taskflow datacat_integration.py

import os

from airflow import settings
from airflow.decorators import dag, task
from airflow.models import Variable
from airflow.models.connection import Connection
from airflow.providers.ssh.hooks.ssh import SSHHook
import pendulum

from b2shareoperator import download_file, get_file_list, get_object_md, get_objects

default_args = {"owner": "airflow"}


@dag(
    default_args=default_args,
    schedule=None,
    start_date=pendulum.today(),
    tags=["example", "datacat_integration"],
)
def taskflow_datacat_integration():
    @task(multiple_outputs=True)
    def extract(conn_id, **kwargs):
        connection = Connection.get_connection_from_secrets(conn_id)
        server = connection.get_uri()
        print(f"Retreiving data from {server}")

        params = kwargs["params"]
        if "oid" not in params:  # {"oid":"b38609df2b334ea296ea1857e568dbea"}
            print("Missing object id in pipeline parameters")
            lst = get_objects(server=server)
            flist = {o["id"]: [f["key"] for f in o["files"]] for o in lst}
            print(f"Objects on server: {flist}")
            return -1  # non zero exit code is a task failure

        oid = params["oid"]

        obj = get_object_md(server=server, oid=oid)
        print(f"Retrieved object {oid}: {obj}")
        flist = get_file_list(obj)
        return flist

    @task(multiple_outputs=True)
    def transform(flist: dict):
        name_mappings = {}
        tmp_dir = Variable.get("working_dir", default_var="/tmp/")
        print(f"Local working dir is: {tmp_dir}")

        for fname, url in flist.items():
            print(f"Processing: {fname} --> {url}")
            tmpname = download_file(url=url, target_dir=tmp_dir)
            name_mappings[fname] = tmpname
        return name_mappings

    @task()
    def load(connection_id, files: dict, **kwargs):
        print(f"Total files downloaded: {len(files)}")
        params = kwargs["params"]
        target = params.get("target", "/tmp/")

        print(f"Using {connection_id} connection")

        ssh_hook = SSHHook(ssh_conn_id=connection_id)
        with ssh_hook.get_conn() as ssh_client:
            sftp_client = ssh_client.open_sftp()
            for [truename, local] in files.items():
                print(
                    f"Copying {local} --> {connection_id}:{os.path.join(target, truename)}"
                )
                sftp_client.put(local, os.path.join(target, truename))
                # or separate cleanup task?
                os.unlink(local)

    conn_id = (
        "e3710075-9f8f-4ae0-a1c3-7d92c0182d19"  # created as copy of default_b2share
    )
    data = extract(conn_id)
    files = transform(data)
    load(connection_id=conn_id, files=files)


dag = taskflow_datacat_integration()