I'm learning my way around swarm mode at this point, and normally when wanting to copy files to and from a container in non-swarm mode I would just do something like the following, to copy a file to a container named "swag":
docker cp "C:\Sites\somefile.conf" swag:/config/nginx/proxy-confs
But in swarm mode, the container names are appended with .<some long random hash each time one is started>, i.e. stackname_swag.d98s7fds89f98d7sf.
Using "swag" as the container name in that case fails, as does using "stackname_swag". I am assuming that one could copy the entire container name including the hash (haven't tried it), and I know that I can copy the container ID and use that instead of the container name, but it seems like there should be a method where you don't have to do a look-up first to copy an ID or a name + hash, and just use a general "name" of a container/service ...
Is there such a method?
I don't believe there is another way to do this in swarm, the process you described would be the way to go. That being said, by the looks of it you are trying to copy in a config file which if you are doing this just for testing/dev it's fine, but if looking for something that you can use in prod then you should look at other ways to get you config into the container. Depending on what you need you can either use docker configs, you can create a named volume, you could can use a bind mount, you can even use a custom image that already has your config in it.