I have a simple gRPC client packaged in a jar by Gradle with shadowJar. When I run the main() with IntelliJ, the RPC is sent successfully. When I run it with java -jar, I get an exception:
Update: I think I've determined that the same set of classes is provided by both IntelliJ and ./gradlew shadowJar, but the order is different. I suspect this causes the divergent behavior but I don't really understand why, or how to control the order of the classpath in either case. It would be a big help if I could figure out which classes are actually relevant here. The full expansion include 19k class files.
Exception in thread "main" io.grpc.StatusException: UNKNOWN
at io.grpc.Status.asException(Status.java:550)
at io.grpc.kotlin.ClientCalls$rpcImpl$1$1$1.onClose(ClientCalls.kt:296)
at io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:562)
at io.grpc.internal.ClientCallImpl.access$300(ClientCallImpl.java:70)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInternal(ClientCallImpl.java:743)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:722)
at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:133)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.nio.channels.UnsupportedAddressTypeException
at java.base/sun.nio.ch.Net.checkAddress(Net.java:146)
at java.base/sun.nio.ch.Net.checkAddress(Net.java:157)
at java.base/sun.nio.ch.SocketChannelImpl.checkRemote(SocketChannelImpl.java:816)
at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:839)
at io.netty.util.internal.SocketUtils$3.run(SocketUtils.java:91)
at io.netty.util.internal.SocketUtils$3.run(SocketUtils.java:88)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:569)
at io.netty.util.internal.SocketUtils.connect(SocketUtils.java:88)
at io.netty.channel.socket.nio.NioSocketChannel.doConnect(NioSocketChannel.java:322)
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.connect(AbstractNioChannel.java:248)
at io.netty.channel.DefaultChannelPipeline$HeadContext.connect(DefaultChannelPipeline.java:1342)
at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:548)
at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:533)
at io.netty.channel.ChannelDuplexHandler.connect(ChannelDuplexHandler.java:54)
at io.grpc.netty.WriteBufferingAndExceptionHandler.connect(WriteBufferingAndExceptionHandler.java:157)
at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:548)
at io.netty.channel.AbstractChannelHandlerContext.access$1000(AbstractChannelHandlerContext.java:61)
at io.netty.channel.AbstractChannelHandlerContext$9.run(AbstractChannelHandlerContext.java:538)
at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:174)
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:167)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:503)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:995)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
... 1 more
my client (which does not appear to be the issue):
fun main() {
runBlocking {
SampleClient().hello("hello")
}
}
class SampleClient() : Closeable {
private val channel = ManagedChannelBuilder.forAddress("localhost", StationController.PORT).usePlaintext().build()
private val stub = StationServiceGrpcKt.StationServiceCoroutineStub(channel)
suspend fun hello(msg: String) {
val request = helloRequest { message = msg }
stub.hello(request)
}
override fun close() {
channel.shutdown().awaitTermination(5, TimeUnit.SECONDS)
}
}
Running with java -jar build/libs/test-0.1-all.jar fails with the above exception. Running with java -classpath <very long classpath> com.test.MainKt succeeds.
I tried to minimize my gradle.build.kts that still shows this behavior:
import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
import com.google.protobuf.gradle.*
plugins {
kotlin("jvm") version "1.7.10"
id("com.github.johnrengelman.shadow") version "6.0.0"
id("com.google.protobuf") version "0.8.19"
}
// These address this error:
// 'compileJava' task (current target is 17) and 'compileKotlin' task (current target is 1.8) jvm target compatibility
// should be set to the same Java version.
java { sourceCompatibility = JavaVersion.VERSION_17; targetCompatibility = JavaVersion.VERSION_17 }
tasks.withType<KotlinCompile> { kotlinOptions { jvmTarget = "17" } }
group = "com.test"
version = "0.1"
repositories { mavenCentral() }
dependencies {
implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.3")
implementation("io.grpc:grpc-protobuf:1.48.1")
implementation("io.grpc:grpc-kotlin-stub:1.3.0")
// The rpc fails only when I run it from the fat jar. running from intellij works. the stacktrace is all in netty,
// but when I compile without netty there is no netty in the jar, making me think there is no transitive dependency
// on netty. it fails with both netty and netty-shaded, but with different stack traces.
// with netty-shaded, it says Caused by: io.grpc.netty.shaded.io.netty.channel.AbstractChannel$AnnotatedConnectException: connect(..) failed: Address family not supported by protocol: /localhost:8980
// with netty, it just says Caused by: java.nio.channels.UnsupportedAddressTypeException
implementation("io.grpc:grpc-netty:1.48.1")
implementation("com.google.protobuf:protobuf-kotlin:3.21.4")
}
// for gRPC
protobuf {
protoc { artifact = "com.google.protobuf:protoc:3.21.4" }
plugins {
// We only need this for Kotlin, but it doesn't fully link without the java sources.
id("grpc") { artifact = "io.grpc:protoc-gen-grpc-java:1.48.1" }
id("grpckt") { artifact = "io.grpc:protoc-gen-grpc-kotlin:1.3.0:jdk8@jar" }
}
generateProtoTasks {
all().forEach {
it.plugins { id("grpc"); id("grpckt") }
// The plugins above (I think) generate the Java proto code, but not the extra Kotlin stuff like DSLs.
// Including this adds a /kotlin folder to the generated code which contains all the extra stuff.
it.builtins { id("kotlin") }
}
}
}
sourceSets {
main {
java {
// These are the default generated source dirs, but they have to be added manually currently:
// https://github.com/google/protobuf-gradle-plugin/issues/109
// The plugin generates both a grpc dir with Java files, and grpckt with Kotlin files. I believe the grpckt
// contents includes all the functionality of the grpc (java) contents, but I'm not positive. The kotlin
// files might just be stubs for the java version? so maybe this compiles but doesn't run?
srcDirs("build/generated/source/proto/main/grpc")
srcDirs("build/generated/source/proto/main/grpckt")
// This contains the Java classes like the request and response messages.
srcDirs("build/generated/source/proto/main/java")
// This contains the Kotlin extensions to those java classes, like DSLs.
srcDirs("build/generated/source/proto/main/kotlin")
}
}
}
tasks.jar { manifest.attributes["Main-Class"] = "com.test.MainKt" }
I'm at a loss for how to proceed with debugging this.