Source code for airflow.models.variable

# -*- coding: utf-8 -*-
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import json
from builtins import bytes
from typing import Any

from sqlalchemy import Column, Integer, String, Text, Boolean
from sqlalchemy.ext.declarative import declared_attr
from sqlalchemy.orm import synonym

from airflow.models.base import Base, ID_LEN
from airflow.models.crypto import get_fernet, InvalidFernetToken
from airflow.utils.db import provide_session
from airflow.utils.log.logging_mixin import LoggingMixin


[docs]class Variable(Base, LoggingMixin):
[docs] __tablename__ = "variable"
[docs] __NO_DEFAULT_SENTINEL = object()
[docs] id = Column(Integer, primary_key=True)
[docs] key = Column(String(ID_LEN), unique=True)
[docs] _val = Column('val', Text)
[docs] is_encrypted = Column(Boolean, unique=False, default=False)
[docs] def __repr__(self): # Hiding the value return '{} : {}'.format(self.key, self._val)
[docs] def get_val(self): log = LoggingMixin().log if self._val and self.is_encrypted: try: fernet = get_fernet() return fernet.decrypt(bytes(self._val, 'utf-8')).decode() except InvalidFernetToken: log.error("Can't decrypt _val for key={}, invalid token " "or value".format(self.key)) return None except Exception: log.error("Can't decrypt _val for key={}, FERNET_KEY " "configuration missing".format(self.key)) return None else: return self._val
[docs] def set_val(self, value): if value: fernet = get_fernet() self._val = fernet.encrypt(bytes(value, 'utf-8')).decode() self.is_encrypted = fernet.is_encrypted else: self._val = None self.is_encrypted = False
@declared_attr
[docs] def val(cls): return synonym('_val', descriptor=property(cls.get_val, cls.set_val))
@classmethod
[docs] def setdefault(cls, key, default, deserialize_json=False): """ Like a Python builtin dict object, setdefault returns the current value for a key, and if it isn't there, stores the default value and returns it. :param key: Dict key for this Variable :type key: str :param default: Default value to set and return if the variable isn't already in the DB :type default: Mixed :param deserialize_json: Store this as a JSON encoded value in the DB and un-encode it when retrieving a value :return: Mixed """ obj = Variable.get(key, default_var=None, deserialize_json=deserialize_json) if obj is None: if default is not None: Variable.set(key, default, serialize_json=deserialize_json) return default else: raise ValueError('Default Value must be set') else: return obj
@classmethod @provide_session
[docs] def get( cls, key, # type: str default_var=__NO_DEFAULT_SENTINEL, # type: Any deserialize_json=False, # type: bool session=None ): obj = session.query(cls).filter(cls.key == key).first() if obj is None: if default_var is not cls.__NO_DEFAULT_SENTINEL: return default_var else: raise KeyError('Variable {} does not exist'.format(key)) else: if deserialize_json: return json.loads(obj.val) else: return obj.val
@classmethod @provide_session
[docs] def set( cls, key, # type: str value, # type: Any serialize_json=False, # type: bool session=None ): if serialize_json: stored_value = json.dumps(value, indent=2, separators=(',', ': ')) else: stored_value = str(value) Variable.delete(key) session.add(Variable(key=key, val=stored_value)) # type: ignore session.flush()
@classmethod @provide_session
[docs] def delete(cls, key, session=None): session.query(cls).filter(cls.key == key).delete()
[docs] def rotate_fernet_key(self): fernet = get_fernet() if self._val and self.is_encrypted: self._val = fernet.rotate(self._val.encode('utf-8')).decode()