airflow-dags/reference/providers/ftp/hooks/ftp.py

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import datetime
import ftplib
import os.path
from typing import Any, List, Optional

from airflow.hooks.base import BaseHook


class FTPHook(BaseHook):
    """
    Interact with FTP.

    Errors that may occur throughout but should be handled downstream.
    You can specify mode for data transfers in the extra field of your
    connection as ``{"passive": "true"}``.
    """

    conn_name_attr = "ftp_conn_id"
    default_conn_name = "ftp_default"
    conn_type = "ftp"
    hook_name = "FTP"

    def __init__(self, ftp_conn_id: str = default_conn_name) -> None:
        super().__init__()
        self.ftp_conn_id = ftp_conn_id
        self.conn: Optional[ftplib.FTP] = None

    def __enter__(self):
        return self

    def __exit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None:
        if self.conn is not None:
            self.close_conn()

    def get_conn(self) -> ftplib.FTP:
        """Returns a FTP connection object"""
        if self.conn is None:
            params = self.get_connection(self.ftp_conn_id)
            pasv = params.extra_dejson.get("passive", True)
            self.conn = ftplib.FTP(params.host, params.login, params.password)
            self.conn.set_pasv(pasv)

        return self.conn

    def close_conn(self):
        """
        Closes the connection. An error will occur if the
        connection wasn't ever opened.
        """
        conn = self.conn
        conn.quit()
        self.conn = None

    def describe_directory(self, path: str) -> dict:
        """
        Returns a dictionary of {filename: {attributes}} for all files
        on the remote system (where the MLSD command is supported).

        :param path: full path to the remote directory
        :type path: str
        """
        conn = self.get_conn()
        conn.cwd(path)
        files = dict(conn.mlsd())
        return files

    def list_directory(self, path: str) -> List[str]:
        """
        Returns a list of files on the remote system.

        :param path: full path to the remote directory to list
        :type path: str
        """
        conn = self.get_conn()
        conn.cwd(path)

        files = conn.nlst()
        return files

    def create_directory(self, path: str) -> None:
        """
        Creates a directory on the remote system.

        :param path: full path to the remote directory to create
        :type path: str
        """
        conn = self.get_conn()
        conn.mkd(path)

    def delete_directory(self, path: str) -> None:
        """
        Deletes a directory on the remote system.

        :param path: full path to the remote directory to delete
        :type path: str
        """
        conn = self.get_conn()
        conn.rmd(path)

    def retrieve_file(self, remote_full_path, local_full_path_or_buffer, callback=None):
        """
        Transfers the remote file to a local location.

        If local_full_path_or_buffer is a string path, the file will be put
        at that location; if it is a file-like buffer, the file will
        be written to the buffer but not closed.

        :param remote_full_path: full path to the remote file
        :type remote_full_path: str
        :param local_full_path_or_buffer: full path to the local file or a
            file-like buffer
        :type local_full_path_or_buffer: str or file-like buffer
        :param callback: callback which is called each time a block of data
            is read. if you do not use a callback, these blocks will be written
            to the file or buffer passed in. if you do pass in a callback, note
            that writing to a file or buffer will need to be handled inside the
            callback.
            [default: output_handle.write()]
        :type callback: callable

        .. code-block:: python

            hook = FTPHook(ftp_conn_id='my_conn')

            remote_path = '/path/to/remote/file'
            local_path = '/path/to/local/file'

            # with a custom callback (in this case displaying progress on each read)
            def print_progress(percent_progress):
                self.log.info('Percent Downloaded: %s%%' % percent_progress)

            total_downloaded = 0
            total_file_size = hook.get_size(remote_path)
            output_handle = open(local_path, 'wb')
            def write_to_file_with_progress(data):
                total_downloaded += len(data)
                output_handle.write(data)
                percent_progress = (total_downloaded / total_file_size) * 100
                print_progress(percent_progress)
            hook.retrieve_file(remote_path, None, callback=write_to_file_with_progress)

            # without a custom callback data is written to the local_path
            hook.retrieve_file(remote_path, local_path)

        """
        conn = self.get_conn()

        is_path = isinstance(local_full_path_or_buffer, str)

        # without a callback, default to writing to a user-provided file or
        # file-like buffer
        if not callback:
            if is_path:
                output_handle = open(local_full_path_or_buffer, "wb")
            else:
                output_handle = local_full_path_or_buffer
            callback = output_handle.write
        else:
            output_handle = None

        remote_path, remote_file_name = os.path.split(remote_full_path)
        conn.cwd(remote_path)
        self.log.info("Retrieving file from FTP: %s", remote_full_path)
        conn.retrbinary(f"RETR {remote_file_name}", callback)
        self.log.info("Finished retrieving file from FTP: %s", remote_full_path)

        if is_path and output_handle:
            output_handle.close()

    def store_file(self, remote_full_path: str, local_full_path_or_buffer: Any) -> None:
        """
        Transfers a local file to the remote location.

        If local_full_path_or_buffer is a string path, the file will be read
        from that location; if it is a file-like buffer, the file will
        be read from the buffer but not closed.

        :param remote_full_path: full path to the remote file
        :type remote_full_path: str
        :param local_full_path_or_buffer: full path to the local file or a
            file-like buffer
        :type local_full_path_or_buffer: str or file-like buffer
        """
        conn = self.get_conn()

        is_path = isinstance(local_full_path_or_buffer, str)

        if is_path:
            input_handle = open(local_full_path_or_buffer, "rb")
        else:
            input_handle = local_full_path_or_buffer
        remote_path, remote_file_name = os.path.split(remote_full_path)
        conn.cwd(remote_path)
        conn.storbinary(f"STOR {remote_file_name}", input_handle)

        if is_path:
            input_handle.close()

    def delete_file(self, path: str) -> None:
        """
        Removes a file on the FTP Server.

        :param path: full path to the remote file
        :type path: str
        """
        conn = self.get_conn()
        conn.delete(path)

    def rename(self, from_name: str, to_name: str) -> str:
        """
        Rename a file.

        :param from_name: rename file from name
        :param to_name: rename file to name
        """
        conn = self.get_conn()
        return conn.rename(from_name, to_name)

    def get_mod_time(self, path: str) -> datetime.datetime:
        """
        Returns a datetime object representing the last time the file was modified

        :param path: remote file path
        :type path: str
        """
        conn = self.get_conn()
        ftp_mdtm = conn.sendcmd("MDTM " + path)
        time_val = ftp_mdtm[4:]
        # time_val optionally has microseconds
        try:
            return datetime.datetime.strptime(time_val, "%Y%m%d%H%M%S.%f")
        except ValueError:
            return datetime.datetime.strptime(time_val, "%Y%m%d%H%M%S")

    def get_size(self, path: str) -> Optional[int]:
        """
        Returns the size of a file (in bytes)

        :param path: remote file path
        :type path: str
        """
        conn = self.get_conn()
        size = conn.size(path)
        return int(size) if size else None


class FTPSHook(FTPHook):
    """Interact with FTPS."""

    def get_conn(self) -> ftplib.FTP:
        """Returns a FTPS connection object."""
        if self.conn is None:
            params = self.get_connection(self.ftp_conn_id)
            pasv = params.extra_dejson.get("passive", True)

            if params.port:
                ftplib.FTP_TLS.port = params.port

            self.conn = ftplib.FTP_TLS(params.host, params.login, params.password)
            self.conn.set_pasv(pasv)

        return self.conn