Optional array override

[gfl-chris]

If I have a configuration

addrs_of_service = ["addr_of_service"]

is it possible to replace the contents of the addrs_of_service array with an optional environment variable?

(If and only if ${?ADDR_OF_SERVICE} was defined and had the value "addr2_of_service", then addrs_of_service would become ["addr2_of_service"].)

[2m]

Unfortunately arbitrary config overrides when using -Dconfig.override_with_env_vars=true do not currently work for arrays. However there are discussions going on about how to encode arrays in environment variables and make this work: https://gitter.im/lightbend/config?at=5ce2dfa20ec37966a1a2051f

[mkobit]

Seems related to #369 as well