Every Config Setting can be overridden by convention by creating environment variables in the shell where you run box. This is idea for Docker containers or CI builds were you want to easily set one-off settings and not require an entire JSON file. You set set these as actual environment variables or Java system properties of the CLI. Env vars are loaded AFTER any .cfconfig.json files have been loaded by convention and will override any settings in the JSON. They are not case sensitive.
The var must start with the text cfconfig_ and will be followed by the name of the setting.
For nested settings inside of a struct or array you can use underscores to represent dots. Note the following will error if there is not already a datasource named myDSN in the server.
The overrides are applied using the same mechanism that the cfconfig set command uses, which means you can also pass JSON directly for complex values.