Using Host network

Hello,

I am trying to reduce an image based on Debian but I have some issues with the Network. The image I am working on is this one: https://hub.docker.com/r/torpi/roon-core

For some reasons, Roon-Server must run on Host network. Clients and endpoints will not connect otherwise so I cannot run scenarios for the reduction and end with a non-working image.

My naive approch was to set the network like we do with docker run or docker-compose:

./docker-slim build --network="host" imageid

Unfortunately this does not work and the error is not really helpful to me. I was not able to find more information on github or leveraging Google.

Is that a limitation of the tool or am I doing something wrong?
Any help would be appreciated!

docker-slim[build]: state=started docker-slim[build]: info=params target=fc706cdecd24 continue.mode=enter docker-slim[build]: state=inspecting.image docker-slim[build]: info=image id=sha256:fc706cdecd247e3e1d9af9fb40cfe270b2e6509706268895abbeb94dea89c77b size.bytes=562111628 size.human=562 MB docker-slim[build]: info=image.layers index=0 name='torpi/roon-core' tags='latest' docker-slim[build]: state=inspecting.container docker-slim[build]: info=container status=created id=eaa479b8ec017f7d68479ecb4bb2e6b8c25134d1a1e110caafc85100d3949d3b time="2019-06-19T18:32:55Z" level=fatal msg="docker-slim: failure" error="docker-slim: error => missing comms ports" stack="goroutine 1 [running]: runtime/debug.Stack(0x17a1, 0xc000126480, 0x3) /usr/local/Cellar/go/1.11.1/libexec/src/runtime/debug/stack.go:24 +0xa7 github.com/docker-slim/docker-slim/pkg/utils/errutils.FailWhen(0xc00017e001, 0x90ce57, 0x29) /Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/pkg/utils/errutils/errutils.go:30 +0x53 github.com/docker-slim/docker-slim/internal/app/master/inspectors/container.(*Inspector).RunContainer(0xc000088a80, 0xc000127048, 0x1) /Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/internal/app/master/inspectors/container/container_inspector.go:324 +0x13df github.com/docker-slim/docker-slim/internal/app/master/commands.OnBuild(0x868101, 0x0, 0x0, 0x0, 0xc000206180, 0x17, 0xc00007a150, 0x7ffc2810a787, 0xc, 0x0, ...) /Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/internal/app/master/commands/build.go:157 +0xf7f github.com/docker-slim/docker-slim/internal/app/master.init.0.func6(0xc000174140, 0x0, 0xc000174140) /Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/internal/app/master/cli.go:606 +0x1209 github.com/docker-slim/docker-slim/vendor/github.com/codegangsta/cli.HandleAction(0x857400, 0x91a070, 0xc000174140, 0xc00005a000, 0x0) /Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/vendor/github.com/codegangsta/cli/app.go:485 +0xc8 github.com/docker-slim/docker-slim/vendor/github.com/codegangsta/cli.Command.Run(0x8fabe6, 0x5, 0x0, 0x0, 0xc0000995f0, 0x1, 0x1, 0x912fad, 0x3e, 0x0, ...) /Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/vendor/github.com/codegangsta/cli/command.go:207 +0x991 github.com/docker-slim/docker-slim/vendor/github.com/codegangsta/cli.(*App).Run(0xc0000aeb60, 0xc00008a000, 0x4, 0x4, 0x0, 0x0) /Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/vendor/github.com/codegangsta/cli/app.go:250 +0x6ea github.com/docker-slim/docker-slim/internal/app/master.runCli() /Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/internal/app/master/cli.go:906 +0x55 github.com/docker-slim/docker-slim/internal/app/master.Run() /Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/internal/app/master/app.go:6 +0x25 main.main() /Users/q/docker-slim/docker-slim/_gopath/src/github.com/docker-slim/docker-slim/cmd/docker-slim/main.go:8 +0x20 " version="linux|Transformer|1.25.0|4d304c9adf0d2315ec8d4ca197070f040500cc68|2019-04-25_01:57:04AM (go1.11.1)"

Reproduce the reported command with --network="host" and start at internal/app/master/inspectors/container/container_inspector.go:324, where the missing-comms-ports error is raised, then trace the call from internal/app/master/commands/build.go:157. Done means determining whether host networking is supported and providing working behavior or an actionable explanation for this case.