Source code for airflow.providers.amazon.aws.transfers.s3_to_redshift
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from typing import List, Optional, Union
from airflow.models import BaseOperator
from airflow.providers.amazon.aws.hooks.s3 import S3Hook
from airflow.providers.amazon.aws.utils.redshift import build_credentials_block
from airflow.providers.postgres.hooks.postgres import PostgresHook
[docs]class S3ToRedshiftOperator(BaseOperator):
"""
Executes an COPY command to load files from s3 to Redshift
.. seealso::
For more information on how to use this operator, take a look at the guide:
:ref:`howto/operator:S3ToRedshiftOperator`
:param schema: reference to a specific schema in redshift database
:type schema: str
:param table: reference to a specific table in redshift database
:type table: str
:param s3_bucket: reference to a specific S3 bucket
:type s3_bucket: str
:param s3_key: reference to a specific S3 key
:type s3_key: str
:param redshift_conn_id: reference to a specific redshift database
:type redshift_conn_id: str
:param aws_conn_id: reference to a specific S3 connection
If the AWS connection contains 'aws_iam_role' in ``extras``
the operator will use AWS STS credentials with a token
https://docs.aws.amazon.com/redshift/latest/dg/copy-parameters-authorization.html#copy-credentials
:type aws_conn_id: str
:param verify: Whether or not to verify SSL certificates for S3 connection.
By default SSL certificates are verified.
You can provide the following values:
- ``False``: do not validate SSL certificates. SSL will still be used
(unless use_ssl is False), but SSL certificates will not be
verified.
- ``path/to/cert/bundle.pem``: A filename of the CA cert bundle to uses.
You can specify this argument if you want to use a different
CA cert bundle than the one used by botocore.
:type verify: bool or str
:param column_list: list of column names to load
:type column_list: List[str]
:param copy_options: reference to a list of COPY options
:type copy_options: list
:param truncate_table: whether or not to truncate the destination table before the copy
:type truncate_table: bool
"""
[docs] template_fields = ('s3_bucket', 's3_key', 'schema', 'table', 'column_list', 'copy_options')
def __init__(
self,
*,
schema: str,
table: str,
s3_bucket: str,
s3_key: str,
redshift_conn_id: str = 'redshift_default',
aws_conn_id: str = 'aws_default',
verify: Optional[Union[bool, str]] = None,
column_list: Optional[List[str]] = None,
copy_options: Optional[List] = None,
autocommit: bool = False,
truncate_table: bool = False,
**kwargs,
) -> None:
super().__init__(**kwargs)
self.schema = schema
self.table = table
self.s3_bucket = s3_bucket
self.s3_key = s3_key
self.redshift_conn_id = redshift_conn_id
self.aws_conn_id = aws_conn_id
self.verify = verify
self.column_list = column_list
self.copy_options = copy_options or []
self.autocommit = autocommit
self.truncate_table = truncate_table
def _build_copy_query(self, credentials_block: str, copy_options: str) -> str:
column_names = "(" + ", ".join(self.column_list) + ")" if self.column_list else ''
return f"""
COPY {self.schema}.{self.table} {column_names}
FROM 's3://{self.s3_bucket}/{self.s3_key}'
with credentials
'{credentials_block}'
{copy_options};
"""
[docs] def execute(self, context) -> None:
postgres_hook = PostgresHook(postgres_conn_id=self.redshift_conn_id)
s3_hook = S3Hook(aws_conn_id=self.aws_conn_id, verify=self.verify)
credentials = s3_hook.get_credentials()
credentials_block = build_credentials_block(credentials)
copy_options = '\n\t\t\t'.join(self.copy_options)
copy_statement = self._build_copy_query(credentials_block, copy_options)
if self.truncate_table:
delete_statement = f'DELETE FROM {self.schema}.{self.table};'
sql = f"""
BEGIN;
{delete_statement}
{copy_statement}
COMMIT
"""
else:
sql = copy_statement
self.log.info('Executing COPY command...')
postgres_hook.run(sql, self.autocommit)
self.log.info("COPY command complete...")