
            mode: "NULLABLE"
          - name: "date"
            type: "DATE"
            mode: "REQUIRED"
          - name: "num_col"
            type: "INTEGER"
            mode: "NULLABLE"

    # Copies objects from a bucket to another using the Google Cloud Storage Transfer Service.
    # This operator does not control the copying process locally, but uses Google resources, which allows them to perform this task faster and more economically.
    #
    # Warning: This operator is NOT idempotent. If you run it many times, many transfer jobs will be created in the Google Cloud.
    - operator: "CloudDataTransferServiceGCSToGCSOperator"

      # Task description
      description: "Task to run a GCS to GCS operation using the Cloud Data Transfer Service"

      # Arguments supported by this operator:
      # https://airflow.apache.org/docs/apache-airflow-providers-google/stable/_api/airflow/providers/google/cloud/operators/cloud_storage_transfer_service/index.html#airflow.providers.google.cloud.operators.cloud_storage_transfer_service.CloudDataTransferServiceGCSToGCSOperator
      args:
        task_id: "sample_data_transfer_service_gcs_to_gcs"
        project_id: "{{ var.value.gcp_project }}"

        # The GCS bucket to copy from
        source_bucket: "sample-source-bucket"

        # The GCS bucket to copy to
        destination_bucket: "sample-destination-bucket"

        # The service account to use that have been granted read access to the source bucket
        google_impersonation_chain: "gcp-service-account@sample-project.iam.gserviceaccount.com"

    # Initializes a GCS-to-GCS task for the DAG. This operator is used to copy or move
    # GCS objects from one location to another.
    - operator: "GoogleCloudStorageToGoogleCloudStorageOperator"

      # Task description
      description: "Task to run a GoogleCloudStorageToGoogleCloudStorageOperator"

      args:
        # Arguments supported by this operator:
        # https://airflow.apache.org/docs/apache-airflow-providers-google/stable/_api/airflow/providers/google/cloud/transfers/gcs_to_gcs/index.html

        task_id: "sample_gcs_to_gcs_task"

        # The GCS bucket to copy the object/s from
        source_bucket: "{{ var.value.composer_bucket }}"

        # Use a trailing "/*" if you want to copy all objects under that path.
        source_object: "data/DATASET_FOLDER_NAME/PIPELINE_FOLDER_NAME/run_date={{ ds }}/*"

        # Optionally, you can supply a list of objects to specifically copy
        source_objects:
          - "path/to/object"
          - "path/to/another/object"

        # The GCS bucket to copy the object/s to
        destination_bucket: "{{ var.json.DATASET_FOLDER_NAME.destination_bucket }}"

        # The GCS prefix to copy the object/s to
        destination_object: "datasets/DATASET_FOLDER_NAME/PIPELINE_FOLDER_NAME/run_date={{ ds }}/"

        # Use this argument if you don't want to keep the source object/s.
        move_object: True

        # Whether you want to replace existing destination files or not.
        replace: False

        # [Optional] This is used to restrict the result to only the matching names in a given folder
        # If source_objects = ['foo/bah/'] and delimiter = '.avro', then only the .avro
        # files will be copied to the destination folder.
        delimiter: ".csv"

        # [Optional] When specified, the objects will be copied or moved, only if they were modified
        # after last_modified_time. If tzinfo has not been set, UTC will be assumed.
        last_modified_time: "2021-08-10 11:58:27"

    - operator: "BigQueryExecuteQueryOperator"
      # Initializes a BigQuery operator that executes SQL queries in a specific BigQuery table,
      # and can optionally store the results of a query to another table

      # Task description
      description: "Task to run a execute a BigQuery SQL query in a specific BigQuery database"

      args:
        # Arguments supported by this operator:
        # https://airflow.apache.org/docs/apache-airflow-providers-google/stable/_api/airflow/providers/google/cloud/operators/bigquery/index.html#airflow.providers.google.cloud.operators.bigquery.BigQueryExecuteQueryOperator

        task_id: "sample_bq_sql_task"

        # The SQL query to execute, along with query parameters. For more info,
        # see https://cloud.google.com/bigquery/docs/parameterized-queries.
        sql: "SELECT * FROM DATASET_FOLDER_NAME.PIPELINE_FOLDER_NAME LIMIT @max_rows"
        query_params:
          - name: "max_rows"
            parameterType:
              type: "INTEGER"
            parameterValue:
              value: 100

        # If specified, will store the results of the query to a BigQuery destination table
        destination_dataset_table: "destination_dataset.destination_table"

        # Specifies whether the job is allowed to create new tables.
        create_disposition: "CREATE_IF_NEEDED"

        # How to write to the destination: overwrite, append, or write if empty
        # See https://cloud.google.com/bigquery/docs/reference/auditlogs/rest/Shared.Types/WriteDisposition
        write_disposition: "WRITE_TRUNCATE"

        # [Optional] Configure optional time partitioning fields i.e. partition by field, type and expiration
        # as per API specifications.
        time_partitioning:
          # The supported types are DAY, HOUR, MONTH, and YEAR, which will generate one partition per day, hour,
          # month, and year, respectively.
          type: "DAY"

        # [Optional] BigQuery supports clustering for both partitioned and non-partitioned tables. The order
        # of columns given determines the sort order.
        cluster_fields:
          - "column_1"
          - "column_2"
          - "column_3"

        # [Optional for US and EU] The geographic location of the job
        location: "asia-northeast1"

    # Deletes objects from a Google Cloud Storage bucket, either from an explicit list of object names
    # or all objects matching a prefix.
    - operator: "GoogleCloudStorageDeleteOperator"

      # Task description
      description: "Task to delete objects from a GCS bucket"

      # Arguments supported by this operator:
      # https://airflow.apache.org/docs/apache-airflow-providers-google/stable/_api/airflow/providers/google/cloud/operators/gcs/index.html#airflow.providers.google.cloud.operators.gcs.GCSDeleteObjectsOperator
      args:
        task_id: "gcs_delete_task"

        # The GCS bucket where the objects to delete are located.
        bucket_name: "sample_bucket"

        # List of objects to delete. These should be the names of objects in the bucket, not including gs://bucket/.
        objects: ["path/to/some_object"]

        # Alternatively, you can specify a prefix of objects to delete.
        # All objects matching this prefix in the bucket will be deleted.
        prefix: "prefix/to/delete"

    # Executes a task in a Kubernetes pod that uses the Cloud Composer environment's own CPU and memory resources.
    # Note: Do NOT use this for very heavy workloads. This can potentially starve resources from Cloud Composer
    # and affect data pipeline orchestration overall. Instead, use a different GKE cluster using Kubernetes
    # Engine operators: https://github.com/apache/airflow/blob/master/airflow/providers/google/cloud/operators/kubernetes_engine.py
    - operator: "KubernetesPodOperator"

      # Task description
      description: "Task to run a KubernetesPodOperator"

      args:
        # Arguments supported by this operator:
        # https://airflow.readthedocs.io/en/1.10.15/_api/airflow/contrib/operators/kubernetes_pod_operator/index.html#airflow.contrib.operators.kubernetes_pod_operator.KubernetesPodOperator

        task_id: "sample_kube_pod_operator"

        # The name of the pod in which the task will run. This will be used (plus a random suffix) to generate a pod id
        name: "sample-kube-operator"

        # The namespace to run within Kubernetes. Always set its value to "default" because we follow the guideline that KubernetesPodOperator will only be used for very light workloads, i.e. use the Cloud Composer environment's resources without starving other pipelines.
        namespace: "default"

        # Use this attribute to constrain which node pools your pod must run in.
        affinity:
          nodeAffinity:
            requiredDuringSchedulingIgnoredDuringExecution:
              nodeSelectorTerms:
                - matchExpressions:
                    - key: cloud.google.com/gke-nodepool
                      operator: In
                      values:  # Specify your node pools here
                        - "pool-e2-standard-4"

        # The Google Container Registry image URL. To prepare a Docker image to be used by this operator:
        #
        # 1. Create an `_images` folder under your dataset folder if it doesn't exist.
        #
        # 2. Inside the `_images` folder, create another folder and name it after what the image is expected to do, e.g. process_shapefiles, get_cdf_metadata.
        #
        # 3. In that subfolder, create a Dockerfile (https://docs.docker.com/engine/reference/builder/) and any scripts you need to process the data. Use the `COPY` command (https://docs.docker.com/engine/reference/builder/#copy) in your `Dockerfile` to include your scripts in the image.
        #
        # The resulting file tree for a dataset that uses two container images may look like
        #
        #   datasets
        #   └── DATASET
        #       ├── _images
        #       │   ├── container_a
        #       │   │   ├── Dockerfile
        #       │   │   ├── requirements.txt
        #       │   │   └── script.py
        #       │   └── container_b
        #       │       ├── Dockerfile
        #       │       ├── requirements.txt
        #       │       └── script.py
        #       ├── _terraform/
        #       ├── PIPELINE_A
        #       ├── PIPELINE_B
        #       ├── ...
        #       └── dataset.yaml
        #
        # Docker images will be built and pushed to GCR by default whenever the `scripts/generate_dag.py` is run. To skip building and pushing images, use the optional `--skip-builds` flag.
        image: "{{ var.json.DATASET_FOLDER_NAME.container_registry.IMAGE_REPOSITORY }}"

        # Always pull the latest image. We recommend to keep this as "Always".
        image_pull_policy: "Always"

        # Set the environment variables you need initialized in the container. Use these as input variables for the script your container is expected to perform.
        env_vars:
          TEST_ENV_VAR: "test-value"
          ANOTHER_ENV_VAR: 12345

        # Set resource limits for the pod here. For resource units in Kubernetes, see https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#resource-units-in-kubernetes
        resources:
          limit_memory: "250M"
          limit_cpu: "1"

    # Documentation:
    # http://airflow.apache.org/docs/apache-airflow-providers-google/stable/_api/airflow/providers/google/cloud/operators/kubernetes_engine/index.html#airflow.providers.google.cloud.operators.kubernetes_engine.GKEStartPodOperator
    - operator: "GKEStartPodOperator"

      args:
        task_id: "gke_start_pod_task"
        project_id: "{{ var.value.gcp_project_id }}"
        location: "{{ var.value.gcp_location }}"

        # The name of the Google Kubernetes Engine cluster the pod should be spawned in
        cluster_name: "GKE_CLUSTER_NAME"

        # The namespace to run within Kubernetes
        namespace: "default"

        # The name of the pod in which the task will run. This will be used (plus a random suffix) to generate a pod id
        name: "sample-gke-pod"

        # The GCR image URL. It's recommended to redact its value and set it using Airflow variables
        image: "{{ var.json.DATASET_FOLDER_NAME.container_registry.IMAGE_REPOSITORY }}"

        # [Optional] Entrypoint command for the container
        cmds:
          - "mkdir -p /airflow/xcom/ &&"
          - "echo '[1,2,3,4]' > /airflow/xcom/return.json"

        # [Optional] Enable the usage of XCom on the operator. XCom allows you to store values used downstream
        # in your DAG. To do this, create a `return.json` file under /airflow/xcom in your pod script. To use
        # XCom variables in other operators, use the macro {{ task_instance.xcom_pull('POD_TASK_ID')[0] }}
        do_xcom_push: True

    # Deletes a GKE cluster, including the Kubernetes endpoint and all worker nodes.
    - operator: "GKEDeleteClusterOperator"

      args:
        task_id: "gke_delete_cluster_task"
        project_id: "{{ var.value.gcp_project_id }}"
        location: "{{ var.value.gcp_location }}"

        # The GKE cluster name
        name: "sample-gke-cluster"

        # Optional service account to impersonate using short-term credentials
        impersonation_chain: "{{ var.json.DATASET_FOLDER_NAME.PIPELINE_FOLDER_NAME.service_account }}"

    # Create a GKE cluster of specified dimensions. The operator will wait until the cluster is created.
    - operator: "GKECreateClusterOperator"

      args:
        task_id: "gke_create_cluster_task"
        project_id: "{{ var.value.gcp_project_id }}"
        location: "{{ var.value.gcp_location }}"

        # The cluster definition to create,
        # see https://googleapis.dev/python/container/latest/container_v1/types.html#google.cloud.container_v1.types.Cluster
        body:
          name: "sample-gke-cluster"
          initial_node_count: 1

        # Optional service account to impersonate using short-term credentials
        impersonation_chain: "{{ var.json.DATASET_FOLDER_NAME.PIPELINE_FOLDER_NAME.service_account }}"


    # Launch Cloud Dataflow jobs written in Python
    # https://airflow.apache.org/docs/apache-airflow-providers-google/stable/_api/airflow/providers/google/cloud/operators/dataflow/index.html#airflow.providers.google.cloud.operators.dataflow.DataflowCreatePythonJobOperator
    #
    # You must organize your files as follows:
    #
    #   datasets/DATASET_NAME/PIPELINE_NAME/custom/
    #       DATAFLOW_JOB_NAME/
    #           main.py          (contains the Beam Pipeline definition)
    #           setup.py         (this file is required)
    #           my_package/      (optional folder containing custom dependencies)
    #               __init__.py  (this file is required inside every package subfolder)
    #               my_file.py
    #               ...
    #           ...
    - operator: "DataflowCreatePythonJobOperator"
      description: "Task to run a Dataflow job"

      args:
        task_id: "sample_dataflow_task"

        # Path to the Python script containing the Apache Beam Pipeline definition.
        # Place the script in your pipeline's `custom` folder, preferrably namespaced
        # under a folder named after the job name (templated as `DATAFLOW_JOB_NAME`).
        py_file: "{{ var.value.airflow_dags_folder }}/DATASET_NAME/PIPELINE_NAME/custom/DATAFLOW_JOB_NAME/main.py"

        # Python version of the Beam pipeline. If None, this defaults to python3.
        py_interpreter: "python3"

        # List of Python package(s) required by your Dataflow job.
        # The three packages listed below are often needed.
        py_requirements:
          - "apache-beam"
          - "google-apitools"
          - "google-cloud-storage"

        dataflow_default_options:

          # Your Google Cloud project ID
          project: "{{ var.value.gcp_project }}"

          # [Required] Path for temporary files.
          # You can use the Composer bucket (preferred) or your own bucket.
          # When using the Cloud Composer bucket, use the templated path below to prevent collisions.
          temp_location: "{{ var.value.composer_bucket }}/data/DATASET_NAME/PIPELINE_NAME/dataflow/tmp/DATAFLOW_JOB_NAME/"

          # The GCS bucket path to store staging binary files used by Apache Beam
          # You can use the Composer bucket (preferred) or your own bucket.
          # When using the Cloud Composer bucket, use the templated path below to prevent collisions.
          staging_location: "{{ var.value.composer_bucket }}/data/DATASET_NAME/PIPELINE_NAME/dataflow/staging/"

          # [Optional] If your pipeline uses public packages from the PyPI, make
          # these packages available via a requirements.txt file. Create the file
          # in the `custom` folder, in the same subfolder as your `main.py`.
          requirements_file: "{{ var.value.airflow_dags_folder }}/DATASET_NAME/PIPELINE_NAME/custom/DATAFLOW_JOB_NAME/requirements.txt"

          # [Required] The pipeline runner to use. Must be set to "DataflowRunner" to run on
          # Google Cloud Dataflow. Keep this unchanged.
          runner: "DataflowRunner"

          # [Optional] Use the parameter below if you have custom Python dependencies for the job.
          # For instance, if you have a main.py file that contains your Apache Beam Pipeline definition
          # along with references to other packages/files you've written (i.e. non-PyPI):
          #
          #   import apache_beam as beam
          #   from my_package import my_file
          #
          #   # Define data transforms
          #   my_class = my_file.MyClass(...)
          #   my_file.my_function(...)
          #   ...
          #
          #   # Define pipeline
          #   with beam.Pipeline(options=options) as pipeline:
          #       (
          #           pipeline
          #           | "stage_1" >> beam.Create(collection)
          #           | "stage_2" >> beam.Map(...)
          #           | "stage_3" >> beam.MapTuple(...)
          #           | "stage_3" >> beam.FlatMap(...)
          #           ...
          #       )
          #   ...
          #
          # you must organize your files as follows:
          #
          #   datasets/DATASET_NAME/PIPELINE_NAME/custom/
          #       DATAFLOW_JOB_NAME/
          #           main.py
          #           setup.py              (this file is required when using custom packages)
          #           requirements.txt
          #           my_package/           (folder containing a custom package)
          #               __init__.py       (this file is required inside every package subfolder)
          #               my_file.py
          #               ...
          #           ...
          #
          # where every subfolder is a package. You must also include a setup.py in the same directory as main.py.
          # Your setup.py must contain
          #
          #   import setuptools
          #
          #   setuptools.setup(
          #       name='DATAFLOW_JOB_NAME',
          #       version='1.0.0',
          #       install_requires=[],
          #       packages=setuptools.find_packages(),
          #   )
          #
          # (For more info, see https://beam.apache.org/documentation/sdks/python-pipeline-dependencies/#multiple-file-dependencies)
          #
          # Now, use this parameter to declare the path to the setup.py file under /home/airflow/gcs/dags
          setup_file: "/home/airflow/gcs/dags/DATASET_NAME/PIPELINE_NAME/custom/DATAFLOW_JOB_NAME/setup.py"

          # [Optional] The Google Compute Engine machine type, must be n1-standard-2 or higher.
          # GCE machine types: https://cloud.google.com/compute/docs/machine-types.
          # The Dataflow service chooses the machine type based on your job if you do not set this option.
          machine_type: "n1-standard-2"

          # [Optional] The disk size, in gigabytes, to use on each remote Compute Engine worker instance.
          # Set to 0 to use the default size defined in your Cloud Platform project.
          disk_size_gb: 64

          # [Optional] The maximum number of workers to be made available to your
          # pipeline during execution. If unspecified, Dataflow determines an
          # appropriate number of workers, usually set to 12 or 18.
          max_num_workers: 18

          # [Optional] Number of workers to use when executing the Dataflow job.
          # If not set, the Dataflow service will use a reasonable default.
          # Prefer using `max_num_workers` instead of this one to control resource
          # limits and let autoscaling adjust the workers up to that number.
          num_workers: 1

  graph_paths:
    # This is where you specify the relationships (i.e. directed paths/edges)
    # among the tasks specified above. Use the bitshift operator to define the
    # relationships and the `task_id` value above to represent tasks.
    #
    # For more info, see
    # https://airflow.apache.org/docs/apache-airflow/stable/tutorial.html#setting-up-dependencies
    - "sample_bash_task >> [sample_gcs_to_bq_task, sample_gcs_to_gcs_task, sample_data_transfer_service_gcs_to_gcs]"
    - "sample_gcs_to_bq_task >> sample_dataflow_task >> [sample_bq_sql_task, gcs_delete_task]"
    - "gke_create_cluster_task >> gke_start_pod_task >> gke_delete_cluster_task"