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"""This module contains Google Cloud Storage to S3 operator."""
from __future__ import annotations
import os
from typing import TYPE_CHECKING, Sequence
from airflow.models import BaseOperator
from airflow.providers.amazon.aws.hooks.s3 import S3Hook
from airflow.providers.google.cloud.hooks.gcs import GCSHook
if TYPE_CHECKING:
from airflow.utils.context import Context
[docs]class GCSToS3Operator(BaseOperator):
"""
Synchronizes a Google Cloud Storage bucket with an S3 bucket.
.. seealso::
For more information on how to use this operator, take a look at the guide:
:ref:`howto/operator:GCSToS3Operator`
:param bucket: The Google Cloud Storage bucket to find the objects. (templated)
:param prefix: Prefix string which filters objects whose name begin with
this prefix. (templated)
:param delimiter: The delimiter by which you want to filter the objects. (templated)
For e.g to lists the CSV files from in a directory in GCS you would use
delimiter='.csv'.
:param gcp_conn_id: (Optional) The connection ID used to connect to Google Cloud.
:param dest_aws_conn_id: The destination S3 connection
:param dest_s3_key: The base S3 key to be used to store the files. (templated)
:param dest_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.
:param replace: Whether or not to verify the existence of the files in the
destination bucket.
By default is set to False
If set to True, will upload all the files replacing the existing ones in
the destination bucket.
If set to False, will upload only the files that are in the origin but not
in the destination bucket.
:param google_impersonation_chain: Optional Google service account to impersonate using
short-term credentials, or chained list of accounts required to get the access_token
of the last account in the list, which will be impersonated in the request.
If set as a string, the account must grant the originating account
the Service Account Token Creator IAM role.
If set as a sequence, the identities from the list must grant
Service Account Token Creator IAM role to the directly preceding identity, with first
account from the list granting this role to the originating account (templated).
:param s3_acl_policy: Optional The string to specify the canned ACL policy for the
object to be uploaded in S3
:param keep_directory_structure: (Optional) When set to False the path of the file
on the bucket is recreated within path passed in dest_s3_key.
"""
[docs] template_fields: Sequence[str] = (
"bucket",
"prefix",
"delimiter",
"dest_s3_key",
"google_impersonation_chain",
)
def __init__(
self,
*,
bucket: str,
prefix: str | None = None,
delimiter: str | None = None,
gcp_conn_id: str = "google_cloud_default",
dest_aws_conn_id: str = "aws_default",
dest_s3_key: str,
dest_verify: str | bool | None = None,
replace: bool = False,
google_impersonation_chain: str | Sequence[str] | None = None,
dest_s3_extra_args: dict | None = None,
s3_acl_policy: str | None = None,
keep_directory_structure: bool = True,
**kwargs,
) -> None:
super().__init__(**kwargs)
self.bucket = bucket
self.prefix = prefix
self.delimiter = delimiter
self.gcp_conn_id = gcp_conn_id
self.dest_aws_conn_id = dest_aws_conn_id
self.dest_s3_key = dest_s3_key
self.dest_verify = dest_verify
self.replace = replace
self.google_impersonation_chain = google_impersonation_chain
self.dest_s3_extra_args = dest_s3_extra_args or {}
self.s3_acl_policy = s3_acl_policy
self.keep_directory_structure = keep_directory_structure
[docs] def execute(self, context: Context) -> list[str]:
# list all files in an Google Cloud Storage bucket
hook = GCSHook(
gcp_conn_id=self.gcp_conn_id,
impersonation_chain=self.google_impersonation_chain,
)
self.log.info(
"Getting list of the files. Bucket: %s; Delimiter: %s; Prefix: %s",
self.bucket,
self.delimiter,
self.prefix,
)
files = hook.list(bucket_name=self.bucket, prefix=self.prefix, delimiter=self.delimiter)
s3_hook = S3Hook(
aws_conn_id=self.dest_aws_conn_id, verify=self.dest_verify, extra_args=self.dest_s3_extra_args
)
if not self.keep_directory_structure and self.prefix:
self.dest_s3_key = os.path.join(self.dest_s3_key, self.prefix)
if not self.replace:
# if we are not replacing -> list all files in the S3 bucket
# and only keep those files which are present in
# Google Cloud Storage and not in S3
bucket_name, prefix = S3Hook.parse_s3_url(self.dest_s3_key)
# look for the bucket and the prefix to avoid look into
# parent directories/keys
existing_files = s3_hook.list_keys(bucket_name, prefix=prefix)
# in case that no files exists, return an empty array to avoid errors
existing_files = existing_files if existing_files is not None else []
# remove the prefix for the existing files to allow the match
existing_files = [file.replace(prefix, "", 1) for file in existing_files]
files = list(set(files) - set(existing_files))
if files:
for file in files:
with hook.provide_file(object_name=file, bucket_name=self.bucket) as local_tmp_file:
dest_key = os.path.join(self.dest_s3_key, file)
self.log.info("Saving file to %s", dest_key)
s3_hook.load_file(
filename=local_tmp_file.name,
key=dest_key,
replace=self.replace,
acl_policy=self.s3_acl_policy,
)
self.log.info("All done, uploaded %d files to S3", len(files))
else:
self.log.info("In sync, no files needed to be uploaded to S3")
return files
