CloudFormation parameters use by YAML format

cfnyaml.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import argparse
import json
try:
    import boto3
    import yaml
except ImportError:
    print '*******************************'
    print 'ERROR : Please install boto3 and PyYAML. Please exec following commad.'
    print 'pip install boto3 PyYAML'
    print '*******************************'
    import sys
    sys.exit(1)


def parse_args():
    parser = argparse.ArgumentParser()
    subparser = parser.add_subparsers()

    parser_gen = subparser.add_parser('generate-parameters')
    parser_gen.add_argument('--template-file', dest='template_file', required=True)
    parser_gen.add_argument('--parameters-file', dest='parameters_file', required=True)
    parser_gen.set_defaults(func=generate_parameters)
    parser_gen2 = subparser.add_parser('g')
    parser_gen2.add_argument('--template-file', dest='template_file', required=True)
    parser_gen2.add_argument('--parameters-file', dest='parameters_file', required=True)
    parser_gen2.set_defaults(func=generate_parameters)

    parser_create = subparser.add_parser('create-stack')
    parser_create.add_argument('--stack-name', dest='stack_name', required=True)
    parser_create.add_argument('--template-file', dest='template_file', required=True)
    parser_create.add_argument('--parameters-file', dest='parameters_file', required=True)
    parser_create.add_argument('--profile', dest='profile', required=False)
    parser_create.set_defaults(func=create_stack)
    parser_create2 = subparser.add_parser('c')
    parser_create2.add_argument('--stack-name', dest='stack_name', required=True)
    parser_create2.add_argument('--template-file', dest='template_file', required=True)
    parser_create2.add_argument('--parameters-file', dest='parameters_file', required=False)
    parser_create2.add_argument('--profile', dest='profile', required=False)
    parser_create2.set_defaults(func=create_stack)

    return parser.parse_args()

def _write_yaml_file(file_path, params):
    with open(file_path, "w") as f:
        for name, data in params.items():
            default = None
            for key, val in data.items():
                if isinstance(val, (list, dict)):
                    val = json.dumps(val)
                if key == 'Default':
                    default = val
                f.writelines("### %s: %s\n" % (key, str(val)))
            f.writelines(name + ": %s\n" % (default if default else ''))
            f.writelines("\n")

def _read_yaml_file(file_path):
    with open(file_path) as f:
        return yaml.load(f.read())

def _read_json_file(file_path):
    with open(file_path) as f:
        return json.load(f)

def _create_parameters_format(params):
    cfn_params = []
    for key, value in params.items():
        cfn_params.append({'ParameterKey': key, 'ParameterValue': value})
    return cfn_params

def generate_parameters(args):
    body = _read_json_file(args.template_file)
    params = body['Parameters']
    _write_yaml_file(args.parameters_file, params)

def create_stack(args):
    template = json.dumps(_read_json_file(args.template_file))
    params = None
    if args.parameters_file:
        params = _create_parameters_format(_read_yaml_file(args.parameters_file))
    session = boto3.session.Session(profile_name=args.profile)
    session.client('cloudformation').create_stack(
        StackName=args.stack_name,
        TemplateBody=template,
        Parameters=params,
        Capabilities=[ 'CAPABILITY_IAM' ],
    )

def main():
    args = parse_args()
    args.func(args)

if __name__ == "__main__":
    main()