add option to redirect logs with JSON formatting to a file
add option to redirect logs with JSON formatting to a file

rancher/go-machine-service,cloudnautique/go-machine-service,rancherio/go-machine-service,rancherio/go-machine-service,ibuildthecloud/go-machine-service,rancher/go-machine-service,cloudnautique/go-machine-service,ibuildthecloud/go-machine-service