Source code for airflow.secrets.cache

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from __future__ import annotations

import datetime
import multiprocessing

from airflow.configuration import conf

[docs]class SecretCache: """A static class to manage the global secret cache.""" __manager: multiprocessing.managers.SyncManager | None = None _cache: dict[str, _CacheValue] | None = None _ttl: datetime.timedelta class NotPresentException(Exception): """Raised when a key is not present in the cache.""" class _CacheValue: def __init__(self, value: str | None) -> None: self.value = value = datetime.datetime.utcnow() def is_expired(self, ttl: datetime.timedelta) -> bool: return datetime.datetime.utcnow() - > ttl _VARIABLE_PREFIX = "__v_" _CONNECTION_PREFIX = "__c_" @classmethod
[docs] def init(cls): """ Initialize the cache, provided the configuration allows it. Safe to call several times. """ if cls._cache is not None: return use_cache = conf.getboolean(section="secrets", key="use_cache", fallback=False) if not use_cache: return if cls.__manager is None: # it is not really necessary to save the manager, but doing so allows to reuse it between tests, # making them run a lot faster because this operation takes ~300ms each time cls.__manager = multiprocessing.Manager() cls._cache = cls.__manager.dict() ttl_seconds = conf.getint(section="secrets", key="cache_ttl_seconds", fallback=15 * 60) cls._ttl = datetime.timedelta(seconds=ttl_seconds)
[docs] def reset(cls): """Use for test purposes only.""" cls._cache = None
[docs] def get_variable(cls, key: str) -> str | None: """ Try to get the value associated with the key from the cache. :return: The saved value (which can be None) if present in cache and not expired, a NotPresent exception otherwise. """ return cls._get(key, cls._VARIABLE_PREFIX)
[docs] def get_connection_uri(cls, conn_id: str) -> str: """ Try to get the uri associated with the conn_id from the cache. :return: The saved uri if present in cache and not expired, a NotPresent exception otherwise. """ val = cls._get(conn_id, cls._CONNECTION_PREFIX) if val: # there shouldn't be any empty entries in the connections cache, but we enforce it here. return val raise cls.NotPresentException
@classmethod def _get(cls, key: str, prefix: str) -> str | None: if cls._cache is None: # using an exception for misses allow to meaningfully cache None values raise cls.NotPresentException val = cls._cache.get(f"{prefix}{key}") if val and not val.is_expired(cls._ttl): return val.value raise cls.NotPresentException @classmethod
[docs] def save_variable(cls, key: str, value: str | None): """Save the value for that key in the cache, if initialized.""" cls._save(key, value, cls._VARIABLE_PREFIX)
[docs] def save_connection_uri(cls, conn_id: str, uri: str): """Save the uri representation for that connection in the cache, if initialized.""" if uri is None: # connections raise exceptions if not present, so we shouldn't have any None value to save. return cls._save(conn_id, uri, cls._CONNECTION_PREFIX)
@classmethod def _save(cls, key: str, value: str | None, prefix: str): if cls._cache is not None: cls._cache[f"{prefix}{key}"] = cls._CacheValue(value) @classmethod
[docs] def invalidate_variable(cls, key: str): """Invalidate (actually removes) the value stored in the cache for that Variable.""" if cls._cache is not None: # second arg ensures no exception if key is absent cls._cache.pop(f"{cls._VARIABLE_PREFIX}{key}", None)

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