Access AWS Secrets Manager from AWS Elastic Beanstalk

I finally figured out how to connect my Incident Response Java application running in AWS Elastic Beanstalk with its associated secret in AWS Secrets Manager. As always, the solution is obvious once it is known. What is not so obvious to me as I write this, is how many of previous "solutions" were correct but the "system" had not yet become "eventually consistent?" Moreover, the current solution is very specific and that seems wrong. Nevertheless, here are the solution's parts.

Assume you have created an AWS Secrets Manager called S1 and an AWS Elastic Beanstalk called A1. What you now need to do is to

1. Create an IAM Policy called P1 that enables access to S1.
2. Attach policy P1 to the role aws-elasticbeanstalk-service-role.
3. Attach policy P1 to the role aws-elasticbeanstalk-ec2-role.

When creating policy P1 give it all Secrets Manager's List and Read actions. I am sure some can be skipped and so you and I should go back and remove unneeded actions. You will also need to limit the actions to only the S1 resource, aka its ARN.

Once this is done, restart your application A1 and it will now have access the S1 secret and its keys and their values.

Since Incident Response needs to store its data in AWS SimpleDB, I extended the S1 policy to include all access to any AWS SimpleDB domain, but this did not work. I had to restrict access to a specific domain's ARN. What bothers me about this is that I have now specified the specific domain in both P1 and as a secret S1 key "aws.simpledb.domain" value. Perhaps there is a way I can read the domain from the policy; an exploration for another day.