tcpproxy.main.kts

#!/usr/bin/env -S kotlinc-jvm -nowarn -script

@file:Repository("https://jcenter.bintray.com")
@file:Repository("https://oss.jfrog.org/oss-snapshot-local")
@file:DependsOn("io.rsocket.kotlin:rsocket-transport-ktor-client-jvm:0.13.0-SNAPSHOT")
@file:DependsOn("io.ktor:ktor-client-cio-jvm:1.5.0")
@file:CompilerOptions("-jvm-target", "1.8")

import io.ktor.client.*
import io.ktor.network.selector.*
import io.ktor.network.sockets.*
import io.rsocket.kotlin.ConnectionAcceptorContext
import io.rsocket.kotlin.RSocket
import io.rsocket.kotlin.core.RSocketConnector
import io.rsocket.kotlin.core.RSocketServer
import io.rsocket.kotlin.logging.LoggingLevel
import io.rsocket.kotlin.logging.PrintLogger
import io.rsocket.kotlin.payload.PayloadMimeType
import io.rsocket.kotlin.transport.ktor.client.rSocket
import io.rsocket.kotlin.transport.ktor.serverTransport
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.runBlocking
import io.ktor.client.engine.cio.CIO as ClientCIO
import io.ktor.client.features.websocket.WebSockets as ClientWebSockets
import io.rsocket.kotlin.transport.ktor.client.RSocketSupport as ClientRSocketSupport

suspend fun connectWebsocket(mimeType: PayloadMimeType, url: String): RSocket {
    val httpClient = HttpClient(ClientCIO) {
        install(ClientWebSockets)
        install(ClientRSocketSupport) {
            connector = RSocketConnector {
                loggerFactory = PrintLogger.withLevel(LoggingLevel.DEBUG)
                connectionConfig {
                    payloadMimeType = mimeType
                }
            }
        }
    }
    return httpClient.rSocket(url)
}

suspend fun runTcpProxy(port: Int = 9000, acceptor: suspend ConnectionAcceptorContext.() -> RSocket) {
    ActorSelectorManager(Dispatchers.IO).use { selector ->
        val transport = aSocket(selector).tcp().serverTransport(port = port)

        RSocketServer().bind(transport) {
            acceptor()
        }.join()
    }
}

runBlocking {
    println("running at tcp://localhost:9000")
    runTcpProxy(port = 9000) {
        val url = config.setupPayload.data.readText()
        println("route: $url")
        connectWebsocket(config.payloadMimeType, url)
    }
}