Configurable log handler

[xoxys]

Instead of a hard-coded file handler for logging, it would be helpful to make it configurable. At least an optional stream handler might make sense in a container environment.

[glpatcern]

I can see the advantage in a fully (e.g. helm-based) containerized environment, however so far we have run this service in a hybrid environment, where log files are piped through other non-containerized services as well as "traditionally" rotated. Of course having both options would be good.