If you really need Unix socket support then you will have to use Kotlin Native instead of Kotlin JVM. With some of the Kotlin Native targets (linuxX64, linuxArm32Hfp etc) there is built in access to the POSIX API, which will allow you to use Unix sockets. Please refer to the Non Blocking Echo Server for an example: https://github.com/JetBrains/kotlin-native/tree/master/samples/nonBlockingEchoServer

Does Docker allow communication via Pipes? If so then that would be another option since the JVM does have Pipes support (here is an example: http://tutorials.jenkov.com/java-io/pipes.html ).