Coverage for airflow.operators.s3_file_transform_operator : 33%

import logging 

from tempfile import NamedTemporaryFile 

import subprocess 

from airflow.utils import AirflowException 

from airflow.hooks import S3Hook 

from airflow.models import BaseOperator 

from airflow.utils import apply_defaults 

class S3FileTransformOperator(BaseOperator): 

    """ 

    Copies data from a source S3 location to a temporary location on the 

    local filesystem. Runs a transformation on this file as specified by 

    the transformation script and uploads the output to a destination S3 

    location. 

    The locations of the source and the destination files in the local 

    filesystem is provided as an first and second arguments to the 

    transformation script. The transformation script is expected to read the 

    data from source , transform it and write the output to the local 

    destination file. The operator then takes over control and uploads the 

    local destination file to S3. 

    :param source_s3_key: The key to be retrieved from S3 

    :type source_s3_key: str 

    :param source_s3_conn_id: source s3 connection 

    :type source_s3_conn_id: str 

    :param dest_s3_key: The key to be written from S3 

    :type dest_s3_key: str 

    :param dest_s3_conn_id: destination s3 connection 

    :type dest_s3_conn_id: str 

    :param replace: Replace dest S3 key if it already exists 

    :type replace: bool 

    :param transform_script: location of the executable transformation script 

    :type transform_script: str 

    """ 

    template_fields = ('source_s3_key', 'dest_s3_key') 

    template_ext = () 

    ui_color = '#f9c915' 

    @apply_defaults 

    def __init__( 

            self, 

            source_s3_key, 

            dest_s3_key, 

            transform_script, 

            source_s3_conn_id='s3_default', 

            dest_s3_conn_id='s3_default', 

            replace=False, 

            *args, **kwargs): 

        super(S3FileTransformOperator, self).__init__(*args, **kwargs) 

        self.source_s3_key = source_s3_key 

        self.source_s3_conn_id = source_s3_conn_id 

        self.dest_s3_key = dest_s3_key 

        self.dest_s3_conn_id = dest_s3_conn_id 

        self.replace = replace 

        self.transform_script = transform_script 

        self.source_s3 = S3Hook(s3_conn_id=source_s3_conn_id) 

        self.dest_s3 = S3Hook(s3_conn_id=dest_s3_conn_id) 

    def execute(self, context): 

        logging.info("Downloading source S3 file {0}" 

                     "".format(self.source_s3_key)) 

        if not self.source_s3.check_for_key(self.source_s3_key): 

            raise AirflowException("The source key {0} does not exist" 

                            "".format(self.source_s3_key)) 

        source_s3_key_object = self.source_s3.get_key(self.source_s3_key) 

        with NamedTemporaryFile("w") as f_source, NamedTemporaryFile("w") as f_dest: 

            logging.info("Dumping S3 file {0} contents to local file {1}" 

                         "".format(self.source_s3_key, f_source.name)) 

            source_s3_key_object.get_contents_to_file(f_source) 

            f_source.flush() 

            self.source_s3.connection.close() 

            transform_script_process = subprocess.Popen( 

                [self.transform_script, f_source.name, f_dest.name], 

                stdout=subprocess.PIPE, stderr=subprocess.PIPE) 

            (transform_script_stdoutdata, transform_script_stderrdata) = transform_script_process.communicate() 

            logging.info("Transform script stdout " 

                         "" + transform_script_stdoutdata) 

            if transform_script_process.returncode > 0: 

                raise AirflowException("Transform script failed " 

                                "" + transform_script_stderrdata) 

            else: 

                logging.info("Transform script successful." 

                             "Output temporarily located at {0}" 

                             "".format(f_dest.name)) 

            logging.info("Uploading transformed file to S3") 

            f_dest.flush() 

            self.dest_s3.load_file( 

                filename=f_dest.name, 

                key=self.dest_s3_key, 

                replace=self.replace 

            ) 

            logging.info("Upload successful") 

            self.dest_s3.connection.close()