POC python class and demo usage to get groups of credentials from parameter store

use_paramater_store_creds.py

# This class retrieves /prefix/* parameters from aws parameter store and lets 
# you either reference them individually or it will put them all into your os environment
# for fetching in familiar ways

import os
import boto3

class AWSParameterClass(object):
    def __init__(self, prefix):
        _project = boto3.client('ssm')
        def get_param_batch(NextToken):
            if NextToken:
                return _project.get_parameters_by_path(
                        Path=prefix,
                        Recursive=True,
                        WithDecryption=True,
                        NextToken=NextToken,
                    )
            else:
                return _project.get_parameters_by_path(
                        Path=prefix,
                        Recursive=True,
                        WithDecryption=True,
                    )
        _pstorage = {}
        NextToken = False
        while True:
            _response = get_param_batch(NextToken)
            for param in _response['Parameters']:
                _pstorage[param['Name'].split('/')[-1]] = param['Value']
            NextToken = _response.get('NextToken',False)
            if not NextToken:
                break
        self.params = _pstorage

    def get(self, name):
        return self.params[name]

    def list_keys(self):
        keys = []
        for key, value in self.params.items():
            print(key)
            keys.append(key)
        return keys

    def put_env(self):
        for key, value in self.params.items():
            os.environ[key] = value

params = AWSParameterClass("/mycompany/webapp/staging")

# You can use the dictionary directly, as further below, or keep an existing env-var based
# workflow by having the class inject the gotten paramters into your envrionment in one fell swoop
params.put_env()

# Parameter store only stores strings, so we end up having to convert them to 
# strings in ie: secrets.yml, and then coercing them into the proper types on this end, ie:

# Strings are pretty easy
EMAIL_HOST = params.get('EMAIL_HOST')
# Booleans
EMAIL_USE_TLS = bool(params.get('EMAIL_USE_TLS'))
# Ints
EMAIL_PORT = int(params.get('EMAIL_PORT'))
# Lists get into interesting erritory with the eval. But if
# this isn't trusted data, we're already screwed
ALLOWED_HOSTS = eval(params.get('ALLOWED_HOSTS'))