Before= is used to control service ordering. But is it acceptable (or a good design) to have a
Before= dependency which may not exist? Example use case is an application which expects a reverse proxy to be avaiable but doesn't know if that will be nginx or Apache. In such an example, woukd the following be sane?
# Start the service before either Apache or Nginx, whichever is present Before=nginx.service Before=apache.service