# Copyright (c) Streamlit Inc. (2018-2022) Snowflake Inc. (2022-2024)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import annotations
import os
import threading
from copy import deepcopy
from typing import (
Any,
Final,
ItemsView,
Iterator,
KeysView,
Mapping,
NoReturn,
ValuesView,
)
from blinker import Signal
import streamlit as st
import streamlit.watcher.path_watcher
from streamlit import file_util, runtime
from streamlit.logger import get_logger
_LOGGER: Final = get_logger(__name__)
SECRETS_FILE_LOCS: Final[list[str]] = [
file_util.get_streamlit_file_path("secrets.toml"),
# NOTE: The order here is important! Project-level secrets should overwrite global
# secrets.
file_util.get_project_streamlit_file_path("secrets.toml"),
]
def _missing_attr_error_message(attr_name: str) -> str:
return (
f'st.secrets has no attribute "{attr_name}". '
f"Did you forget to add it to secrets.toml or the app settings on Streamlit Cloud? "
f"More info: https://docs.streamlit.io/streamlit-cloud/get-started/deploy-an-app/connect-to-data-sources/secrets-management"
)
def _missing_key_error_message(key: str) -> str:
return (
f'st.secrets has no key "{key}". '
f"Did you forget to add it to secrets.toml or the app settings on Streamlit Cloud? "
f"More info: https://docs.streamlit.io/streamlit-cloud/get-started/deploy-an-app/connect-to-data-sources/secrets-management"
)
class AttrDict(Mapping[str, Any]):
"""
We use AttrDict to wrap up dictionary values from secrets
to provide dot access to nested secrets
"""
def __init__(self, value):
self.__dict__["__nested_secrets__"] = dict(value)
@staticmethod
def _maybe_wrap_in_attr_dict(value) -> Any:
if not isinstance(value, Mapping):
return value
else:
return AttrDict(value)
def __len__(self) -> int:
return len(self.__nested_secrets__)
def __iter__(self) -> Iterator[str]:
return iter(self.__nested_secrets__)
def __getitem__(self, key: str) -> Any:
try:
value = self.__nested_secrets__[key]
return self._maybe_wrap_in_attr_dict(value)
except KeyError:
raise KeyError(_missing_key_error_message(key))
def __getattr__(self, attr_name: str) -> Any:
try:
value = self.__nested_secrets__[attr_name]
return self._maybe_wrap_in_attr_dict(value)
except KeyError:
raise AttributeError(_missing_attr_error_message(attr_name))
def __repr__(self):
return repr(self.__nested_secrets__)
def __setitem__(self, key, value) -> NoReturn:
raise TypeError("Secrets does not support item assignment.")
def __setattr__(self, key, value) -> NoReturn:
raise TypeError("Secrets does not support attribute assignment.")
def to_dict(self) -> dict[str, Any]:
return deepcopy(self.__nested_secrets__)
class Secrets(Mapping[str, Any]):
"""A dict-like class that stores secrets.
Parses secrets.toml on-demand. Cannot be externally mutated.
Safe to use from multiple threads.
"""
def __init__(self, file_paths: list[str]):
# Our secrets dict.
self._secrets: Mapping[str, Any] | None = None
self._lock = threading.RLock()
self._file_watchers_installed = False
self._file_paths = file_paths
self.file_change_listener = Signal(
doc="Emitted when a `secrets.toml` file has been changed."
)
def load_if_toml_exists(self) -> bool:
"""Load secrets.toml files from disk if they exists. If none exist,
no exception will be raised. (If a file exists but is malformed,
an exception *will* be raised.)
Returns True if a secrets.toml file was successfully parsed, False otherwise.
Thread-safe.
"""
try:
self._parse(print_exceptions=False)
return True
except FileNotFoundError:
# No secrets.toml files exist. That's fine.
return False
def _reset(self) -> None:
"""Clear the secrets dictionary and remove any secrets that were
added to os.environ.
Thread-safe.
"""
with self._lock:
if self._secrets is None:
return
for k, v in self._secrets.items():
self._maybe_delete_environment_variable(k, v)
self._secrets = None
def _parse(self, print_exceptions: bool) -> Mapping[str, Any]:
"""Parse our secrets.toml files if they're not already parsed.
This function is safe to call from multiple threads.
Parameters
----------
print_exceptions : bool
If True, then exceptions will be printed with `st.error` before
being re-raised.
Raises
------
FileNotFoundError
Raised if secrets.toml doesn't exist.
"""
# Avoid taking a lock for the common case where secrets are already
# loaded.
secrets = self._secrets
if secrets is not None:
return secrets
with self._lock:
if self._secrets is not None:
return self._secrets
# It's fine for a user to only have one secrets.toml file defined, so
# we ignore individual FileNotFoundErrors when attempting to read files
# below and only raise an exception if we weren't able read *any* secrets
# file.
found_secrets_file = False
secrets = {}
for path in self._file_paths:
try:
with open(path, encoding="utf-8") as f:
secrets_file_str = f.read()
found_secrets_file = True
except FileNotFoundError:
continue
try:
import toml
secrets.update(toml.loads(secrets_file_str))
except:
if print_exceptions:
st.error(f"Error parsing secrets file at {path}")
raise
if not found_secrets_file:
err_msg = f"No secrets files found. Valid paths for a secrets.toml file are: {', '.join(self._file_paths)}"
if print_exceptions:
st.error(err_msg)
raise FileNotFoundError(err_msg)
if len([p for p in self._file_paths if os.path.exists(p)]) > 1:
_LOGGER.info(
f"Secrets found in multiple locations: {', '.join(self._file_paths)}. "
"When multiple secret.toml files exist, local secrets will take precedence over global secrets."
)
for k, v in secrets.items():
self._maybe_set_environment_variable(k, v)
self._secrets = secrets
self._maybe_install_file_watchers()
return self._secrets
@staticmethod
def _maybe_set_environment_variable(k: Any, v: Any) -> None:
"""Add the given key/value pair to os.environ if the value
is a string, int, or float.
"""
value_type = type(v)
if value_type in (str, int, float):
os.environ[k] = str(v)
@staticmethod
def _maybe_delete_environment_variable(k: Any, v: Any) -> None:
"""Remove the given key/value pair from os.environ if the value
is a string, int, or float.
"""
value_type = type(v)
if value_type in (str, int, float) and os.environ.get(k) == v:
del os.environ[k]
def _maybe_install_file_watchers(self) -> None:
with self._lock:
if self._file_watchers_installed:
return
for path in self._file_paths:
try:
streamlit.watcher.path_watcher.watch_file(
path,
self._on_secrets_file_changed,
watcher_type="poll",
)
except FileNotFoundError:
# A user may only have one secrets.toml file defined, so we'd expect
# FileNotFoundErrors to be raised when attempting to install a
# watcher on the nonexistent ones.
pass
# We set file_watchers_installed to True even if the installation attempt
# failed to avoid repeatedly trying to install it.
self._file_watchers_installed = True
def _on_secrets_file_changed(self, changed_file_path) -> None:
with self._lock:
_LOGGER.debug("Secrets file %s changed, reloading", changed_file_path)
self._reset()
self._parse(print_exceptions=True)
# Emit a signal to notify receivers that the `secrets.toml` file
# has been changed.
self.file_change_listener.send()
def __getattr__(self, key: str) -> Any:
"""Return the value with the given key. If no such key
exists, raise an AttributeError.
Thread-safe.
"""
try:
value = self._parse(True)[key]
if not isinstance(value, Mapping):
return value
else:
return AttrDict(value)
# We add FileNotFoundError since __getattr__ is expected to only raise
# AttributeError. Without handling FileNotFoundError, unittests.mocks
# fails during mock creation on Python3.9
except (KeyError, FileNotFoundError):
raise AttributeError(_missing_attr_error_message(key))
def __getitem__(self, key: str) -> Any:
"""Return the value with the given key. If no such key
exists, raise a KeyError.
Thread-safe.
"""
try:
value = self._parse(True)[key]
if not isinstance(value, Mapping):
return value
else:
return AttrDict(value)
except KeyError:
raise KeyError(_missing_key_error_message(key))
def __repr__(self) -> str:
# If the runtime is NOT initialized, it is a method call outside
# the streamlit app, so we avoid reading the secrets file as it may not exist.
# If the runtime is initialized, display the contents of the file and
# the file must already exist.
"""A string representation of the contents of the dict. Thread-safe."""
if not runtime.exists():
return f"{self.__class__.__name__}(file_paths={self._file_paths!r})"
return repr(self._parse(True))
def __len__(self) -> int:
"""The number of entries in the dict. Thread-safe."""
return len(self._parse(True))
def has_key(self, k: str) -> bool:
"""True if the given key is in the dict. Thread-safe."""
return k in self._parse(True)
def keys(self) -> KeysView[str]:
"""A view of the keys in the dict. Thread-safe."""
return self._parse(True).keys()
def values(self) -> ValuesView[Any]:
"""A view of the values in the dict. Thread-safe."""
return self._parse(True).values()
def items(self) -> ItemsView[str, Any]:
"""A view of the key-value items in the dict. Thread-safe."""
return self._parse(True).items()
def __contains__(self, key: Any) -> bool:
"""True if the given key is in the dict. Thread-safe."""
return key in self._parse(True)
def __iter__(self) -> Iterator[str]:
"""An iterator over the keys in the dict. Thread-safe."""
return iter(self._parse(True))
secrets_singleton: Final = Secrets(SECRETS_FILE_LOCS)