Configuration principles
All the application parameters that are related to the environment and affect the application state must be made configurable. For example, the connection string for a Datomic database that is used by Helping Hands services can be made configurable so that it can be updated externally to point to a specific instance of Datomic in production. Configuration parameters also make it possible to test the application in various environments. For example, if a Datomic connection string is made configurable for Helping Hands services, it can be used to test the services with an in-memory instance of Datomic in local development environments and later changed to point to the production instance of Datomic once they are deployed.
Defining configuration parameters
Applications must support multiple ways of defining the configuration parameters. Using command-line arguments is one of the most common ways of specifying the configuration parameters for the application. Environment...
