Get all env variables for all AWS Lamda functions in a CloudFormation/SAM stack

get-vars.py

#! /usr/bin/env python

# Use at your own risk and reward.
# requires boto3 to be installed
# example `./get-vars.py MyStack > vars.json`

import sys, json
import boto3

if len(sys.argv) == 1:
   print('CloudFormation stack required')
   sys.exit()

cloudformation_client = boto3.client('cloudformation')
lambda_client = boto3.client('lambda')

page = {}

# Grab stack from AWS
try:
    stack_resources = cloudformation_client.list_stack_resources(
        StackName=sys.argv[1]
    )
except Exception as e:
    print(e)
    sys.exit()

# Grab environment vars from each lambda in the stack
for resource in stack_resources['StackResourceSummaries']:
    if(resource['ResourceType']=='AWS::Lambda::Function'):
        lambda_config = lambda_client.get_function_configuration(
            FunctionName=resource['PhysicalResourceId']
        )
        if 'Environment' in lambda_config and 'Variables' in lambda_config['Environment']:
            page[resource['LogicalResourceId']] = lambda_config['Environment']['Variables']

# Print to console
print(json.dumps(page, indent=2))

I use theis script to generate my environment file for using AWS SAM sam local invoke -n environmant-vars.json. As described here: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-using-invoke.html#serverless-sam-cli-using-invoke-environment-file

Hi Eric,

Can you see my fork, I've made some changes for using profile names as a second argument. It will also work if the stack has nested stack. So if you pass the root stack's name it will check if the stack has nested stacks and will pull the information of the nested stack. The link is here

https://gist.github.com/masudur-rahman-niloy/7492fddfa60b54da02afd0f52c63b18c

Good work @masudur-rahman-niloy

Ahhh nice @masudur-rahman-niloy !! Thank you!

I was on a youtube channel. like that tool, congrats!