Source code for airflow.secrets.local_filesystem

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Objects relating to retrieving connections and variables from local file
import json
import logging
import os
from collections import defaultdict

import funcsigs
import six

from airflow.exceptions import AirflowException, AirflowFileParseException, file_syntax_error
from airflow.secrets.base_secrets import BaseSecretsBackend
from airflow.utils.file import COMMENT_PATTERN
from airflow.utils.log.logging_mixin import LoggingMixin

[docs]log = logging.getLogger(__name__)
[docs]def get_connection_parameter_names(): """Returns :class:`airflow.models.connection.Connection` constructor parameters.""" from airflow.models.connection import Connection return {k for k in funcsigs.signature(Connection.__init__).parameters.keys() if k != "self"}
[docs]def _parse_env_file(file_path): """ Parse a file in the ``.env '' format. .. code-block:: text MY_CONN_ID=my-conn-type://my-login:my-pa%2Fssword@my-host:5432/my-schema?param1=val1&param2=val2 :param file_path: The location of the file that will be processed. :type file_path: str :return: Tuple with mapping of key and list of values and list of syntax errors """ with open(file_path) as f: content = secrets = defaultdict(list) errors = [] for line_no, line in enumerate(content.splitlines(), 1): if not line: # Ignore empty line continue if COMMENT_PATTERN.match(line): # Ignore comments continue var_parts = line.split("=", 2) if len(var_parts) != 2: errors.append( file_syntax_error( line_no=line_no, message='Invalid line format. The line should contain at least one equal sign ("=").', ) ) continue key, value = var_parts if not key: errors.append(file_syntax_error(line_no=line_no, message="Invalid line format. Key is empty.",)) secrets[key].append(value) return secrets, errors
[docs]def _parse_json_file(file_path): """ Parse a file in the JSON format. :param file_path: The location of the file that will be processed. :type file_path: str :return: Tuple with mapping of key and list of values and list of syntax errors """ with open(file_path) as f: content = if not content: return {}, [file_syntax_error(line_no=1, message="The file is empty.")] try: secrets = json.loads(content) except ValueError as e: return {}, [file_syntax_error(line_no=1, message=str(e))] if not isinstance(secrets, dict): return {}, [file_syntax_error(line_no=1, message="The file should contain the object.")] return secrets, []
[docs]FILE_PARSERS = { "env": _parse_env_file, "json": _parse_json_file,
[docs]def _parse_secret_file(file_path): """ Based on the file extension format, selects a parser, and parses the file. :param file_path: The location of the file that will be processed. :type file_path: str :return: Map of secret key (e.g. connection ID) and value. """ if not os.path.exists(file_path): raise AirflowException( "File {} was not found. Check the configuration of your Secrets backend.".format(file_path) ) log.debug("Parsing file: %s", file_path) ext = file_path.rsplit(".", 2)[-1].lower() if ext not in FILE_PARSERS: raise AirflowException("Unsupported file format. The file must have the extension .env or .json") secrets, parse_errors = FILE_PARSERS[ext](file_path) log.debug("Parsed file: len(parse_errors)=%d, len(secrets)=%d", len(parse_errors), len(secrets)) if parse_errors: raise AirflowFileParseException( "Failed to load the secret file.", file_path=file_path, parse_errors=parse_errors ) return secrets
[docs]def _create_connection(conn_id, value): """ Creates a connection based on a URL or JSON object. """ from airflow.models.connection import Connection if isinstance(value, six.string_types): return Connection(conn_id=conn_id, uri=value) if isinstance(value, dict): connection_parameter_names = get_connection_parameter_names() current_keys = set(value.keys()) if not current_keys.issubset(connection_parameter_names): illegal_keys = current_keys - connection_parameter_names illegal_keys_list = ", ".join(illegal_keys) raise AirflowException( "The object have illegal keys: {}." "The dictionary can only contain the following keys: {}".format( illegal_keys_list, connection_parameter_names ) ) if "conn_id" in current_keys and conn_id != value["conn_id"]: raise AirflowException( "Mismatch conn_id. " "The dictionary key has the value: " + value['conn_id'] + ". " "The item has the value: " + conn_id + " ." ) value["conn_id"] = conn_id return Connection(**value) raise AirflowException( "Unexpected value type: {}" ". The connection can only be defined using a string or object.".format(type(value))
[docs]def load_variables(file_path): """ Load variables from a text file. Both ``JSON`` and ``.env`` files are supported. :param file_path: The location of the file that will be processed. :type file_path: str :rtype: dict[str, list[str]] """ log.debug("Loading variables from a text file") secrets = _parse_secret_file(file_path) invalid_keys = [key for key, values in secrets.items() if isinstance(values, list) and len(values) != 1] if invalid_keys: raise AirflowException( 'The "{}" file contains multiple values for keys: {}'.format(file_path, invalid_keys) ) variables = {key: values[0] if isinstance(values, list) else values for key, values in secrets.items()} log.debug("Loaded %d variables: ", len(variables)) return variables
[docs]def load_connections(file_path): """ Load connection from text file. Both ``JSON`` and ``.env`` files are supported. :return: A dictionary where the key contains a connection ID and the value contains a list of connections. :rtype: list[str, list[airflow.models.connection.Connection]] """ log.debug("Loading connection") secrets = _parse_secret_file(file_path) connections_by_conn_id = defaultdict(list) for key, secret_values in list(secrets.items()): if isinstance(secret_values, list): for secret_value in secret_values: connections_by_conn_id[key].append(_create_connection(key, secret_value)) else: connections_by_conn_id[key].append(_create_connection(key, secret_values)) num_conn = sum(map(len, connections_by_conn_id.values())) log.debug("Loaded %d connections", num_conn) return connections_by_conn_id
[docs]class LocalFilesystemBackend(BaseSecretsBackend, LoggingMixin): """ Retrieves Connection objects and Variables from local files Both ``JSON`` and ``.env`` files are supported. :param variables_file_path: File location with variables data. :type variables_file_path: str :param connections_file_path: File location with connection data. :type connections_file_path: str """ def __init__( self, variables_file_path=None, connections_file_path=None ): super(LocalFilesystemBackend, self).__init__() self.variables_file = variables_file_path self.connections_file = connections_file_path @property
[docs] def _local_variables(self): if not self.variables_file: self.log.debug("The file for variables is not specified. Skipping") # The user may not specify any file. return {} secrets = load_variables(self.variables_file) return secrets
[docs] def _local_connections(self): if not self.connections_file: self.log.debug("The file for connection is not specified. Skipping") # The user may not specify any file. return {} return load_connections(self.connections_file)
[docs] def get_connections(self, conn_id): return self._local_connections.get(conn_id) or []
[docs] def get_variable(self, key): return self._local_variables.get(key)

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