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from __future__ import annotations
from datetime import datetime
from tempfile import NamedTemporaryFile
from typing import TYPE_CHECKING, Any, Sequence
from airflow.configuration import conf
from airflow.exceptions import AirflowException
from airflow.providers.amazon.aws.hooks.s3 import S3Hook
from airflow.providers.google.cloud.hooks.cloud_storage_transfer_service import (
ACCESS_KEY_ID,
AWS_ACCESS_KEY,
AWS_S3_DATA_SOURCE,
AWS_SECRET_ACCESS_KEY,
BUCKET_NAME,
GCS_DATA_SINK,
INCLUDE_PREFIXES,
OBJECT_CONDITIONS,
OVERWRITE_OBJECTS_ALREADY_EXISTING_IN_SINK,
PATH,
PROJECT_ID,
SCHEDULE,
SCHEDULE_END_DATE,
SCHEDULE_START_DATE,
STATUS,
TRANSFER_OPTIONS,
TRANSFER_SPEC,
CloudDataTransferServiceHook,
GcpTransferJobsStatus,
)
from airflow.providers.google.cloud.hooks.gcs import GCSHook, _parse_gcs_url, gcs_object_is_directory
from airflow.providers.google.cloud.triggers.cloud_storage_transfer_service import (
CloudStorageTransferServiceCreateJobsTrigger,
)
try:
from airflow.providers.amazon.aws.operators.s3 import S3ListOperator
except ImportError:
from airflow.providers.amazon.aws.operators.s3_list import S3ListOperator # type: ignore[no-redef]
if TYPE_CHECKING:
from airflow.utils.context import Context
[docs]class S3ToGCSOperator(S3ListOperator):
"""
Synchronizes an S3 key, possibly a prefix, with a Google Cloud Storage destination path.
.. seealso::
For more information on how to use this operator, take a look at the guide:
:ref:`howto/operator:S3ToGCSOperator`
:param bucket: The S3 bucket where to find the objects. (templated)
:param prefix: Prefix string which filters objects whose name begin with
such prefix. (templated)
:param apply_gcs_prefix: (Optional) Whether to replace source objects' path by given GCS destination path.
If apply_gcs_prefix is False (default), then objects from S3 will be copied to GCS bucket into a given
GSC path and the source path will be place inside. For example,
<s3_bucket><s3_prefix><content> => <gcs_prefix><s3_prefix><content>
If apply_gcs_prefix is True, then objects from S3 will be copied to GCS bucket into a given
GCS path and the source path will be omitted. For example:
<s3_bucket><s3_prefix><content> => <gcs_prefix><content>
:param delimiter: the delimiter marks key hierarchy. (templated)
:param aws_conn_id: The source S3 connection
: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.
:param gcp_conn_id: (Optional) The connection ID used to connect to Google Cloud.
:param dest_gcs: The destination Google Cloud Storage bucket and prefix
where you want to store the files. (templated)
:param replace: Whether you want to replace existing destination files
or not.
:param gzip: Option to compress file for upload. Parameter ignored in deferrable mode.
: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 deferrable: Run operator in the deferrable mode
:param poll_interval: time in seconds between polling for job completion.
The value is considered only when running in deferrable mode. Must be greater than 0.
**Example**:
.. code-block:: python
s3_to_gcs_op = S3ToGCSOperator(
task_id="s3_to_gcs_example",
bucket="my-s3-bucket",
prefix="data/customers-201804",
gcp_conn_id="google_cloud_default",
dest_gcs="gs://my.gcs.bucket/some/customers/",
replace=False,
gzip=True,
dag=my_dag,
)
Note that ``bucket``, ``prefix``, ``delimiter`` and ``dest_gcs`` are
templated, so you can use variables in them if you wish.
"""
[docs] template_fields: Sequence[str] = (
"bucket",
"prefix",
"delimiter",
"dest_gcs",
"google_impersonation_chain",
)
[docs] transfer_job_max_files_number = 1000
def __init__(
self,
*,
bucket,
prefix="",
apply_gcs_prefix=False,
delimiter="",
aws_conn_id="aws_default",
verify=None,
gcp_conn_id="google_cloud_default",
dest_gcs=None,
replace=False,
gzip=False,
google_impersonation_chain: str | Sequence[str] | None = None,
deferrable=conf.getboolean("operators", "default_deferrable", fallback=False),
poll_interval: int = 10,
**kwargs,
):
super().__init__(bucket=bucket, prefix=prefix, delimiter=delimiter, aws_conn_id=aws_conn_id, **kwargs)
self.apply_gcs_prefix = apply_gcs_prefix
self.gcp_conn_id = gcp_conn_id
self.dest_gcs = dest_gcs
self.replace = replace
self.verify = verify
self.gzip = gzip
self.google_impersonation_chain = google_impersonation_chain
self.deferrable = deferrable
if poll_interval <= 0:
raise ValueError("Invalid value for poll_interval. Expected value greater than 0")
self.poll_interval = poll_interval
def _check_inputs(self) -> None:
if self.dest_gcs and not gcs_object_is_directory(self.dest_gcs):
self.log.info(
"Destination Google Cloud Storage path is not a valid "
'"directory", define a path that ends with a slash "/" or '
"leave it empty for the root of the bucket."
)
raise AirflowException(
'The destination Google Cloud Storage path must end with a slash "/" or be empty.'
)
[docs] def execute(self, context: Context):
self._check_inputs()
# use the super method to list all the files in an S3 bucket/key
s3_objects = super().execute(context)
gcs_hook = GCSHook(
gcp_conn_id=self.gcp_conn_id,
impersonation_chain=self.google_impersonation_chain,
)
if not self.replace:
s3_objects = self.exclude_existing_objects(s3_objects=s3_objects, gcs_hook=gcs_hook)
s3_hook = S3Hook(aws_conn_id=self.aws_conn_id, verify=self.verify)
if not s3_objects:
self.log.info("In sync, no files needed to be uploaded to Google Cloud Storage")
elif self.deferrable:
self.transfer_files_async(s3_objects, gcs_hook, s3_hook)
else:
self.transfer_files(s3_objects, gcs_hook, s3_hook)
return s3_objects
[docs] def exclude_existing_objects(self, s3_objects: list[str], gcs_hook: GCSHook) -> list[str]:
"""Excludes from the list objects that already exist in GCS bucket."""
bucket_name, object_prefix = _parse_gcs_url(self.dest_gcs)
existing_gcs_objects = set(gcs_hook.list(bucket_name, prefix=object_prefix))
s3_paths = set(self.gcs_to_s3_object(gcs_object=gcs_object) for gcs_object in existing_gcs_objects)
s3_objects_reduced = list(set(s3_objects) - s3_paths)
if s3_objects_reduced:
self.log.info("%s files are going to be synced: %s.", len(s3_objects_reduced), s3_objects_reduced)
else:
self.log.info("There are no new files to sync. Have a nice day!")
return s3_objects_reduced
[docs] def s3_to_gcs_object(self, s3_object: str) -> str:
"""
Transforms S3 path to GCS path according to the operator's logic.
If apply_gcs_prefix == True then <s3_prefix><content> => <gcs_prefix><content>
If apply_gcs_prefix == False then <s3_prefix><content> => <gcs_prefix><s3_prefix><content>
"""
gcs_bucket, gcs_prefix = _parse_gcs_url(self.dest_gcs)
if self.apply_gcs_prefix:
gcs_object = s3_object.replace(self.prefix, gcs_prefix, 1)
return gcs_object
return gcs_prefix + s3_object
[docs] def gcs_to_s3_object(self, gcs_object: str) -> str:
"""
Transforms GCS path to S3 path according to the operator's logic.
If apply_gcs_prefix == True then <gcs_prefix><content> => <s3_prefix><content>
If apply_gcs_prefix == False then <gcs_prefix><s3_prefix><content> => <s3_prefix><content>
"""
gcs_bucket, gcs_prefix = _parse_gcs_url(self.dest_gcs)
s3_object = gcs_object.replace(gcs_prefix, "", 1)
if self.apply_gcs_prefix:
return self.prefix + s3_object
return s3_object
[docs] def transfer_files(self, s3_objects: list[str], gcs_hook: GCSHook, s3_hook: S3Hook) -> None:
if s3_objects:
dest_gcs_bucket, dest_gcs_object_prefix = _parse_gcs_url(self.dest_gcs)
for obj in s3_objects:
# GCS hook builds its own in-memory file, so we have to create
# and pass the path
file_object = s3_hook.get_key(obj, self.bucket)
with NamedTemporaryFile(mode="wb", delete=True) as file:
file_object.download_fileobj(file)
file.flush()
gcs_file = self.s3_to_gcs_object(s3_object=obj)
gcs_hook.upload(dest_gcs_bucket, gcs_file, file.name, gzip=self.gzip)
self.log.info("All done, uploaded %d files to Google Cloud Storage", len(s3_objects))
[docs] def transfer_files_async(self, files: list[str], gcs_hook: GCSHook, s3_hook: S3Hook) -> None:
"""Submits Google Cloud Storage Transfer Service job to copy files from AWS S3 to GCS."""
if not len(files):
raise ValueError("List of transferring files cannot be empty")
job_names = self.submit_transfer_jobs(files=files, gcs_hook=gcs_hook, s3_hook=s3_hook)
self.defer(
trigger=CloudStorageTransferServiceCreateJobsTrigger(
project_id=gcs_hook.project_id,
job_names=job_names,
poll_interval=self.poll_interval,
),
method_name="execute_complete",
)
[docs] def submit_transfer_jobs(self, files: list[str], gcs_hook: GCSHook, s3_hook: S3Hook) -> list[str]:
now = datetime.utcnow()
one_time_schedule = {"day": now.day, "month": now.month, "year": now.year}
gcs_bucket, gcs_prefix = _parse_gcs_url(self.dest_gcs)
config = s3_hook.conn_config
body: dict[str, Any] = {
PROJECT_ID: gcs_hook.project_id,
STATUS: GcpTransferJobsStatus.ENABLED,
SCHEDULE: {
SCHEDULE_START_DATE: one_time_schedule,
SCHEDULE_END_DATE: one_time_schedule,
},
TRANSFER_SPEC: {
AWS_S3_DATA_SOURCE: {
BUCKET_NAME: self.bucket,
AWS_ACCESS_KEY: {
ACCESS_KEY_ID: config.aws_access_key_id,
AWS_SECRET_ACCESS_KEY: config.aws_secret_access_key,
},
},
OBJECT_CONDITIONS: {
INCLUDE_PREFIXES: [],
},
GCS_DATA_SINK: {BUCKET_NAME: gcs_bucket, PATH: gcs_prefix},
TRANSFER_OPTIONS: {
OVERWRITE_OBJECTS_ALREADY_EXISTING_IN_SINK: self.replace,
},
},
}
# max size of the field 'transfer_job.transfer_spec.object_conditions.include_prefixes' is 1000,
# that's why we submit multiple jobs transferring 1000 files each.
# See documentation below
# https://cloud.google.com/storage-transfer/docs/reference/rest/v1/TransferSpec#ObjectConditions
chunk_size = self.transfer_job_max_files_number
job_names = []
transfer_hook = self.get_transfer_hook()
for i in range(0, len(files), chunk_size):
files_chunk = files[i : i + chunk_size]
body[TRANSFER_SPEC][OBJECT_CONDITIONS][INCLUDE_PREFIXES] = files_chunk
job = transfer_hook.create_transfer_job(body=body)
s = "s" if len(files_chunk) > 1 else ""
self.log.info(f"Submitted job {job['name']} to transfer {len(files_chunk)} file{s}")
job_names.append(job["name"])
if len(files) > chunk_size:
js = "s" if len(job_names) > 1 else ""
fs = "s" if len(files) > 1 else ""
self.log.info(f"Overall submitted {len(job_names)} job{js} to transfer {len(files)} file{fs}")
return job_names
[docs] def execute_complete(self, context: Context, event: dict[str, Any]) -> None:
"""
Callback for when the trigger fires - returns immediately.
Relies on trigger to throw an exception, otherwise it assumes execution was
successful.
"""
if event["status"] == "error":
raise AirflowException(event["message"])
self.log.info("%s completed with response %s ", self.task_id, event["message"])
[docs] def get_transfer_hook(self):
return CloudDataTransferServiceHook(
gcp_conn_id=self.gcp_conn_id,
impersonation_chain=self.google_impersonation_chain,
)
