Elastic Beanstalk environment variables

    When you configure Elastic Beanstalk to use environment variables from AWS Secrets Manager, these variables are passed directly to your application but are not typically accessible through the standard shell environment. This is by design for security reasons - environment properties in Elastic Beanstalk are passed only to the application and can't be viewed by connecting to an instance in your environment and running the `env` command.

    For running CLI commands or database migrations that need access to these secrets, you have a few options:

    1. Use the Elastic Beanstalk platform script `get-config` to access environment properties outside of your application code. This script is available on the instance and can be used in deployment scripts or other shell operations. You can find examples of using `get-config` in the elastic-beanstalk-samples GitHub repository.

    2. For database migrations or other operations that need to run in the context of your application, consider implementing these as part of your application's startup process or as an API endpoint that can be triggered externally.

    3. If you need to access these secrets directly in a shell session, you could create a script that uses the AWS CLI to retrieve the secrets directly from AWS Secrets Manager at runtime, rather than relying on the environment variables injected by Elastic Beanstalk.

    4. For more complex deployment scenarios, consider using Elastic Beanstalk's extension capabilities (.ebextensions) to create scripts that run during deployment and can access the necessary secrets.

    Remember that environment variables stored as secrets are handled differently than regular environment variables, especially on certain platforms like Tomcat, where you might need to use specific methods to access them (such as `System.getenv` instead of `System.getProperty` for newer Tomcat platform versions).
  

Sources
Environment variables and other software settings - AWS Elastic Beanstalk
Using Elastic Beanstalk with AWS Secrets Manager and AWS Systems Manager Parameter Store - AWS Elastic Beanstalk