Returns a string that can be `eval`-ed to set secrets as environment variables

set-creds.py

import json
import subprocess

def fetch_value(key):
    return subprocess.check_output(['credstash', '-r', data['region'], '-t', data['table'], 'get', key])

def create_shell_command(variable, credential):
    value = fetch_value(credential)
    return 'export {0}="{1}"'.format(variable, value)

with open('creds.json') as data_file:
    data = json.load(data_file)

values = [create_shell_command(variable, credential) for credential, variable in data['variables'].iteritems()]
print('; '.join(values))