#
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# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you 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
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# KIND, either express or implied. See the License for the
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"""
Note: DMS requires you to configure specific IAM roles/permissions. For more information, see
https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Security.html#CHAP_Security.APIRole
"""
import json
import os
from datetime import datetime
import boto3
from sqlalchemy import Column, MetaData, String, Table, create_engine
from airflow import DAG
from airflow.decorators import task
from airflow.models.baseoperator import chain
from airflow.operators.python import get_current_context
from airflow.providers.amazon.aws.operators.dms import (
DmsCreateTaskOperator,
DmsDeleteTaskOperator,
DmsDescribeTasksOperator,
DmsStartTaskOperator,
DmsStopTaskOperator,
)
from airflow.providers.amazon.aws.operators.rds import (
RdsCreateDbInstanceOperator,
RdsDeleteDbInstanceOperator,
)
from airflow.providers.amazon.aws.sensors.dms import DmsTaskBaseSensor, DmsTaskCompletedSensor
[docs]S3_BUCKET = os.getenv('S3_BUCKET', 's3_bucket_name')
[docs]ROLE_ARN = os.getenv('ROLE_ARN', 'arn:aws:iam::1234567890:role/s3_target_endpoint_role')
# The project name will be used as a prefix for various entity names.
# Use either PascalCase or camelCase. While some names require kebab-case
# and others require snake_case, they all accept mixedCase strings.
[docs]PROJECT_NAME = 'DmsDemo'
# Config values for setting up the "Source" database.
[docs]RDS_PROTOCOL = 'postgresql'
[docs]RDS_USERNAME = 'username'
# NEVER store your production password in plaintext in a DAG like this.
# Use Airflow Secrets or a secret manager for this in production.
[docs]RDS_PASSWORD = 'rds_password'
# Config values for RDS.
[docs]RDS_INSTANCE_NAME = f'{PROJECT_NAME}-instance'
[docs]RDS_DB_NAME = f'{PROJECT_NAME}_source_database'
# Config values for DMS.
[docs]DMS_REPLICATION_INSTANCE_NAME = f'{PROJECT_NAME}-replication-instance'
[docs]DMS_REPLICATION_TASK_ID = f'{PROJECT_NAME}-replication-task'
[docs]SOURCE_ENDPOINT_IDENTIFIER = f'{PROJECT_NAME}-source-endpoint'
[docs]TARGET_ENDPOINT_IDENTIFIER = f'{PROJECT_NAME}-target-endpoint'
# Sample data.
[docs]TABLE_NAME = f'{PROJECT_NAME}-table'
[docs]SAMPLE_DATA = [
('Airflow', '2015'),
('OpenOffice', '2012'),
('Subversion', '2000'),
('NiFi', '2006'),
]
[docs]TABLE_DEFINITION = {
'TableCount': '1',
'Tables': [
{
'TableName': TABLE_NAME,
'TableColumns': [
{
'ColumnName': TABLE_HEADERS[0],
'ColumnType': 'STRING',
'ColumnNullable': 'false',
'ColumnIsPk': 'true',
},
{"ColumnName": TABLE_HEADERS[1], "ColumnType": 'STRING', "ColumnLength": "4"},
],
'TableColumnsTotal': '2',
}
],
}
[docs]TABLE_MAPPINGS = {
'rules': [
{
'rule-type': 'selection',
'rule-id': '1',
'rule-name': '1',
'object-locator': {
'schema-name': 'public',
'table-name': TABLE_NAME,
},
'rule-action': 'include',
}
]
}
def _get_rds_instance_endpoint():
print('Retrieving RDS instance endpoint.')
rds_client = boto3.client('rds')
response = rds_client.describe_db_instances(DBInstanceIdentifier=RDS_INSTANCE_NAME)
rds_instance_endpoint = response['DBInstances'][0]['Endpoint']
return rds_instance_endpoint
@task
[docs]def create_sample_table():
print('Creating sample table.')
rds_endpoint = _get_rds_instance_endpoint()
hostname = rds_endpoint['Address']
port = rds_endpoint['Port']
rds_url = f'{RDS_PROTOCOL}://{RDS_USERNAME}:{RDS_PASSWORD}@{hostname}:{port}/{RDS_DB_NAME}'
engine = create_engine(rds_url)
table = Table(
TABLE_NAME,
MetaData(engine),
Column(TABLE_HEADERS[0], String, primary_key=True),
Column(TABLE_HEADERS[1], String),
)
with engine.connect() as connection:
# Create the Table.
table.create()
load_data = table.insert().values(SAMPLE_DATA)
connection.execute(load_data)
# Read the data back to verify everything is working.
connection.execute(table.select())
@task
[docs]def create_dms_assets():
print('Creating DMS assets.')
ti = get_current_context()['ti']
dms_client = boto3.client('dms')
rds_instance_endpoint = _get_rds_instance_endpoint()
print('Creating replication instance.')
instance_arn = dms_client.create_replication_instance(
ReplicationInstanceIdentifier=DMS_REPLICATION_INSTANCE_NAME,
ReplicationInstanceClass='dms.t3.micro',
)['ReplicationInstance']['ReplicationInstanceArn']
ti.xcom_push(key='replication_instance_arn', value=instance_arn)
print('Creating DMS source endpoint.')
source_endpoint_arn = dms_client.create_endpoint(
EndpointIdentifier=SOURCE_ENDPOINT_IDENTIFIER,
EndpointType='source',
EngineName=RDS_ENGINE,
Username=RDS_USERNAME,
Password=RDS_PASSWORD,
ServerName=rds_instance_endpoint['Address'],
Port=rds_instance_endpoint['Port'],
DatabaseName=RDS_DB_NAME,
)['Endpoint']['EndpointArn']
print('Creating DMS target endpoint.')
target_endpoint_arn = dms_client.create_endpoint(
EndpointIdentifier=TARGET_ENDPOINT_IDENTIFIER,
EndpointType='target',
EngineName='s3',
S3Settings={
'BucketName': S3_BUCKET,
'BucketFolder': PROJECT_NAME,
'ServiceAccessRoleArn': ROLE_ARN,
'ExternalTableDefinition': json.dumps(TABLE_DEFINITION),
},
)['Endpoint']['EndpointArn']
ti.xcom_push(key='source_endpoint_arn', value=source_endpoint_arn)
ti.xcom_push(key='target_endpoint_arn', value=target_endpoint_arn)
print("Awaiting replication instance provisioning.")
dms_client.get_waiter('replication_instance_available').wait(
Filters=[{'Name': 'replication-instance-arn', 'Values': [instance_arn]}]
)
@task(trigger_rule='all_done')
[docs]def delete_dms_assets():
ti = get_current_context()['ti']
dms_client = boto3.client('dms')
replication_instance_arn = ti.xcom_pull(key='replication_instance_arn')
source_arn = ti.xcom_pull(key='source_endpoint_arn')
target_arn = ti.xcom_pull(key='target_endpoint_arn')
print('Deleting DMS assets.')
dms_client.delete_replication_instance(ReplicationInstanceArn=replication_instance_arn)
dms_client.delete_endpoint(EndpointArn=source_arn)
dms_client.delete_endpoint(EndpointArn=target_arn)
print('Awaiting DMS assets tear-down.')
dms_client.get_waiter('replication_instance_deleted').wait(
Filters=[{'Name': 'replication-instance-id', 'Values': [DMS_REPLICATION_INSTANCE_NAME]}]
)
dms_client.get_waiter('endpoint_deleted').wait(
Filters=[
{
'Name': 'endpoint-id',
'Values': [SOURCE_ENDPOINT_IDENTIFIER, TARGET_ENDPOINT_IDENTIFIER],
}
]
)
with DAG(
dag_id='example_dms',
schedule_interval=None,
start_date=datetime(2021, 1, 1),
tags=['example'],
catchup=False,
) as dag:
[docs] create_db_instance = RdsCreateDbInstanceOperator(
task_id="create_db_instance",
db_instance_identifier=RDS_INSTANCE_NAME,
db_instance_class='db.t3.micro',
engine=RDS_ENGINE,
rds_kwargs={
"DBName": RDS_DB_NAME,
"AllocatedStorage": 20,
"MasterUsername": RDS_USERNAME,
"MasterUserPassword": RDS_PASSWORD,
},
)
# [START howto_operator_dms_create_task]
create_task = DmsCreateTaskOperator(
task_id='create_task',
replication_task_id=DMS_REPLICATION_TASK_ID,
source_endpoint_arn='{{ ti.xcom_pull(key="source_endpoint_arn") }}',
target_endpoint_arn='{{ ti.xcom_pull(key="target_endpoint_arn") }}',
replication_instance_arn='{{ ti.xcom_pull(key="replication_instance_arn") }}',
table_mappings=TABLE_MAPPINGS,
)
# [END howto_operator_dms_create_task]
# [START howto_operator_dms_start_task]
start_task = DmsStartTaskOperator(
task_id='start_task',
replication_task_arn=create_task.output,
)
# [END howto_operator_dms_start_task]
# [START howto_operator_dms_describe_tasks]
describe_tasks = DmsDescribeTasksOperator(
task_id='describe_tasks',
describe_tasks_kwargs={
'Filters': [
{
'Name': 'replication-instance-arn',
'Values': ['{{ ti.xcom_pull(key="replication_instance_arn") }}'],
}
]
},
do_xcom_push=False,
)
# [END howto_operator_dms_describe_tasks]
await_task_start = DmsTaskBaseSensor(
task_id='await_task_start',
replication_task_arn=create_task.output,
target_statuses=['running'],
termination_statuses=['stopped', 'deleting', 'failed'],
)
# [START howto_operator_dms_stop_task]
stop_task = DmsStopTaskOperator(
task_id='stop_task',
replication_task_arn=create_task.output,
)
# [END howto_operator_dms_stop_task]
# TaskCompletedSensor actually waits until task reaches the "Stopped" state, so it will work here.
# [START howto_sensor_dms_task_completed]
await_task_stop = DmsTaskCompletedSensor(
task_id='await_task_stop',
replication_task_arn=create_task.output,
)
# [END howto_sensor_dms_task_completed]
# [START howto_operator_dms_delete_task]
delete_task = DmsDeleteTaskOperator(
task_id='delete_task',
replication_task_arn=create_task.output,
trigger_rule='all_done',
)
# [END howto_operator_dms_delete_task]
delete_db_instance = RdsDeleteDbInstanceOperator(
task_id='delete_db_instance',
db_instance_identifier=RDS_INSTANCE_NAME,
rds_kwargs={
"SkipFinalSnapshot": True,
},
trigger_rule='all_done',
)
chain(
create_db_instance,
create_sample_table(),
create_dms_assets(),
create_task,
start_task,
describe_tasks,
await_task_start,
stop_task,
await_task_stop,
delete_task,
delete_dms_assets(),
delete_db_instance,
)
