Serverless container yaml not extracting ssm variables

Serverless Framework
1

I am trying to get secret from secret manager. The current documentation for env vars for the serverless container config shows to do the following which doesn’t make sense.

DATABASE_ARN: ${env:DATABASE_ARN} # Example, using Serverless Framework Variables to resolve a value from AWS Secrets Manager.  
DATABASE_URL: ${aws:ssm:/path/to/param} # Example, using Serverless Framework Variables to resolve a value from AWS Systems Manager Parameter Store.

Now I have a secret stored where it is a key value store the key is just “key” and I want the env var to be the stored string.

If I don’t try to reference with “.key” I get an object which throws an error

 - containers.service.environment.API_KEY : Expected string, received object 
 Input:
    API_KEY : ${aws:ssm:/aws/reference/secretsmanager/api-key}

If I try to use “.key” there is no value found

variable at 'containers.service.environment.API_KEY'. No value is available for this variable, and no default value was provided.
Input
    API_KEY : ${aws:ssm:/aws/reference/secretsmanager/api-key.key}

With lambdas I have done the following to get this to work. I relied on the custom resolver which doesn’t exist for containers.

Below is what works for me in lambda

environment:
   API_KEY: ${self:custom.api_key.key}
custom:
  api_key: ${ssm:/aws/reference/secretsmanager/api-key}

Is there a way to do this for container yamls?

2

${aws:ssm... is not correct. Try ${ssm:/...}

Reference: Serverless Framework - Variables - AWS SSM & Secrets Manager