Cache multiple AWS Parameter Store values in an AWS Lambda?

Programming
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1

Rewritten Issue

I am trying to limit the number of calls to AWS Parameter Store in my AWS Lambda and am using a global variable to cache a Parameter Store value on the first call. However, if I want to cache multiple Parameter Store values, I must create multiple global variables and if not [INSERT_GLOBAL_VARIABLE] checks. I have attempted to solve this issue by creating a ParameterUtil class to cache the AWS Boto client as an instance variable and then get_parameter using the cached Boto client. I am unsure if this solves the issue and would like to know if caching the Boto client will result in only one call per parameter to the Parameter Store when get_parameter is called.

import os

import boto3


redis_password = None

def get_redis_password():
    global redis_password
    if not redis_password:
        client = boto3.client("ssm")
        redis_password = client.get_parameter(
            Name=f"{os.environ["ENV"]}.redis-cache.password",
            WithDecryption=True
        )
    return redis_password["Parameter"]["Value"]

def lambda_handler(event, context):
    get_redis_password()

parameter_util.py

import os
import boto3


class ParameterUtil:
    def __init__(self):
        self.boto_client = boto3.client("ssm")

    def get_parameter(self, parameter_path):
        response = self.boto_client.get_parameter(
            Name=f"{os.environ['ENV']}.{parameter_path}", WithDecryption=True
        )

        return response["Parameter"]["Value"]

main.py

import os

import boto3

from parameter_util import ParameterUtil


redis_password = None

def lambda_handler(event, context):
    param_util = ParameterUtil()
    param_util.get_parameter(".redis-cache.password")
    param_util.get_parameter(".another.parameter.store.key")
2

Yes, caching the Boto client in the ParameterUtil class will result in only one call per parameter to the Parameter Store when get_parameter is called.