How to emulate AWS Parameter Store on local computer for lambda function development?

Question

I'm using Serverless framework and NodeJS to develop my AWS Lambda function. So far, I have used .env file to store my secrets. So, I can get access to them in serverless.yml like this

provider:
  ...
  environment:
    DB_HOST: ${env:DB_HOST}
    DB_PORT: ${env:DB_PORT}

But now I need to use AWS Parameter Store instead of .env file. I have tried to find information about how to emulate it on my local machine, but I couldn't.

I think, I have to use one serverless config file on local and staging. I need a way to select somehow env values either from .env file (if it's local machine) or from Parameter Store (if it's AWS Lambda). Is there any way how to do it? Thanks!

Answer 1

It should work like this: within your serverless.yml you can reference .env parameters with ${env:keyname} and AWS Parameters using the ${param:keyname} syntax.

If you need to support both of them you just need to write ${env:keyname, param:keyname}.

Here's an example:

provider:
  ...
  environment:
    ALLOWED_ORIGINS: ${env:ALLOWED_ORIGINS, param:ALLOWED_ORIGINS}
    AUTHORIZER_ARN: ${env:AUTHORIZER_ARN, param:AUTHORIZER_ARN}
    MONGODB_URL: ${env:MONGODB_URL, param:MONGODB_URL}