Copy AWS Lambda environment variables from source Lambda function to destination Lambda function

copy_lambda_env_vars.py

import argparse
import boto3

"""
Usage: copy_lambda_env_vars.py [-h] [--src-profile-name SRC_PROFILE]
                               [--dst-profile-name DST_PROFILE]
                               src_function dst_function

Utility to copy environment variables from source Lambda function to
destination Lambda function.

positional arguments:
  src_function          Source Lambda function name
  dst_function          Destination Lambda function name

optional arguments:
  -h, --help            show this help message and exit
  --src-profile-name SRC_PROFILE
                        Source Lambda function AWS Profile name
  --dst-profile-name DST_PROFILE
                        Destination Lambda function AWS Profile name
"""

def create_argparser():
    command_description = """
        Utility to copy environment variables from source Lambda function to
        destination Lambda function.
    """

    argparser = argparse.ArgumentParser(description=command_description)

    argparser.add_argument(
        'src_function',
        help='Source Lambda function name')

    argparser.add_argument(
        'dst_function',
        help='Destination Lambda function name')

    argparser.add_argument(
        '--src-profile-name',
        dest='src_profile',
        help='Source Lambda function AWS Profile name')

    argparser.add_argument(
        '--dst-profile-name',
        dest='dst_profile',
        help='Destination Lambda function AWS Profile name')

    return argparser

def copy_env_vars(src_function, dst_function, src_profile, dst_profile):
    if src_profile:
        session = boto3.Session(profile_name=src_profile)
        src_lambda_client = session.client('lambda')
    else:
        src_lambda_client = boto3.client('lambda')

    if dst_profile:
        session = boto3.Session(profile_name=dst_profile)
        dst_lambda_client = session.client('lambda')
    else:
        dst_lambda_client = boto3.client('lambda')

    src_config = src_lambda_client.get_function_configuration(
        FunctionName=src_function)

    dst_lambda_client.update_function_configuration(
      FunctionName=dst_function,
      Environment=src_config['Environment']
    )

def main():
    argparser = create_argparser()
    args = argparser.parse_args()
    copy_env_vars(
        args.src_function, args.dst_function,
        args.src_profile, args.dst_profile)

if __name__ == '__main__':
    main()