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"""
Example DAG using PostgresSQLToGCSOperator.
This DAG relies on the following OS environment variables
* AIRFLOW__API__GOOGLE_KEY_PATH - Path to service account key file. Note, you can skip this variable if you
run this DAG in a Composer environment.
"""
from __future__ import annotations
import logging
import os
from datetime import datetime
from airflow.decorators import task
from airflow.models import Connection
from airflow.models.dag import DAG
from airflow.providers.common.sql.operators.sql import SQLExecuteQueryOperator
from airflow.providers.google.cloud.hooks.compute import ComputeEngineHook
from airflow.providers.google.cloud.hooks.compute_ssh import ComputeEngineSSHHook
from airflow.providers.google.cloud.operators.compute import (
ComputeEngineDeleteInstanceOperator,
ComputeEngineInsertInstanceOperator,
)
from airflow.providers.google.cloud.operators.gcs import (
GCSCreateBucketOperator,
GCSDeleteBucketOperator,
)
from airflow.providers.google.cloud.transfers.postgres_to_gcs import PostgresToGCSOperator
from airflow.providers.ssh.operators.ssh import SSHOperator
from airflow.providers.standard.operators.bash import BashOperator
from airflow.settings import Session
from airflow.utils.trigger_rule import TriggerRule
[docs]DAG_ID = "postgres_to_gcs"
[docs]ENV_ID = os.environ.get("SYSTEM_TESTS_ENV_ID", "default")
[docs]PROJECT_ID = os.environ.get("SYSTEM_TESTS_GCP_PROJECT", "example-project")
[docs]CONNECTION_ID = f"pg_{DAG_ID}_{ENV_ID}".replace("-", "_")
[docs]CONNECTION_TYPE = "postgres"
[docs]BUCKET_NAME = f"bucket_{DAG_ID}_{ENV_ID}"
[docs]FILE_NAME = "result.json"
[docs]DB_USER_PASSWORD = "demo_password"
[docs]SETUP_POSTGRES_COMMAND = f"""
sudo apt update &&
sudo apt install -y docker.io &&
sudo docker run -d -p {DB_PORT}:{DB_PORT} --name {DB_NAME} \
-e PGUSER={DB_USER_NAME} \
-e POSTGRES_USER={DB_USER_NAME} \
-e POSTGRES_PASSWORD={DB_USER_PASSWORD} \
-e POSTGRES_DB={DB_NAME} \
postgres
"""
[docs]SQL_TABLE = "test_table"
[docs]SQL_CREATE = f"CREATE TABLE IF NOT EXISTS {SQL_TABLE} (col_1 INT, col_2 VARCHAR(8))"
[docs]SQL_INSERT = f"INSERT INTO {SQL_TABLE} (col_1, col_2) VALUES (1, 'one'), (2, 'two')"
[docs]SQL_SELECT = f"SELECT * FROM {SQL_TABLE}"
[docs]GCE_MACHINE_TYPE = "n1-standard-1"
[docs]GCE_INSTANCE_NAME = f"instance-{DAG_ID}-{ENV_ID}".replace("_", "-")
[docs]GCE_INSTANCE_BODY = {
"name": GCE_INSTANCE_NAME,
"machine_type": f"zones/{ZONE}/machineTypes/{GCE_MACHINE_TYPE}",
"disks": [
{
"boot": True,
"device_name": GCE_INSTANCE_NAME,
"initialize_params": {
"disk_size_gb": "10",
"disk_type": f"zones/{ZONE}/diskTypes/pd-balanced",
"source_image": "projects/debian-cloud/global/images/debian-12-bookworm-v20240611",
},
}
],
"network_interfaces": [
{
"access_configs": [{"name": "External NAT", "network_tier": "PREMIUM"}],
"stack_type": "IPV4_ONLY",
"subnetwork": f"regions/{REGION}/subnetworks/default",
}
],
}
[docs]FIREWALL_RULE_NAME = f"allow-http-{DB_PORT}-{DAG_ID}-{ENV_ID}".replace("_", "-")
[docs]CREATE_FIREWALL_RULE_COMMAND = f"""
if [ $AIRFLOW__API__GOOGLE_KEY_PATH ]; then \
gcloud auth activate-service-account --key-file=$AIRFLOW__API__GOOGLE_KEY_PATH; \
fi;
if [ -z $(gcloud compute firewall-rules list --filter=name:{FIREWALL_RULE_NAME} --format="value(name)" --project={PROJECT_ID}) ]; then \
gcloud compute firewall-rules create {FIREWALL_RULE_NAME} \
--project={PROJECT_ID} \
--direction=INGRESS \
--priority=100 \
--network={NETWORK} \
--action=ALLOW \
--rules=tcp:{DB_PORT} \
--source-ranges=0.0.0.0/0
else
echo "Firewall rule {FIREWALL_RULE_NAME} already exists."
fi
"""
[docs]DELETE_FIREWALL_RULE_COMMAND = f"""
if [ $AIRFLOW__API__GOOGLE_KEY_PATH ]; then \
gcloud auth activate-service-account --key-file=$AIRFLOW__API__GOOGLE_KEY_PATH; \
fi; \
if [ $(gcloud compute firewall-rules list --filter=name:{FIREWALL_RULE_NAME} --format="value(name)" --project={PROJECT_ID}) ]; then \
gcloud compute firewall-rules delete {FIREWALL_RULE_NAME} --project={PROJECT_ID} --quiet; \
fi;
"""
[docs]DELETE_PERSISTENT_DISK_COMMAND = f"""
if [ $AIRFLOW__API__GOOGLE_KEY_PATH ]; then \
gcloud auth activate-service-account --key-file=$AIRFLOW__API__GOOGLE_KEY_PATH; \
fi;
gcloud compute disks delete {GCE_INSTANCE_NAME} --project={PROJECT_ID} --zone={ZONE} --quiet
"""
[docs]log = logging.getLogger(__name__)
with DAG(
dag_id=DAG_ID,
schedule="@once",
start_date=datetime(2021, 1, 1),
catchup=False,
tags=["example", "postgres", "gcs"],
) as dag:
[docs] create_gce_instance = ComputeEngineInsertInstanceOperator(
task_id="create_gce_instance",
project_id=PROJECT_ID,
zone=ZONE,
body=GCE_INSTANCE_BODY,
)
create_firewall_rule = BashOperator(
task_id="create_firewall_rule",
bash_command=CREATE_FIREWALL_RULE_COMMAND,
)
setup_postgres = SSHOperator(
task_id="setup_postgres",
ssh_hook=ComputeEngineSSHHook(
user="username",
instance_name=GCE_INSTANCE_NAME,
zone=ZONE,
project_id=PROJECT_ID,
use_oslogin=False,
use_iap_tunnel=False,
cmd_timeout=180,
),
command=SETUP_POSTGRES_COMMAND,
retries=2,
)
@task
def get_public_ip() -> str:
hook = ComputeEngineHook()
address = hook.get_instance_address(resource_id=GCE_INSTANCE_NAME, zone=ZONE, project_id=PROJECT_ID)
return address
get_public_ip_task = get_public_ip()
@task
def create_connection(connection_id: str, ip_address: str) -> None:
connection = Connection(
conn_id=connection_id,
description="Example connection",
conn_type=CONNECTION_TYPE,
schema=DB_NAME,
host=ip_address,
login=DB_USER_NAME,
password=DB_USER_PASSWORD,
port=DB_PORT,
)
session = Session()
log.info("Removing connection %s if it exists", connection_id)
query = session.query(Connection).filter(Connection.conn_id == connection_id)
query.delete()
session.add(connection)
session.commit()
log.info("Connection %s created", connection_id)
create_connection_task = create_connection(connection_id=CONNECTION_ID, ip_address=get_public_ip_task)
create_sql_table = SQLExecuteQueryOperator(
task_id="create_sql_table",
conn_id=CONNECTION_ID,
sql=SQL_CREATE,
retries=4,
)
insert_sql_data = SQLExecuteQueryOperator(
task_id="insert_sql_data",
conn_id=CONNECTION_ID,
sql=SQL_INSERT,
)
create_gcs_bucket = GCSCreateBucketOperator(
task_id="create_gcs_bucket",
bucket_name=BUCKET_NAME,
)
# [START howto_operator_postgres_to_gcs]
postgres_to_gcs = PostgresToGCSOperator(
task_id="postgres_to_gcs",
postgres_conn_id=CONNECTION_ID,
sql=SQL_SELECT,
bucket=BUCKET_NAME,
filename=FILE_NAME,
export_format="csv",
)
# [END howto_operator_postgres_to_gcs]
delete_gcs_bucket = GCSDeleteBucketOperator(
task_id="delete_gcs_bucket",
bucket_name=BUCKET_NAME,
trigger_rule=TriggerRule.ALL_DONE,
)
delete_firewall_rule = BashOperator(
task_id="delete_firewall_rule",
bash_command=DELETE_FIREWALL_RULE_COMMAND,
trigger_rule=TriggerRule.ALL_DONE,
)
delete_gce_instance = ComputeEngineDeleteInstanceOperator(
task_id="delete_gce_instance",
resource_id=GCE_INSTANCE_NAME,
zone=ZONE,
project_id=PROJECT_ID,
trigger_rule=TriggerRule.ALL_DONE,
)
delete_persistent_disk = BashOperator(
task_id="delete_persistent_disk",
bash_command=DELETE_PERSISTENT_DISK_COMMAND,
trigger_rule=TriggerRule.ALL_DONE,
)
@task(task_id="delete_connection")
def delete_connection(connection_id: str) -> None:
session = Session()
log.info("Removing connection %s", connection_id)
query = session.query(Connection).filter(Connection.conn_id == connection_id)
query.delete()
session.commit()
delete_connection_task = delete_connection(connection_id=CONNECTION_ID)
# TEST SETUP
create_gce_instance >> get_public_ip_task >> create_connection_task
[create_gce_instance, create_firewall_rule] >> setup_postgres
[setup_postgres, create_connection_task, create_firewall_rule] >> create_sql_table >> insert_sql_data
(
[create_gcs_bucket, insert_sql_data]
# TEST BODY
>> postgres_to_gcs
)
# TEST TEARDOWN
postgres_to_gcs >> [delete_gcs_bucket, delete_firewall_rule, delete_gce_instance, delete_connection_task]
delete_gce_instance >> delete_persistent_disk
from tests_common.test_utils.watcher import watcher
# This test needs watcher in order to properly mark success/failure
# when "tearDown" task with trigger rule is part of the DAG
list(dag.tasks) >> watcher()
from tests_common.test_utils.system_tests import get_test_run # noqa: E402
# Needed to run the example DAG with pytest (see: tests/system/README.md#run_via_pytest)
[docs]test_run = get_test_run(dag)