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AWS SSM Parameter retrieval and caching utility
"""
from __future__ import annotations
import logging
import os
import warnings
from typing import TYPE_CHECKING, Any, Literal, overload
import boto3
from aws_lambda_powertools.shared import constants
from aws_lambda_powertools.shared.functions import (
resolve_max_age,
resolve_truthy_env_var_choice,
slice_dictionary,
)
from aws_lambda_powertools.utilities.parameters.base import (
BaseProvider,
transform_value,
)
from aws_lambda_powertools.utilities.parameters.constants import (
DEFAULT_MAX_AGE_SECS,
DEFAULT_PROVIDERS,
SSM_PARAMETER_TIER,
SSM_PARAMETER_TYPES,
)
from aws_lambda_powertools.utilities.parameters.exceptions import GetParameterError, SetParameterError
from aws_lambda_powertools.warnings import PowertoolsDeprecationWarning
if TYPE_CHECKING:
from botocore.config import Config
from mypy_boto3_ssm.client import SSMClient
from mypy_boto3_ssm.type_defs import GetParametersResultTypeDef, PutParameterResultTypeDef
from aws_lambda_powertools.utilities.parameters.types import TransformOptions
logger = logging.getLogger(__name__)
class SSMProvider(BaseProvider):
"""
AWS Systems Manager Parameter Store Provider
Parameters
----------
config: botocore.config.Config, optional
Botocore configuration to pass during client initialization
boto3_session : boto3.session.Session, optional
Boto3 session to create a boto3_client from
boto3_client: SSMClient, optional
Boto3 SSM Client to use, boto3_session will be ignored if both are provided
Example
-------
**Retrieves a parameter value from Systems Manager Parameter Store**
>>> from aws_lambda_powertools.utilities.parameters import SSMProvider
>>> ssm_provider = SSMProvider()
>>>
>>> value = ssm_provider.get("/my/parameter")
>>>
>>> print(value)
My parameter value
**Retrieves a parameter value from Systems Manager Parameter Store in another AWS region**
>>> from botocore.config import Config
>>> from aws_lambda_powertools.utilities.parameters import SSMProvider
>>>
>>> config = Config(region_name="us-west-1")
>>> ssm_provider = SSMProvider(config=config)
>>>
>>> value = ssm_provider.get("/my/parameter")
>>>
>>> print(value)
My parameter value
**Retrieves multiple parameter values from Systems Manager Parameter Store using a path prefix**
>>> from aws_lambda_powertools.utilities.parameters import SSMProvider
>>> ssm_provider = SSMProvider()
>>>
>>> values = ssm_provider.get_multiple("/my/path/prefix")
>>>
>>> for key, value in values.items():
... print(key, value)
/my/path/prefix/a Parameter value a
/my/path/prefix/b Parameter value b
/my/path/prefix/c Parameter value c
**Retrieves multiple parameter values from Systems Manager Parameter Store passing options to the SDK call**
>>> from aws_lambda_powertools.utilities.parameters import SSMProvider
>>> ssm_provider = SSMProvider()
>>>
>>> values = ssm_provider.get_multiple("/my/path/prefix", MaxResults=10)
>>>
>>> for key, value in values.items():
... print(key, value)
/my/path/prefix/a Parameter value a
/my/path/prefix/b Parameter value b
/my/path/prefix/c Parameter value c
"""
_MAX_GET_PARAMETERS_ITEM = 10
_ERRORS_KEY = "_errors"
def __init__(
self,
config: Config | None = None,
boto_config: Config | None = None,
boto3_session: boto3.session.Session | None = None,
boto3_client: SSMClient | None = None,
):
"""
Initialize the SSM Parameter Store client
"""
if config:
warnings.warn(
message="The 'config' parameter is deprecated in V3 and will be removed in V4. "
"Please use 'boto_config' instead.",
category=PowertoolsDeprecationWarning,
stacklevel=2,
)
if boto3_client is None:
boto3_session = boto3_session or boto3.session.Session()
boto3_client = boto3_session.client("ssm", config=boto_config or config)
self.client = boto3_client
super().__init__(client=self.client)
def get_multiple( # type: ignore[override]
self,
path: str,
max_age: int | None = None,
transform: TransformOptions = None,
raise_on_transform_error: bool = False,
decrypt: bool | None = None,
force_fetch: bool = False,
recursive: bool = False,
**sdk_options,
) -> dict[str, str] | dict[str, bytes] | dict[str, dict]:
"""
Retrieve multiple parameters based on a path prefix
Parameters
----------
path: str
Parameter path used to retrieve multiple parameters
max_age: int, optional
Maximum age of the cached value
transform: str, optional
Optional transformation of the parameter value. Supported values
are "json" for JSON strings, "binary" for base 64 encoded
values or "auto" which looks at the attribute key to determine the type.
raise_on_transform_error: bool, optional
Raises an exception if any transform fails, otherwise this will
return a None value for each transform that failed
force_fetch: bool, optional
Force update even before a cached item has expired, defaults to False
recursive: bool, optional
If this should retrieve the parameter values recursively or not
sdk_options: dict, optional
Arguments that will be passed directly to the underlying API call
Raises
------
GetParameterError
When the parameter provider fails to retrieve parameter values for
a given path.
TransformParameterError
When the parameter provider fails to transform a parameter value.
"""
# If max_age is not set, resolve it from the environment variable, defaulting to DEFAULT_MAX_AGE_SECS
max_age = resolve_max_age(env=os.getenv(constants.PARAMETERS_MAX_AGE_ENV, DEFAULT_MAX_AGE_SECS), choice=max_age)
# If decrypt is not set, resolve it from the environment variable, defaulting to False
decrypt = resolve_truthy_env_var_choice(
env=os.getenv(constants.PARAMETERS_SSM_DECRYPT_ENV, "false"),
choice=decrypt,
)
sdk_options["decrypt"] = decrypt
sdk_options["recursive"] = recursive
return super().get_multiple(path, max_age, transform, raise_on_transform_error, force_fetch, **sdk_options)
# We break Liskov substitution principle due to differences in signatures of this method and superclass get method
# We ignore mypy error, as changes to the signature here or in a superclass is a breaking change to users
def get( # type: ignore[override]
self,
name: str,
max_age: int | None = None,
transform: TransformOptions = None,
decrypt: bool | None = None,
force_fetch: bool = False,
**sdk_options,
) -> str | bytes | dict | None:
"""
Retrieve a parameter value or return the cached value
Parameters
----------
name: str
Parameter name
max_age: int, optional
Maximum age of the cached value
transform: str
Optional transformation of the parameter value. Supported values
are "json" for JSON strings and "binary" for base 64 encoded
values.
decrypt: bool, optional
If the parameter value should be decrypted
force_fetch: bool, optional
Force update even before a cached item has expired, defaults to False
sdk_options: dict, optional
Arguments that will be passed directly to the underlying API call
Raises
------
GetParameterError
When the parameter provider fails to retrieve a parameter value for
a given name.
TransformParameterError
When the parameter provider fails to transform a parameter value.
"""
# If max_age is not set, resolve it from the environment variable, defaulting to DEFAULT_MAX_AGE_SECS
max_age = resolve_max_age(env=os.getenv(constants.PARAMETERS_MAX_AGE_ENV, DEFAULT_MAX_AGE_SECS), choice=max_age)
# If decrypt is not set, resolve it from the environment variable, defaulting to False
decrypt = resolve_truthy_env_var_choice(
env=os.getenv(constants.PARAMETERS_SSM_DECRYPT_ENV, "false"),
choice=decrypt,
)
# Add to `decrypt` sdk_options to we can have an explicit option for this
sdk_options["decrypt"] = decrypt
return super().get(name, max_age, transform, force_fetch, **sdk_options)
@overload
def set(
self,
name: str,
value: list[str],
*,
overwrite: bool = False,
description: str = "",
parameter_type: Literal["StringList"] = "StringList",
tier: Literal["Standard", "Advanced", "Intelligent-Tiering"] = "Standard",
kms_key_id: str | None = "None",
**sdk_options,
): ...
@overload
def set(
self,
name: str,
value: str,
*,
overwrite: bool = False,
description: str = "",
parameter_type: Literal["SecureString"] = "SecureString",
tier: Literal["Standard", "Advanced", "Intelligent-Tiering"] = "Standard",
kms_key_id: str,
**sdk_options,
): ...
@overload
def set(
self,
name: str,
value: str,
*,
overwrite: bool = False,
description: str = "",
parameter_type: Literal["String"] = "String",
tier: Literal["Standard", "Advanced", "Intelligent-Tiering"] = "Standard",
kms_key_id: str | None = None,
**sdk_options,
): ...
def set(
self,
name: str,
value: str | list[str],
*,
overwrite: bool = False,
description: str = "",
parameter_type: SSM_PARAMETER_TYPES = "String",
tier: SSM_PARAMETER_TIER = "Standard",
kms_key_id: str | None = None,
**sdk_options,
) -> PutParameterResultTypeDef:
"""
Sets a parameter in AWS Systems Manager Parameter Store.
Parameters
----------
name: str
The fully qualified name includes the complete hierarchy of the parameter name and name.
value: str
The parameter value
overwrite: bool, optional
If the parameter value should be overwritten, False by default
description: str, optional
The description of the parameter
parameter_type: str, optional
Type of the parameter. Allowed values are String, StringList, and SecureString
tier: str, optional
The parameter tier to use. Allowed values are Standard, Advanced, and Intelligent-Tiering
kms_key_id: str, optional
The KMS key id to use to encrypt the parameter
sdk_options: dict, optional
Dictionary of options that will be passed to the Parameter Store get_parameter API call
Raises
------
SetParameterError
When the parameter provider fails to retrieve a parameter value for
a given name.
URLs:
-------
https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ssm/client/put_parameter.html
Example
-------
**Sets a parameter value from Systems Manager Parameter Store**
>>> from aws_lambda_powertools.utilities import parameters
>>>
>>> response = parameters.set_parameter(name="/my/example/parameter", value="More Powertools")
>>>
>>> print(response)
123
Returns
-------
PutParameterResultTypeDef
The dict returned by boto3.
"""
opts = {
"Name": name,
"Value": value,
"Overwrite": overwrite,
"Type": parameter_type,
"Tier": tier,
"Description": description,
**sdk_options,
}
if kms_key_id:
opts["KeyId"] = kms_key_id
try:
return self.client.put_parameter(**opts)
except Exception as exc:
raise SetParameterError(f"Error setting parameter - {str(exc)}") from exc
def _get(self, name: str, decrypt: bool = False, **sdk_options) -> str:
"""
Retrieve a parameter value from AWS Systems Manager Parameter Store
Parameters
----------
name: str
Parameter name
decrypt: bool, optional
If the parameter value should be decrypted
sdk_options: dict, optional
Dictionary of options that will be passed to the Parameter Store get_parameter API call
"""
# Explicit arguments will take precedence over keyword arguments
sdk_options["Name"] = name
sdk_options["WithDecryption"] = decrypt
return self.client.get_parameter(**sdk_options)["Parameter"]["Value"]
def _get_multiple(
self,
path: str,
decrypt: bool | None = None,
recursive: bool = False,
**sdk_options,
) -> dict[str, str]:
"""
Retrieve multiple parameter values from AWS Systems Manager Parameter Store
Parameters
----------
path: str
Path to retrieve the parameters
decrypt: bool, optional
If the parameter values should be decrypted
recursive: bool, optional
If this should retrieve the parameter values recursively or not
sdk_options: dict, optional
Dictionary of options that will be passed to the Parameter Store get_parameters_by_path API call
"""
# Explicit arguments will take precedence over keyword arguments
sdk_options["Path"] = path
sdk_options["WithDecryption"] = decrypt
sdk_options["Recursive"] = recursive
parameters = {}
for page in self.client.get_paginator("get_parameters_by_path").paginate(**sdk_options):
for parameter in page.get("Parameters", []):
# Standardize the parameter name
# The parameter name returned by SSM will contain the full path.
# However, for readability, we should return only the part after
# the path.
name = parameter["Name"]
if name.startswith(path):
name = name[len(path) :]
name = name.lstrip("/")
parameters[name] = parameter["Value"]
return parameters
# NOTE: When bandwidth permits, allocate a week to refactor to lower cognitive load
def get_parameters_by_name(
self,
parameters: dict[str, dict],
transform: TransformOptions = None,
decrypt: bool | None = None,
max_age: int | None = None,
raise_on_error: bool = True,
) -> dict[str, str] | dict[str, bytes] | dict[str, dict]:
"""
Retrieve multiple parameter values by name from SSM or cache.
Raise_on_error decides on error handling strategy:
- A) Default to fail-fast. Raises GetParameterError upon any error
- B) Gracefully aggregate all parameters that failed under "_errors" key
It transparently uses GetParameter and/or GetParameters depending on decryption requirements.
┌────────────────────────┐
┌───▶ Decrypt entire batch │─────┐
│ └────────────────────────┘ │ ┌────────────────────┐
│ ├─────▶ GetParameters API │
┌──────────────────┐ │ ┌────────────────────────┐ │ └────────────────────┘
│ Split batch │─── ┼──▶│ No decryption required │─────┘
└──────────────────┘ │ └────────────────────────┘
│ ┌────────────────────┐
│ ┌────────────────────────┐ │ GetParameter API │
└──▶│Decrypt some but not all│───────────▶────────────────────┤
└────────────────────────┘ │ GetParameters API │
└────────────────────┘
Parameters
----------
parameters: dict[str, dict]
List of parameter names, and any optional overrides
transform: str, optional
Transforms the content from a JSON object ('json') or base64 binary string ('binary')
decrypt: bool, optional
If the parameter values should be decrypted
max_age: int, optional
Maximum age of the cached value
raise_on_error: bool
Whether to fail-fast or fail gracefully by including "_errors" key in the response, by default True
Raises
------
GetParameterError
When the parameter provider fails to retrieve a parameter value for a given name.
When "_errors" reserved key is in parameters to be fetched from SSM.
"""
# If max_age is not set, resolve it from the environment variable, defaulting to DEFAULT_MAX_AGE_SECS
max_age = resolve_max_age(env=os.getenv(constants.PARAMETERS_MAX_AGE_ENV, DEFAULT_MAX_AGE_SECS), choice=max_age)
# If decrypt is not set, resolve it from the environment variable, defaulting to False
decrypt = resolve_truthy_env_var_choice(
env=os.getenv(constants.PARAMETERS_SSM_DECRYPT_ENV, "false"),
choice=decrypt,
)
# Init potential batch/decrypt batch responses and errors
batch_ret: dict[str, Any] = {}
decrypt_ret: dict[str, Any] = {}
batch_err: list[str] = []
decrypt_err: list[str] = []
response: dict[str, Any] = {}
# NOTE: We fail early to avoid unintended graceful errors being replaced with their '_errors' param values
self._raise_if_errors_key_is_present(parameters, self._ERRORS_KEY, raise_on_error)
batch_params, decrypt_params = self._split_batch_and_decrypt_parameters(parameters, transform, max_age, decrypt)
# NOTE: We need to find out whether all parameters must be decrypted or not to know which API to use
## Logic:
##
## GetParameters API -> When decrypt is used for all parameters in the the batch
## GetParameter API -> When decrypt is used for one or more in the batch
if len(decrypt_params) != len(parameters):
decrypt_ret, decrypt_err = self._get_parameters_by_name_with_decrypt_option(decrypt_params, raise_on_error)
batch_ret, batch_err = self._get_parameters_batch_by_name(batch_params, raise_on_error, decrypt=False)
else:
batch_ret, batch_err = self._get_parameters_batch_by_name(decrypt_params, raise_on_error, decrypt=True)
# Fail-fast disabled, let's aggregate errors under "_errors" key so they can handle gracefully
if not raise_on_error:
response[self._ERRORS_KEY] = [*decrypt_err, *batch_err]
return {**response, **batch_ret, **decrypt_ret}
def _get_parameters_by_name_with_decrypt_option(
self,
batch: dict[str, dict],
raise_on_error: bool,
) -> tuple[dict, list]:
response: dict[str, Any] = {}
errors: list[str] = []
# Decided for single-thread as it outperforms in 128M and 1G + reduce timeout risk
# see: https://github.com/aws-powertools/powertools-lambda-python/issues/1040#issuecomment-1299954613
for parameter, options in batch.items():
try:
response[parameter] = self.get(parameter, options["max_age"], options["transform"], options["decrypt"])
except GetParameterError:
if raise_on_error:
raise
errors.append(parameter)
continue
return response, errors
def _get_parameters_batch_by_name(
self,
batch: dict[str, dict],
raise_on_error: bool = True,
decrypt: bool = False,
) -> tuple[dict, list]:
"""Slice batch and fetch parameters using GetParameters by max permitted"""
errors: list[str] = []
# Fetch each possible batch param from cache and return if entire batch is cached
cached_params = self._get_parameters_by_name_from_cache(batch)
if len(cached_params) == len(batch):
return cached_params, errors
# Slice batch by max permitted GetParameters call
batch_ret, errors = self._get_parameters_by_name_in_chunks(batch, cached_params, raise_on_error, decrypt)
return {**cached_params, **batch_ret}, errors
def _get_parameters_by_name_from_cache(self, batch: dict[str, dict]) -> dict[str, Any]:
"""Fetch each parameter from batch that hasn't been expired"""
cache = {}
for name, options in batch.items():
cache_key = (name, options["transform"])
if self.has_not_expired_in_cache(cache_key):
cache[name] = self.store[cache_key].value
return cache
def _get_parameters_by_name_in_chunks(
self,
batch: dict[str, dict],
cache: dict[str, Any],
raise_on_error: bool,
decrypt: bool = False,
) -> tuple[dict, list]:
"""Take out differences from cache and batch, slice it and fetch from SSM"""
response: dict[str, Any] = {}
errors: list[str] = []
diff = {key: value for key, value in batch.items() if key not in cache}
for chunk in slice_dictionary(data=diff, chunk_size=self._MAX_GET_PARAMETERS_ITEM):
response, possible_errors = self._get_parameters_by_name(
parameters=chunk,
raise_on_error=raise_on_error,
decrypt=decrypt,
)
response.update(response)
errors.extend(possible_errors)
return response, errors
def _get_parameters_by_name(
self,
parameters: dict[str, dict],
raise_on_error: bool = True,
decrypt: bool = False,
) -> tuple[dict[str, Any], list[str]]:
"""Use SSM GetParameters to fetch parameters, hydrate cache, and handle partial failure
Parameters
----------
parameters : dict[str, dict]
Parameters to fetch
raise_on_error : bool, optional
Whether to fail-fast or fail gracefully by including "_errors" key in the response, by default True
Returns
-------
dict[str, Any]
Retrieved parameters as key names and their values
Raises
------
GetParameterError
When one or more parameters failed on fetching, and raise_on_error is enabled
"""
ret: dict[str, Any] = {}
batch_errors: list[str] = []
parameter_names = list(parameters.keys())
# All params in the batch must be decrypted
# we return early if we hit an unrecoverable exception like InvalidKeyId/InternalServerError
# everything else should technically be recoverable as GetParameters is non-atomic
try:
if decrypt:
response = self.client.get_parameters(Names=parameter_names, WithDecryption=True)
else:
response = self.client.get_parameters(Names=parameter_names)
except (self.client.exceptions.InvalidKeyId, self.client.exceptions.InternalServerError):
return ret, parameter_names
batch_errors = self._handle_any_invalid_get_parameter_errors(response, raise_on_error)
transformed_params = self._transform_and_cache_get_parameters_response(response, parameters, raise_on_error)
return transformed_params, batch_errors
def _transform_and_cache_get_parameters_response(
self,
api_response: GetParametersResultTypeDef,
parameters: dict[str, Any],
raise_on_error: bool = True,
) -> dict[str, Any]:
response: dict[str, Any] = {}
for parameter in api_response["Parameters"]:
name = parameter["Name"]
value = parameter["Value"]
options = parameters[name]
transform = options.get("transform")
# NOTE: If transform is set, we do it before caching to reduce number of operations
if transform:
value = transform_value(name, value, transform, raise_on_error) # type: ignore
_cache_key = (name, options["transform"])
self.add_to_cache(key=_cache_key, value=value, max_age=options["max_age"])
response[name] = value
return response
@staticmethod
def _handle_any_invalid_get_parameter_errors(
api_response: GetParametersResultTypeDef,
raise_on_error: bool = True,
) -> list[str]:
"""GetParameters is non-atomic. Failures don't always reflect in exceptions so we need to collect."""
failed_parameters = api_response["InvalidParameters"]
if failed_parameters:
if raise_on_error:
raise GetParameterError(f"Failed to fetch parameters: {failed_parameters}")
return failed_parameters
return []
@staticmethod
def _split_batch_and_decrypt_parameters(
parameters: dict[str, dict],
transform: TransformOptions,
max_age: int,
decrypt: bool,
) -> tuple[dict[str, dict], dict[str, dict]]:
"""Split parameters that can be fetched by GetParameters vs GetParameter
Parameters
----------
parameters : dict[str, dict]
Parameters containing names as key and optional config override as value
transform : TransformOptions
Transform configuration
max_age : int
How long to cache a parameter for
decrypt : bool
Whether to use KMS to decrypt a parameter
Returns
-------
tuple[dict[str, dict], dict[str, dict]]
GetParameters and GetParameter parameters dict along with their overrides/globals merged
"""
batch_parameters: dict[str, dict] = {}
decrypt_parameters: dict[str, Any] = {}
for parameter, options in parameters.items():
# NOTE: TypeDict later
_overrides = options or {}
_overrides["transform"] = _overrides.get("transform") or transform
# These values can be falsy (False, 0)
if "decrypt" not in _overrides:
_overrides["decrypt"] = decrypt
if "max_age" not in _overrides:
_overrides["max_age"] = max_age
# NOTE: Split parameters who have decrypt OR have it global
if _overrides["decrypt"]:
decrypt_parameters[parameter] = _overrides
else:
batch_parameters[parameter] = _overrides
return batch_parameters, decrypt_parameters
@staticmethod
def _raise_if_errors_key_is_present(parameters: dict, reserved_parameter: str, raise_on_error: bool):
"""Raise GetParameterError if fail-fast is disabled and '_errors' key is in parameters batch"""
if not raise_on_error and reserved_parameter in parameters:
raise GetParameterError(
f"You cannot fetch a parameter named '{reserved_parameter}' in graceful error mode.",
)
@overload
def get_parameter(
name: str,
transform: None = None,
decrypt: bool | None = None,
force_fetch: bool = False,
max_age: int | None = None,
**sdk_options,
) -> str: ...
@overload
def get_parameter(
name: str,
transform: Literal["json"],
decrypt: bool | None = None,
force_fetch: bool = False,
max_age: int | None = None,
**sdk_options,
) -> dict: ...
@overload
def get_parameter(
name: str,
transform: Literal["binary"],
decrypt: bool | None = None,
force_fetch: bool = False,
max_age: int | None = None,
**sdk_options,
) -> str | bytes | dict: ...
@overload
def get_parameter(
name: str,
transform: Literal["auto"],
decrypt: bool | None = None,
force_fetch: bool = False,
max_age: int | None = None,
**sdk_options,
) -> bytes: ...
def get_parameter(
name: str,
transform: TransformOptions = None,
decrypt: bool | None = None,
force_fetch: bool = False,
max_age: int | None = None,
**sdk_options,
) -> str | bytes | dict:
"""
Retrieve a parameter value from AWS Systems Manager (SSM) Parameter Store
Parameters
----------
name: str
Name of the parameter
transform: str, optional
Transforms the content from a JSON object ('json') or base64 binary string ('binary')
decrypt: bool, optional
If the parameter values should be decrypted
force_fetch: bool, optional
Force update even before a cached item has expired, defaults to False
max_age: int, optional
Maximum age of the cached value
sdk_options: dict, optional
Dictionary of options that will be passed to the Parameter Store get_parameter API call
Raises
------
GetParameterError
When the parameter provider fails to retrieve a parameter value for
a given name.
TransformParameterError
When the parameter provider fails to transform a parameter value.
Example
-------
**Retrieves a parameter value from Systems Manager Parameter Store**
>>> from aws_lambda_powertools.utilities.parameters import get_parameter
>>>
>>> value = get_parameter("/my/parameter")
>>>
>>> print(value)
My parameter value
**Retrieves a parameter value and decodes it using a Base64 decoder**
>>> from aws_lambda_powertools.utilities.parameters import get_parameter
>>>
>>> value = get_parameter("/my/parameter", transform='binary')
>>>
>>> print(value)
My parameter value
"""
# Only create the provider if this function is called at least once
if "ssm" not in DEFAULT_PROVIDERS:
DEFAULT_PROVIDERS["ssm"] = SSMProvider()
# If max_age is not set, resolve it from the environment variable, defaulting to DEFAULT_MAX_AGE_SECS
max_age = resolve_max_age(env=os.getenv(constants.PARAMETERS_MAX_AGE_ENV, DEFAULT_MAX_AGE_SECS), choice=max_age)
# If decrypt is not set, resolve it from the environment variable, defaulting to False
decrypt = resolve_truthy_env_var_choice(
env=os.getenv(constants.PARAMETERS_SSM_DECRYPT_ENV, "false"),
choice=decrypt,
)
return DEFAULT_PROVIDERS["ssm"].get(
name=name,
max_age=max_age,
transform=transform,
force_fetch=force_fetch,
decrypt=decrypt,
**sdk_options,
)
@overload
def get_parameters(
path: str,
transform: None = None,
recursive: bool = True,
decrypt: bool | None = None,
force_fetch: bool = False,
max_age: int | None = None,
raise_on_transform_error: bool = False,
**sdk_options,
) -> dict[str, str]: ...
@overload
def get_parameters(
path: str,
transform: Literal["json"],
recursive: bool = True,
decrypt: bool | None = None,
force_fetch: bool = False,
max_age: int | None = None,
raise_on_transform_error: bool = False,
**sdk_options,
) -> dict[str, dict]: ...
@overload
def get_parameters(
path: str,
transform: Literal["binary"],
recursive: bool = True,
decrypt: bool | None = None,
force_fetch: bool = False,
max_age: int | None = None,
raise_on_transform_error: bool = False,
**sdk_options,
) -> dict[str, bytes]: ...
@overload
def get_parameters(
path: str,
transform: Literal["auto"],
recursive: bool = True,
decrypt: bool | None = None,
force_fetch: bool = False,
max_age: int | None = None,
raise_on_transform_error: bool = False,
**sdk_options,
) -> dict[str, str] | dict[str, bytes] | dict[str, dict]: ...
def get_parameters(
path: str,
transform: TransformOptions = None,
recursive: bool = True,
decrypt: bool | None = None,
force_fetch: bool = False,
max_age: int | None = None,
raise_on_transform_error: bool = False,
**sdk_options,
) -> dict[str, str] | dict[str, bytes] | dict[str, dict]:
"""
Retrieve multiple parameter values from AWS Systems Manager (SSM) Parameter Store
For readability, we strip the path prefix name in the response.
Parameters
----------
path: str
Path to retrieve the parameters
transform: str, optional
Transforms the content from a JSON object ('json') or base64 binary string ('binary')
recursive: bool, optional
If this should retrieve the parameter values recursively or not, defaults to True
decrypt: bool, optional
If the parameter values should be decrypted
force_fetch: bool, optional
Force update even before a cached item has expired, defaults to False
max_age: int, optional
Maximum age of the cached value
raise_on_transform_error: bool, optional
Raises an exception if any transform fails, otherwise this will
return a None value for each transform that failed
sdk_options: dict, optional
Dictionary of options that will be passed to the Parameter Store get_parameters_by_path API call
Raises
------
GetParameterError
When the parameter provider fails to retrieve parameter values for
a given path.
TransformParameterError
When the parameter provider fails to transform a parameter value.
Example
-------
**Retrieves parameter values from Systems Manager Parameter Store**
>>> from aws_lambda_powertools.utilities.parameters import get_parameter
>>>
>>> values = get_parameters("/my/path/prefix")
>>>
>>> for key, value in values.items():
... print(key, value)
config Parameter value (/my/path/prefix/config)
webhook/config Parameter value (/my/path/prefix/webhook/config)
**Retrieves parameter values and decodes them using a Base64 decoder**
>>> from aws_lambda_powertools.utilities.parameters import get_parameter
>>>
>>> values = get_parameters("/my/path/prefix", transform='binary')
"""
# Only create the provider if this function is called at least once
if "ssm" not in DEFAULT_PROVIDERS:
DEFAULT_PROVIDERS["ssm"] = SSMProvider()
# If max_age is not set, resolve it from the environment variable, defaulting to DEFAULT_MAX_AGE_SECS
max_age = resolve_max_age(env=os.getenv(constants.PARAMETERS_MAX_AGE_ENV, DEFAULT_MAX_AGE_SECS), choice=max_age)
# If decrypt is not set, resolve it from the environment variable, defaulting to False
decrypt = resolve_truthy_env_var_choice(
env=os.getenv(constants.PARAMETERS_SSM_DECRYPT_ENV, "false"),
choice=decrypt,
)
return DEFAULT_PROVIDERS["ssm"].get_multiple(
path=path,
max_age=max_age,
transform=transform,
raise_on_transform_error=raise_on_transform_error,
force_fetch=force_fetch,
recursive=recursive,
decrypt=decrypt,
**sdk_options,
)
def set_parameter(
name: str,
value: str,
*, # force keyword arguments
overwrite: bool = False,
description: str = "",
parameter_type: SSM_PARAMETER_TYPES = "String",
tier: SSM_PARAMETER_TIER = "Standard",
kms_key_id: str | None = None,
**sdk_options,
) -> PutParameterResultTypeDef:
"""
Sets a parameter in AWS Systems Manager Parameter Store.
Parameters
----------
name: str
The fully qualified name includes the complete hierarchy of the parameter name and name.
value: str
The parameter value
overwrite: bool, optional
If the parameter value should be overwritten, False by default
description: str, optional
The description of the parameter
parameter_type: str, optional
Type of the parameter. Allowed values are String, StringList, and SecureString
tier: str, optional
The parameter tier to use. Allowed values are Standard, Advanced, and Intelligent-Tiering
kms_key_id: str, optional
The KMS key id to use to encrypt the parameter
sdk_options: dict, optional
Dictionary of options that will be passed to the Parameter Store get_parameter API call
Raises
------
SetParameterError
When attempting to set a parameter fails.
URLs:
-------
https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ssm/client/put_parameter.html
Example
-------
**Sets a parameter value from Systems Manager Parameter Store**
>>> from aws_lambda_powertools.utilities import parameters
>>>
>>> response = parameters.set_parameter(name="/my/example/parameter", value="More Powertools")
>>>
>>> print(response)
123
Returns
-------
PutParameterResultTypeDef
The dict returned by boto3.
"""
# Only create the provider if this function is called at least once
if "ssm" not in DEFAULT_PROVIDERS:
DEFAULT_PROVIDERS["ssm"] = SSMProvider()
return DEFAULT_PROVIDERS["ssm"].set(
name,
value,
parameter_type=parameter_type,
overwrite=overwrite,
tier=tier,
description=description,
kms_key_id=kms_key_id,
**sdk_options,
)
@overload
def get_parameters_by_name(
parameters: dict[str, dict],
transform: None = None,
decrypt: bool | None = None,
max_age: int | None = None,
raise_on_error: bool = True,
) -> dict[str, str]: ...
@overload
def get_parameters_by_name(
parameters: dict[str, dict],
transform: Literal["binary"],
decrypt: bool | None = None,
max_age: int | None = None,
raise_on_error: bool = True,
) -> dict[str, bytes]: ...
@overload
def get_parameters_by_name(
parameters: dict[str, dict],
transform: Literal["json"],
decrypt: bool | None = None,
max_age: int | None = None,
raise_on_error: bool = True,
) -> dict[str, dict[str, Any]]: ...
@overload
def get_parameters_by_name(
parameters: dict[str, dict],
transform: Literal["auto"],
decrypt: bool | None = None,
max_age: int | None = None,
raise_on_error: bool = True,
) -> dict[str, str] | dict[str, dict]: ...
def get_parameters_by_name(
parameters: dict[str, Any],
transform: TransformOptions = None,
decrypt: bool | None = None,
max_age: int | None = None,
raise_on_error: bool = True,
) -> dict[str, str] | dict[str, bytes] | dict[str, dict]:
"""
Retrieve multiple parameter values by name from AWS Systems Manager (SSM) Parameter Store
Parameters
----------
parameters: dict[str, Any]
List of parameter names, and any optional overrides
transform: str, optional
Transforms the content from a JSON object ('json') or base64 binary string ('binary')
decrypt: bool, optional
If the parameter values should be decrypted
max_age: int, optional
Maximum age of the cached value
raise_on_error: bool, optional
Whether to fail-fast or fail gracefully by including "_errors" key in the response, by default True
Example
-------
**Retrieves multiple parameters from distinct paths from Systems Manager Parameter Store**
from aws_lambda_powertools.utilities.parameters import get_parameters_by_name
params = {
"/param": {},
"/json": {"transform": "json"},
"/binary": {"transform": "binary"},
"/no_cache": {"max_age": 0},
"/api_key": {"decrypt": True},
}
values = get_parameters_by_name(parameters=params)
for param_name, value in values.items():
print(f"{param_name}: {value}")
# "/param": value
# "/json": value
# "/binary": value
# "/no_cache": value
# "/api_key": value
Raises
------
GetParameterError
When the parameter provider fails to retrieve a parameter value for
a given name.
"""
# NOTE: Decided against using multi-thread due to single-thread outperforming in 128M and 1G + timeout risk
# see: https://github.com/aws-powertools/powertools-lambda-python/issues/1040#issuecomment-1299954613
# If max_age is not set, resolve it from the environment variable, defaulting to DEFAULT_MAX_AGE_SECS
max_age = resolve_max_age(env=os.getenv(constants.PARAMETERS_MAX_AGE_ENV, DEFAULT_MAX_AGE_SECS), choice=max_age)
# If decrypt is not set, resolve it from the environment variable, defaulting to False
decrypt = resolve_truthy_env_var_choice(
env=os.getenv(constants.PARAMETERS_SSM_DECRYPT_ENV, "false"),
choice=decrypt,
)
# Only create the provider if this function is called at least once
if "ssm" not in DEFAULT_PROVIDERS:
DEFAULT_PROVIDERS["ssm"] = SSMProvider()
return DEFAULT_PROVIDERS["ssm"].get_parameters_by_name(
parameters=parameters,
max_age=max_age,
transform=transform,
decrypt=decrypt,
raise_on_error=raise_on_error,
)
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