starlake-airflow 0.1.1

Starlake Python Distribution For Airflow

starlake-airflow

starlake-airflow is the Starlake Python Distribution for Airflow.

It is recommended to use it in combinaison with starlake dag generation, but can be used directly as is in your DAGs.

Prerequisites

Before installing starlake-airflow, ensure the following minimum versions are installed on your system:

• starlake: 1.0.0 or higher
• python: 3.8 or higher
• Apache Airflow: 2.4.0 or higher (2.6.0 or higher is recommanded with cloud-run)

Installation

pip install starlake-airflow --upgrade

StarlakeAirflowJob

ai.starlake.airflow.StarlakeAirflowJob is an abstract factory class that extends the generic factory interface ai.starlake.job.IStarlakeJob and is responsible for generating the Airflow tasks that will run the import, load and transform starlake commands.

sl_import

It generates the Airflow task that will run the starlake import command.

def sl_import(
    self, 
    task_id: str, 
    domain: str, 
    **kwargs) -> BaseOperator:
    #...

name	type	description
task_id	str	the optional task id ({domain}_import by default)
domain	str	the required domain to import

sl_load

It generates the Airflow task that will run the starlake load command.

def sl_load(
    self, 
    task_id: str, 
    domain: str, 
    table: str, 
    spark_config: StarlakeSparkConfig=None,
    **kwargs) -> BaseOperator:
    #...

name	type	description
task_id	str	the optional task id ({domain}_{table}_load by default)
domain	str	the required domain of the table to load
table	str	the required table to load
spark_config	StarlakeSparkConfig	the optional ai.starlake.job.StarlakeSparkConfig

sl_transform

It generates the Airflow task that will run the starlake transform command.

def sl_transform(
    self, 
    task_id: str, 
    transform_name: str, 
    transform_options: str=None, 
    spark_config: StarlakeSparkConfig=None, **kwargs) -> BaseOperator:
    #...

name	type	description
task_id	str	the optional task id ({transform_name} by default)
transform_name	str	the transform to run
transform_options	str	the optional transform options
spark_config	StarlakeSparkConfig	the optional ai.starlake.job.StarlakeSparkConfig

sl_job

Ultimately, all of these methods will call the sl_job method that needs to be implemented in all concrete factory classes.

def sl_job(
    self, 
    task_id: str, 
    arguments: list, 
    spark_config: StarlakeSparkConfig=None, 
    **kwargs) -> BaseOperator:
    #...

name	type	description
task_id	str	the required task id
arguments	list	The required arguments of the starlake command to run
spark_config	StarlakeSparkConfig	the optional ai.starlake.job.StarlakeSparkConfig

Init

To initialize this class, you may specify the optional pre load strategy and options to use.

    def __init__(self, pre_load_strategy: Union[StarlakePreLoadStrategy, str, None], options: dict=None, **kwargs) -> None:
        """Overrides IStarlakeJob.__init__()
        Args:
            pre_load_strategy (Union[StarlakePreLoadStrategy, str, None]): The pre-load strategy to use.
            options (dict): The options to use.
        """
        super().__init__(pre_load_strategy, options, **kwargs)
        #...

StarlakePreLoadStrategy

ai.starlake.job.StarlakePreLoadStrategy is an enum that defines the different pre load strategies that can be used to conditionaly load a domain.

The pre-load strategy is implemented by sl_pre_load method that will generate the Airflow group of tasks corresponding to the choosen strategy.

def sl_pre_load(
    self, 
    domain: str, 
    pre_load_strategy: Union[StarlakePreLoadStrategy, str, None]=None,
    **kwargs) -> BaseOperator:
    #...

name	type	description
domain	str	the domain to load
pre_load_strategy	str	the optional pre load strategy (self.pre_load_strategy by default)

StarlakePreLoadStrategy.NONE

The load of the domain will not be conditionned and no pre-load tasks will be executed.

StarlakePreLoadStrategy.IMPORTED

This strategy implies that at least one file is present in the landing area (SL_ROOT/importing/{domain} by default, if option incoming_path has not been specified). If there is one or more files to load, the method sl_import will be called to import the domain before loading it, otherwise the loading of the domain will be skipped.

StarlakePreLoadStrategy.PENDING

This strategy implies that at least one file is present in the pending datasets area of the domain (SL_ROOT/datasets/pending/{domain} by default if option pending_path has not been specified), otherwise the loading of the domain will be skipped.

StarlakePreLoadStrategy.ACK

This strategy implies that an ack file is present at the specified path (option global_ack_file_path), otherwise the loading of the domain will be skipped.

Options

The following options can be specified in all concrete factory classes:

name	type	description
default_pool	str	pool of slots to use (default_pool by default)
sl_env_var	str	optional starlake environment variables passed as an encoded json string
pre_load_strategy	str	one of none (default), imported, pending or ack
incoming_path	str	path to the landing area for the domain to load ({SL_ROOT}/incoming by default)
pending_path	str	path to the pending datastets for the domain to load ({SL_DATASETS}/pending by default)
global_ack_file_path	str	path to the ack file ({SL_DATASETS}/pending/{domain}/{{{{ds}}}}.ack by default)
ack_wait_timeout	int	timeout in seconds to wait for the ack file(1 hour by default)

Data-aware scheduling

The ai.starlake.airflow.StarlakeAirflowJob class is also responsible for recording the outlets related to the execution of each starlake command, usefull for scheduling DAGs using data-aware scheduling.

All the outlets that have been recorded are available in the outlets property of the instance of the concrete class.

def __init__(
    self, 
    pre_load_strategy: Union[StarlakePreLoadStrategy, str, None], 
    options: dict=None, 
    **kwargs) -> None:
    #...
    self.outlets: List[Dataset] = kwargs.get('outlets', [])

def sl_import(self, task_id: str, domain: str, **kwargs) -> BaseOperator:
    #...
    dataset = Dataset(keep_ascii_only(domain).lower())
    self.outlets += kwargs.get('outlets', []) + [dataset]
    #...

def sl_load(
    self, 
    task_id: str, 
    domain: str, 
    table: str, 
    spark_config: StarlakeSparkConfig=None,
    **kwargs) -> BaseOperator:
    #...
    dataset = Dataset(keep_ascii_only(f'{domain}.{table}').lower())
    self.outlets += kwargs.get('outlets', []) + [dataset]
    #...

def sl_transform(
    self, 
    task_id: str, 
    transform_name: str, 
    transform_options: str=None, 
    spark_config: StarlakeSparkConfig=None, 
    **kwargs) -> BaseOperator:
    #...
    dataset = Dataset(keep_ascii_only(transform_name).lower())
    self.outlets += kwargs.get('outlets', []) + [dataset]
    #...

In conjonction with the starlake dag generation, the outlets property can be used to schedule effortless DAGs that will run the transform commands.

On premise

StarlakeAirflowBashJob

This class is a concrete implementation of StarlakeAirflowJob that generates tasks using airflow.operators.bash.BashOperator. Usefull for on premise execution.

An additional SL_STARLAKE_PATH option is required to specify the path to the starlake executable.

StarlakeAirflowBashJob Example

The following example shows how to use StarlakeAirflowBashJob to generate dynamically DAGs that load domains using starlake and record corresponding outlets.

description="""example to load domain(s) using airflow starlake bash job"""

options = {
    # General options
    'sl_env_var':'{"SL_ROOT": "/starlake/samples/starbake"}', 
    'pre_load_strategy':'imported', 
    # Bash options
    'SL_STARLAKE_PATH':'/starlake/starlake.sh', 
}

from ai.starlake.airflow.bash import StarlakeAirflowBashJob

sl_job = StarlakeAirflowBashJob(options=options)

schedules= [{
    'schedule': 'None',
    'cron': None,
    'domains': [{
        'name':'starbake',
        'final_name':'starbake',
        'tables': [
            {
                'name': 'Customers',
                'final_name': 'Customers'
            },
            {
                'name': 'Ingredients',
                'final_name': 'Ingredients'
            },
            {
                'name': 'Orders',
                'final_name': 'Orders'
            },
            {
                'name': 'Products',
                'final_name': 'Products'
            }
        ]
    }]
}]

def generate_dag_name(schedule):
    dag_name = os.path.basename(__file__).replace(".py", "").replace(".pyc", "").lower()
    return (f"{dag_name}-{schedule['schedule']}" if len(schedules) > 1 else dag_name)

from ai.starlake.common import keep_ascii_only, sanitize_id
from ai.starlake.airflow import DEFAULT_DAG_ARGS

import os

from airflow import DAG

from airflow.datasets import Dataset

from airflow.utils.task_group import TaskGroup

# [START instantiate_dag]
for schedule in schedules:
    for domain in schedule["domains"]:
        tags.append(domain["name"])
    with DAG(dag_id=generate_dag_name(schedule),
             schedule_interval=schedule['cron'],
             default_args=DEFAULT_DAG_ARGS,
             catchup=False,
             tags=set([tag.upper() for tag in tags]),
             description=description) as dag:
        start = sl_job.dummy_op(task_id="start")

        post_tasks = sl_job.post_tasks()

        pre_load_tasks = sl_job.sl_pre_load(domain=domain["name"])

        def generate_task_group_for_domain(domain):
            with TaskGroup(group_id=sanitize_id(f'{domain["name"]}_load_tasks')) as domain_load_tasks:
                for table in domain["tables"]:
                    load_task_id = sanitize_id(f'{domain["name"]}_{table["name"]}_load')
                    sl_job.sl_load(
                        task_id=load_task_id, 
                        domain=domain["name"], 
                        table=table["name"]
                    )
            return domain_load_tasks

        all_load_tasks = [generate_task_group_for_domain(domain) for domain in schedule["domains"]]

        if pre_load_tasks:
            start >> pre_load_tasks >> all_load_tasks
        else:
            start >> all_load_tasks

        all_done = sl_job.dummy_op(task_id="all_done", outlets=[Dataset(keep_ascii_only(dag.dag_id))]+sl_job.outlets)

        if post_tasks:
            all_load_tasks >> all_done >> post_tasks
        else:
            all_load_tasks >> all_done

Google Cloud Platform

StarlakeAirflowDataprocJob

This class is a concrete implementation of StarlakeAirflowJob that overrides the sl_job method that will run the starlake command by submitting Dataproc job to the configured Dataproc cluster.

It delegates to an instance of the ai.starlake.airflow.gcp.StarlakeDataprocCluster class the responsibility to :

• create the Dataproc cluster by instantiating airflow.providers.google.cloud.operators.dataproc.DataprocCreateClusterOperator
• submit Dataproc job to the latter by instantiating airflow.providers.google.cloud.operators.dataproc.DataprocSubmitJobOperator
• delete the Dataproc cluster by instantiating airflow.providers.google.cloud.operators.dataproc.DataprocDeleteClusterOperator

This instance is available in the cluster property of the StarlakeAirflowDataprocJob class and can be configured using the ai.starlake.airflow.gcp.StarlakeDataprocClusterConfig class.

The creation of the Dataproc cluster can be performed by calling the create_cluster method of the cluster property or by calling the pre_tasks method of the StarlakeAirflowDataprocJob (the call to the pre_load method will, behind the scene, call the pre_tasks method and add the optional resulting task to the group of Airflow tasks).

The deletion of the Dataproc cluster can be performed by calling the delete_cluster method of the cluster property or by calling the post_tasks method of the StarlakeAirflowDataprocJob.

Dataproc cluster configuration

Additional options may be specified to configure the Dataproc cluster.

name	type	description
cluster_id	str	the optional unique id of the cluster that will participate in the definition of the Dataproc cluster name (if not specified)
dataproc_name	str	the optional dataproc name of the cluster that will participate in the definition of the Dataproc cluster name (if not specified)
dataproc_project_id	str	the optional dataproc project id (the project id on which the composer has been instantiated by default)
dataproc_region	str	the optional region (europe-west1 by default)
dataproc_subnet	str	the optional subnet (the default subnet if not specified)
dataproc_service_account	str	the optional service account (service-{self.project_id}@dataproc-accounts.iam.gserviceaccount.com by default)
dataproc_image_version	str	the image version of the dataproc cluster (2.2-debian1 by default)
dataproc_master_machine_type	str	the optional master machine type (n1-standard-4 by default)
dataproc_master_disk_type	str	the optional master disk type (pd-standard by default)
dataproc_master_disk_size	int	the optional master disk size (1024 by default)
dataproc_worker_machine_type	str	the optional worker machine type (n1-standard-4 by default)
dataproc_worker_disk_type	str	the optional worker disk size (pd-standard by default)
dataproc_worker_disk_size	int	the optional worker disk size (1024 by default)
dataproc_num_workers	int	the optional number of workers (4 by default)

All of these options will be used by default if no StarlakeDataprocClusterConfig was defined when instantiating StarlakeDataprocCluster or if the latter was not defined when instantiating StarlakeAirflowDataprocJob.

Dataproc Job configuration

Additional options may be specified to configure the Dataproc job.

name	type	description
spark_jar_list	str	the required list of spark jars to be used (using , as separator)
spark_bucket	str	the required bucket to use for spark and biqquery temporary storage
spark_job_main_class	str	the optional main class of the spark job (ai.starlake.job.Main by default)
spark_executor_memory	str	the optional amount of memory to use per executor process (11g by default)
spark_executor_cores	int	the optional number of cores to use on each executor (4 by default)
spark_executor_instances	int	the optional number of executor instances (1 by default)

spark_executor_memory, spark_executor_cores and spark_executor_instances options will be used by default if no StarlakeSparkConfig was passed to the sl_load and sl_transform methods.

StarlakeAirflowDataprocJob Example

The following example shows how to use StarlakeAirflowDataprocJob to generate dynamically DAGs that load domains using starlake and record corresponding outlets.

description="""example to load domain(s) using airflow starlake dataproc job"""

options = {
    # General options
    'sl_env_var':'{"SL_ROOT": "gcs://starlake/samples/starbake"}', 
    'pre_load_strategy':'pending', 
    # Dataproc cluster configuration
    'dataproc_project_id':'starbake',
    # Dataproc job configuration 
    'spark_bucket':'my-bucket', 
    'spark_jar_list':'gcs://artifacts/starlake.jar', 
}

from ai.starlake.airflow.gcp import StarlakeAirflowDataprocJob

sl_job = StarlakeAirflowDataprocJob(options=options)

# all the code following the instantiation of the starlake job is exactly the same as that defined for StarlakeAirflowBashJob
#...

StarlakeAirflowCloudRunJob

This class is a concrete implementation of StarlakeAirflowJob that overrides the sl_job method that will run the starlake command by executing Cloud Run job.

Cloud Run job configuration

Additional options may be specified to configure the Cloud Run job.

name	type	description
cloud_run_project_id	str	the optional cloud run project id (the project id on which the composer has been instantiated by default)
cloud_run_job_name	str	the required name of the cloud run job
cloud_run_region	str	the optional region (europe-west1 by default)
cloud_run_async	bool	the optional flag to run the cloud run job asynchronously (True by default)
retry_on_failure	bool	the optional flag to retry the cloud run job on failure (False by default)
retry_delay_in_seconds	int	the optional delay in seconds to wait before retrying the cloud run job (10 by default)

If the execution has been parameterized to be asynchronous, an airflow.sensors.bash.BashSensor will be instantiated to wait for the completion of the Cloud Run job execution.

StarlakeAirflowCloudRunJob Examples

The following examples shows how to use StarlakeAirflowCloudRunJob to generate dynamically DAGs that load domains using starlake and record corresponding outlets.

Synchronous execution

description="""example to load domain(s) using airflow starlake cloud run job synchronously"""

options = {
    # General options
    'sl_env_var':'{"SL_ROOT": "gs://my-bucket/starbake"}', 
    'pre_load_strategy':'ack', 
    'global_ack_file_path':'gs://my-bucket/starbake/pending/HighValueCustomers/2024-22-01.ack', 
    # Cloud run options
    'cloud_run_job_name':'starlake', 
    'cloud_run_project_id':'starbake',
    'cloud_run_async':'False'
}

from ai.starlake.airflow.gcp import StarlakeAirflowCloudRunJob

sl_job = StarlakeAirflowCloudRunJob(options=options)
# all the code following the instantiation of the starlake job is exactly the same as that defined for StarlakeAirflowBashJob
#...

Asynchronous execution

description="""example to load domain(s) using airflow starlake cloud run job asynchronously"""

options = {
    # General options
    'sl_env_var':'{"SL_ROOT": "gs://my-bucket/starbake"}', 
    'pre_load_strategy':'pending', 
    # Cloud run options
    'cloud_run_job_name':'starlake', 
    'cloud_run_project_id':'starbake',
#    'cloud_run_async':'True'
    'retry_on_failure':'True', 
}

# all the code following the options is exactly the same as that defined above
#...

Amazon Web Services

Azure