Add optional OpenTelemetry Netty server instrumentation

- Update lys.version to 2026.04.14

- Add optional compileOnly dependency on opentelemetry-netty-4.1 in rbcs-server

- Add runtime guard to only activate instrumentation when OTel classes are on classpath

- Insert OTel combined handler after HttpServerCodec in the Netty pipeline

- Add requires-static JPMS directives for optional module support

- Add enableTelemetry config attribute to rbcs:server with default false

- Update Configuration DTO, XSD schema, Parser, Serializer, and all tests
This commit is contained in:
OpenCode
2026-04-28 14:59:08 +00:00
parent 70eccf83a8
commit ee7bc7e850
198 changed files with 11040 additions and 4 deletions
Binary file not shown.
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package net.woggioni.rbcs.cli
import net.woggioni.jwo.Application
import net.woggioni.rbcs.cli.impl.AbstractVersionProvider
import net.woggioni.rbcs.cli.impl.RbcsCommand
import net.woggioni.rbcs.cli.impl.commands.BenchmarkCommand
import net.woggioni.rbcs.cli.impl.commands.ClientCommand
import net.woggioni.rbcs.cli.impl.commands.GetCommand
import net.woggioni.rbcs.cli.impl.commands.HealthCheckCommand
import net.woggioni.rbcs.cli.impl.commands.PasswordHashCommand
import net.woggioni.rbcs.cli.impl.commands.PutCommand
import net.woggioni.rbcs.cli.impl.commands.ServerCommand
import net.woggioni.rbcs.common.RbcsUrlStreamHandlerFactory
import net.woggioni.rbcs.common.createLogger
import picocli.CommandLine
import picocli.CommandLine.Model.CommandSpec
@CommandLine.Command(
name = "rbcs", versionProvider = RemoteBuildCacheServerCli.VersionProvider::class
)
class RemoteBuildCacheServerCli : RbcsCommand() {
class VersionProvider : AbstractVersionProvider()
companion object {
private fun setPropertyIfNotPresent(key: String, value: String) {
System.getProperty(key) ?: System.setProperty(key, value)
}
fun createCommandLine() : CommandLine {
setPropertyIfNotPresent("logback.configurationFile", "net/woggioni/rbcs/cli/logback.xml")
setPropertyIfNotPresent("io.netty.leakDetectionLevel", "DISABLED")
val currentClassLoader = RemoteBuildCacheServerCli::class.java.classLoader
Thread.currentThread().contextClassLoader = currentClassLoader
if(currentClassLoader.javaClass.name == "net.woggioni.envelope.loader.ModuleClassLoader") {
//We're running in an envelope jar and custom URL protocols won't work
RbcsUrlStreamHandlerFactory.install()
}
val log = createLogger<RemoteBuildCacheServerCli>()
val app = Application.builder("rbcs")
.configurationDirectoryEnvVar("RBCS_CONFIGURATION_DIR")
.configurationDirectoryPropertyKey("net.woggioni.rbcs.conf.dir")
.build()
val rbcsCli = RemoteBuildCacheServerCli()
val commandLine = CommandLine(rbcsCli)
commandLine.setExecutionExceptionHandler { ex, cl, parseResult ->
log.error(ex.message, ex)
CommandLine.ExitCode.SOFTWARE
}
commandLine.addSubcommand(ServerCommand(app))
commandLine.addSubcommand(PasswordHashCommand())
commandLine.addSubcommand(
CommandLine(ClientCommand(app)).apply {
addSubcommand(BenchmarkCommand())
addSubcommand(PutCommand())
addSubcommand(GetCommand())
addSubcommand(HealthCheckCommand())
})
return commandLine
}
@JvmStatic
fun main(vararg args: String) {
System.exit(createCommandLine().execute(*args))
}
}
@CommandLine.Option(names = ["-V", "--version"], versionHelp = true)
var versionHelp = false
private set
@CommandLine.Spec
private lateinit var spec: CommandSpec
override fun run() {
spec.commandLine().usage(System.out);
}
}
@@ -0,0 +1,30 @@
package net.woggioni.rbcs.cli.impl
import java.util.jar.Attributes
import java.util.jar.JarFile
import java.util.jar.Manifest
import picocli.CommandLine
abstract class AbstractVersionProvider : CommandLine.IVersionProvider {
private val version: String
private val vcsHash: String
init {
val mf = Manifest()
javaClass.module.getResourceAsStream(JarFile.MANIFEST_NAME).use { `is` ->
mf.read(`is`)
}
val mainAttributes = mf.mainAttributes
version = mainAttributes.getValue(Attributes.Name.SPECIFICATION_VERSION) ?: throw RuntimeException("Version information not found in manifest")
vcsHash = mainAttributes.getValue(Attributes.Name.IMPLEMENTATION_VERSION) ?: throw RuntimeException("Version information not found in manifest")
}
override fun getVersion(): Array<String?> {
return if (version.endsWith("-SNAPSHOT")) {
arrayOf(version, vcsHash)
} else {
arrayOf(version)
}
}
}
@@ -0,0 +1,19 @@
package net.woggioni.rbcs.cli.impl
import java.nio.file.Path
import net.woggioni.jwo.Application
import picocli.CommandLine
abstract class RbcsCommand : Runnable {
@CommandLine.Option(names = ["-h", "--help"], usageHelp = true)
var usageHelp = false
private set
protected fun findConfigurationFile(app: Application, fileName : String): Path {
val confDir = app.computeConfigurationDirectory(false)
val configurationFile = confDir.resolve(fileName)
return configurationFile
}
}
@@ -0,0 +1,199 @@
package net.woggioni.rbcs.cli.impl.commands
import java.security.SecureRandom
import java.time.Duration
import java.time.Instant
import java.time.temporal.ChronoUnit
import java.util.concurrent.LinkedBlockingQueue
import java.util.concurrent.Semaphore
import java.util.concurrent.atomic.AtomicLong
import kotlin.random.Random
import net.woggioni.jwo.JWO
import net.woggioni.jwo.LongMath
import net.woggioni.rbcs.api.CacheValueMetadata
import net.woggioni.rbcs.cli.impl.RbcsCommand
import net.woggioni.rbcs.cli.impl.converters.ByteSizeConverter
import net.woggioni.rbcs.client.Configuration
import net.woggioni.rbcs.client.RemoteBuildCacheClient
import net.woggioni.rbcs.common.createLogger
import net.woggioni.rbcs.common.debug
import net.woggioni.rbcs.common.error
import net.woggioni.rbcs.common.info
import picocli.CommandLine
@CommandLine.Command(
name = "benchmark",
description = ["Run a load test against the server"],
showDefaultValues = true
)
class BenchmarkCommand : RbcsCommand() {
companion object {
private val log = createLogger<BenchmarkCommand>()
fun execute(profile : Configuration.Profile,
numberOfEntries : Int,
entrySize : Int,
useRandomValue : Boolean,
) {
val progressThreshold = LongMath.ceilDiv(numberOfEntries.toLong(), 20)
RemoteBuildCacheClient(profile).use { client ->
val entryGenerator = sequence {
val random = Random(SecureRandom.getInstance("NativePRNGNonBlocking").nextLong())
while (true) {
val key = JWO.bytesToHex(random.nextBytes(16))
val value = if (useRandomValue) {
random.nextBytes(entrySize)
} else {
val byteValue = random.nextInt().toByte()
ByteArray(entrySize) { _ -> byteValue }
}
yield(key to value)
}
}
log.info {
"Starting insertion"
}
val entries = let {
val completionCounter = AtomicLong(0)
val completionQueue = LinkedBlockingQueue<Pair<String, ByteArray>>(numberOfEntries)
val start = Instant.now()
val semaphore = Semaphore(profile.maxConnections * 5)
val iterator = entryGenerator.take(numberOfEntries).iterator()
while (completionCounter.get() < numberOfEntries) {
if (iterator.hasNext()) {
val entry = iterator.next()
semaphore.acquire()
val future =
client.put(entry.first, entry.second, CacheValueMetadata(null, null)).thenApply { entry }
future.whenComplete { result, ex ->
if (ex != null) {
log.error(ex.message, ex)
} else {
completionQueue.put(result)
}
semaphore.release()
val completed = completionCounter.incrementAndGet()
if (completed.mod(progressThreshold) == 0L) {
log.debug {
"Inserted $completed / $numberOfEntries"
}
}
}
} else {
Thread.sleep(Duration.of(500, ChronoUnit.MILLIS))
}
}
val inserted = completionQueue.toList()
val end = Instant.now()
log.info {
val elapsed = Duration.between(start, end).toMillis()
val opsPerSecond = String.format("%.2f", numberOfEntries.toDouble() / elapsed * 1000)
"Insertion rate: $opsPerSecond ops/s"
}
inserted
}
log.info {
"Inserted ${entries.size} entries"
}
log.info {
"Starting retrieval"
}
if (entries.isNotEmpty()) {
val errorCounter = AtomicLong(0)
val completionCounter = AtomicLong(0)
val semaphore = Semaphore(profile.maxConnections * 5)
val start = Instant.now()
val it = entries.iterator()
while (completionCounter.get() < entries.size) {
if (it.hasNext()) {
val entry = it.next()
semaphore.acquire()
val future = client.get(entry.first).handle { response, ex ->
if(ex != null) {
errorCounter.incrementAndGet()
log.error(ex.message, ex)
} else if (response == null) {
errorCounter.incrementAndGet()
log.error {
"Missing entry for key '${entry.first}'"
}
} else if (!entry.second.contentEquals(response)) {
errorCounter.incrementAndGet()
log.error {
"Retrieved a value different from what was inserted for key '${entry.first}': " +
"expected '${JWO.bytesToHex(entry.second)}', got '${JWO.bytesToHex(response)}' instead"
}
}
}
future.whenComplete { _, _ ->
val completed = completionCounter.incrementAndGet()
if (completed.mod(progressThreshold) == 0L) {
log.debug {
"Retrieved $completed / ${entries.size}"
}
}
semaphore.release()
}
} else {
Thread.sleep(Duration.of(500, ChronoUnit.MILLIS))
}
}
val end = Instant.now()
val errors = errorCounter.get()
val successfulRetrievals = entries.size - errors
val successRate = successfulRetrievals.toDouble() / entries.size
log.info {
"Successfully retrieved ${entries.size - errors}/${entries.size} (${String.format("%.1f", successRate * 100)}%)"
}
log.info {
val elapsed = Duration.between(start, end).toMillis()
val opsPerSecond = String.format("%.2f", entries.size.toDouble() / elapsed * 1000)
"Retrieval rate: $opsPerSecond ops/s"
}
} else {
log.error("Skipping retrieval benchmark as it was not possible to insert any entry in the cache")
}
}
}
}
@CommandLine.Spec
private lateinit var spec: CommandLine.Model.CommandSpec
@CommandLine.Option(
names = ["-e", "--entries"],
description = ["Total number of elements to be added to the cache"],
paramLabel = "NUMBER_OF_ENTRIES"
)
private var numberOfEntries = 1000
@CommandLine.Option(
names = ["-s", "--size"],
description = ["Size of a cache value in bytes"],
paramLabel = "SIZE",
converter = [ByteSizeConverter::class]
)
private var size = 0x1000
@CommandLine.Option(
names = ["-r", "--random"],
description = ["Insert completely random byte values"]
)
private var randomValues = false
override fun run() {
val clientCommand = spec.parent().userObject() as ClientCommand
val profile = clientCommand.profileName.let { profileName ->
clientCommand.configuration.profiles[profileName]
?: throw IllegalArgumentException("Profile $profileName does not exist in configuration")
}
execute(
profile,
numberOfEntries,
size,
randomValues
)
}
}
@@ -0,0 +1,48 @@
package net.woggioni.rbcs.cli.impl.commands
import java.nio.file.Path
import net.woggioni.jwo.Application
import net.woggioni.rbcs.cli.impl.RbcsCommand
import net.woggioni.rbcs.client.Configuration
import net.woggioni.rbcs.common.createLogger
import net.woggioni.rbcs.common.debug
import picocli.CommandLine
@CommandLine.Command(
name = "client",
description = ["RBCS client"],
showDefaultValues = true
)
class ClientCommand(app : Application) : RbcsCommand() {
@CommandLine.Option(
names = ["-c", "--configuration"],
description = ["Path to the client configuration file"],
paramLabel = "CONFIGURATION_FILE"
)
private var configurationFile : Path = findConfigurationFile(app, "rbcs-client.xml")
@CommandLine.Option(
names = ["-p", "--profile"],
description = ["Name of the client profile to be used"],
paramLabel = "PROFILE",
required = false
)
var profileName : String? = null
get() = field ?: throw IllegalArgumentException("A profile name must be specified using the '-p' command line parameter")
val configuration : Configuration by lazy {
Configuration.parse(configurationFile)
}
override fun run() {
val log = createLogger<ClientCommand>()
log.debug {
"Using configuration file '$configurationFile'"
}
println("Available profiles:")
configuration.profiles.forEach { (profileName, _) ->
println(profileName)
}
}
}
@@ -0,0 +1,59 @@
package net.woggioni.rbcs.cli.impl.commands
import java.io.OutputStream
import java.nio.file.Files
import java.nio.file.Path
import net.woggioni.rbcs.cli.impl.RbcsCommand
import net.woggioni.rbcs.client.Configuration
import net.woggioni.rbcs.client.RemoteBuildCacheClient
import net.woggioni.rbcs.common.createLogger
import picocli.CommandLine
@CommandLine.Command(
name = "get",
description = ["Fetch a value from the cache with the specified key"],
showDefaultValues = true
)
class GetCommand : RbcsCommand() {
companion object {
private val log = createLogger<GetCommand>()
fun execute(profile : Configuration.Profile, key : String, outputStream: OutputStream) {
RemoteBuildCacheClient(profile).use { client ->
client.get(key).thenApply { value ->
value?.let {
outputStream.use {
it.write(value)
}
} ?: throw NoSuchElementException("No value found for key $key")
}.get()
}
}
}
@CommandLine.Spec
private lateinit var spec: CommandLine.Model.CommandSpec
@CommandLine.Option(
names = ["-k", "--key"],
description = ["The key for the new value"],
paramLabel = "KEY"
)
private var key : String = ""
@CommandLine.Option(
names = ["-v", "--value"],
description = ["Path to a file where the retrieved value will be written (defaults to stdout)"],
paramLabel = "VALUE_FILE",
)
private var output : Path? = null
override fun run() {
val clientCommand = spec.parent().userObject() as ClientCommand
val profile = clientCommand.profileName.let { profileName ->
clientCommand.configuration.profiles[profileName]
?: throw IllegalArgumentException("Profile $profileName does not exist in configuration")
}
execute(profile, key, (output?.let(Files::newOutputStream) ?: System.out))
}
}
@@ -0,0 +1,53 @@
package net.woggioni.rbcs.cli.impl.commands
import java.security.SecureRandom
import kotlin.random.Random
import net.woggioni.rbcs.cli.impl.RbcsCommand
import net.woggioni.rbcs.client.Configuration
import net.woggioni.rbcs.client.RemoteBuildCacheClient
import net.woggioni.rbcs.common.createLogger
import picocli.CommandLine
@CommandLine.Command(
name = "health",
description = ["Check server health"],
showDefaultValues = true
)
class HealthCheckCommand : RbcsCommand() {
companion object{
private val log = createLogger<HealthCheckCommand>()
fun execute(profile : Configuration.Profile) {
RemoteBuildCacheClient(profile).use { client ->
val random = Random(SecureRandom.getInstance("NativePRNGNonBlocking").nextLong())
val nonce = ByteArray(0xa0)
random.nextBytes(nonce)
client.healthCheck(nonce).thenApply { value ->
if(value == null) {
throw IllegalStateException("Empty response from server")
}
val offset = value.size - nonce.size
for(i in 0 until nonce.size) {
val a = nonce[i]
val b = value[offset + i]
if(a != b) {
throw IllegalStateException("Server nonce does not match")
}
}
}.get()
}
}
}
@CommandLine.Spec
private lateinit var spec: CommandLine.Model.CommandSpec
override fun run() {
val clientCommand = spec.parent().userObject() as ClientCommand
val profile = clientCommand.profileName.let { profileName ->
clientCommand.configuration.profiles[profileName]
?: throw IllegalArgumentException("Profile $profileName does not exist in configuration")
}
execute(profile)
}
}
@@ -0,0 +1,37 @@
package net.woggioni.rbcs.cli.impl.commands
import java.io.OutputStream
import java.io.OutputStreamWriter
import java.io.PrintWriter
import net.woggioni.jwo.UncloseableOutputStream
import net.woggioni.rbcs.cli.impl.RbcsCommand
import net.woggioni.rbcs.cli.impl.converters.OutputStreamConverter
import net.woggioni.rbcs.common.PasswordSecurity.hashPassword
import picocli.CommandLine
@CommandLine.Command(
name = "password",
description = ["Generate a password hash to add to RBCS configuration file"],
showDefaultValues = true
)
class PasswordHashCommand : RbcsCommand() {
@CommandLine.Option(
names = ["-o", "--output-file"],
description = ["Write the output to a file instead of stdout"],
converter = [OutputStreamConverter::class],
showDefaultValue = CommandLine.Help.Visibility.NEVER,
paramLabel = "OUTPUT_FILE"
)
private var outputStream: OutputStream = UncloseableOutputStream(System.out)
override fun run() {
val password1 = String(System.console().readPassword("Type your password:"))
val password2 = String(System.console().readPassword("Type your password again for confirmation:"))
if(password1 != password2) throw IllegalArgumentException("Passwords do not match")
PrintWriter(OutputStreamWriter(outputStream, Charsets.UTF_8)).use {
it.println(hashPassword(password1))
}
}
}
@@ -0,0 +1,113 @@
package net.woggioni.rbcs.cli.impl.commands
import java.io.InputStream
import java.nio.file.Files
import java.nio.file.Path
import java.util.UUID
import net.woggioni.jwo.Hash
import net.woggioni.jwo.JWO
import net.woggioni.jwo.NullOutputStream
import net.woggioni.rbcs.api.CacheValueMetadata
import net.woggioni.rbcs.cli.impl.RbcsCommand
import net.woggioni.rbcs.client.Configuration
import net.woggioni.rbcs.client.RemoteBuildCacheClient
import net.woggioni.rbcs.common.createLogger
import picocli.CommandLine
@CommandLine.Command(
name = "put",
description = ["Add or replace a value to the cache with the specified key"],
showDefaultValues = true
)
class PutCommand : RbcsCommand() {
companion object {
private val log = createLogger<PutCommand>()
fun execute(profile: Configuration.Profile,
actualKey : String,
inputStream: InputStream,
mimeType : String?,
contentDisposition: String?
) {
RemoteBuildCacheClient(profile).use { client ->
inputStream.use {
client.put(actualKey, it.readAllBytes(), CacheValueMetadata(contentDisposition, mimeType))
}.get()
println(profile.serverURI.resolve(actualKey))
}
}
}
@CommandLine.Spec
private lateinit var spec: CommandLine.Model.CommandSpec
@CommandLine.Option(
names = ["-k", "--key"],
description = ["The key for the new value, randomly generated if omitted"],
paramLabel = "KEY"
)
private var key : String? = null
@CommandLine.Option(
names = ["-i", "--inline"],
description = ["File is to be displayed in the browser"],
paramLabel = "INLINE",
)
private var inline : Boolean = false
@CommandLine.Option(
names = ["-t", "--type"],
description = ["File mime type"],
paramLabel = "MIME_TYPE",
)
private var mimeType : String? = null
@CommandLine.Option(
names = ["-v", "--value"],
description = ["Path to a file containing the value to be added (defaults to stdin)"],
paramLabel = "VALUE_FILE",
)
private var value : Path? = null
override fun run() {
val clientCommand = spec.parent().userObject() as ClientCommand
val profile = clientCommand.profileName.let { profileName ->
clientCommand.configuration.profiles[profileName]
?: throw IllegalArgumentException("Profile $profileName does not exist in configuration")
}
RemoteBuildCacheClient(profile).use { client ->
val inputStream : InputStream
val mimeType : String?
val contentDisposition : String?
val valuePath = value
val actualKey : String?
if(valuePath != null) {
inputStream = Files.newInputStream(valuePath)
mimeType = this.mimeType ?: Files.probeContentType(valuePath)
contentDisposition = if(inline) {
"inline"
} else {
"attachment; filename=\"${valuePath.fileName}\""
}
actualKey = key ?: let {
val md = Hash.Algorithm.SHA512.newInputStream(Files.newInputStream(valuePath)).use {
JWO.copy(it, NullOutputStream())
it.messageDigest
}
UUID.nameUUIDFromBytes(md.digest()).toString()
}
} else {
inputStream = System.`in`
mimeType = this.mimeType
contentDisposition = if(inline) {
"inline"
} else {
null
}
actualKey = key ?: UUID.randomUUID().toString()
}
execute(profile, actualKey, inputStream, mimeType, contentDisposition)
}
}
}
@@ -0,0 +1,90 @@
package net.woggioni.rbcs.cli.impl.commands
import java.io.ByteArrayOutputStream
import java.nio.file.Files
import java.nio.file.Path
import java.time.Duration
import java.util.concurrent.TimeUnit
import net.woggioni.jwo.Application
import net.woggioni.jwo.JWO
import net.woggioni.rbcs.cli.impl.RbcsCommand
import net.woggioni.rbcs.cli.impl.converters.DurationConverter
import net.woggioni.rbcs.common.createLogger
import net.woggioni.rbcs.common.debug
import net.woggioni.rbcs.common.info
import net.woggioni.rbcs.server.RemoteBuildCacheServer
import net.woggioni.rbcs.server.RemoteBuildCacheServer.Companion.DEFAULT_CONFIGURATION_URL
import picocli.CommandLine
@CommandLine.Command(
name = "server",
description = ["RBCS server"],
showDefaultValues = true
)
class ServerCommand(app : Application) : RbcsCommand() {
companion object {
private val log = createLogger<ServerCommand>()
}
private fun createDefaultConfigurationFile(configurationFile: Path) {
log.info {
"Creating default configuration file at '$configurationFile'"
}
val defaultConfigurationFileResource = DEFAULT_CONFIGURATION_URL
Files.newOutputStream(configurationFile).use { outputStream ->
defaultConfigurationFileResource.openStream().use { inputStream ->
JWO.copy(inputStream, outputStream)
}
}
}
@CommandLine.Option(
names = ["-t", "--timeout"],
description = ["Exit after the specified time"],
paramLabel = "TIMEOUT",
converter = [DurationConverter::class]
)
private var timeout: Duration? = null
@CommandLine.Option(
names = ["-c", "--config-file"],
description = ["Read the application configuration from this file"],
paramLabel = "CONFIG_FILE"
)
private var configurationFile: Path = findConfigurationFile(app, "rbcs-server.xml")
override fun run() {
if (!Files.exists(configurationFile)) {
Files.createDirectories(configurationFile.parent)
createDefaultConfigurationFile(configurationFile)
}
log.debug {
"Using configuration file '$configurationFile'"
}
val configuration = RemoteBuildCacheServer.loadConfiguration(configurationFile)
log.debug {
ByteArrayOutputStream().also {
RemoteBuildCacheServer.dumpConfiguration(configuration, it)
}.let {
"Server configuration:\n${String(it.toByteArray())}"
}
}
val server = RemoteBuildCacheServer(configuration)
val handle = server.run()
val shutdownHook = Thread.ofPlatform().unstarted {
handle.sendShutdownSignal()
try {
handle.get(60, TimeUnit.SECONDS)
} catch (ex : Throwable) {
log.warn(ex.message, ex)
}
}
Runtime.getRuntime().addShutdownHook(shutdownHook)
if(timeout != null) {
Thread.sleep(timeout)
handle.sendShutdownSignal()
}
handle.get()
}
}
@@ -0,0 +1,10 @@
package net.woggioni.rbcs.cli.impl.converters
import picocli.CommandLine
class ByteSizeConverter : CommandLine.ITypeConverter<Int> {
override fun convert(value: String): Int {
return Integer.decode(value)
}
}
@@ -0,0 +1,11 @@
package net.woggioni.rbcs.cli.impl.converters
import java.time.Duration
import picocli.CommandLine
class DurationConverter : CommandLine.ITypeConverter<Duration> {
override fun convert(value: String): Duration {
return Duration.parse(value)
}
}
@@ -0,0 +1,13 @@
package net.woggioni.rbcs.cli.impl.converters
import java.io.InputStream
import java.nio.file.Files
import java.nio.file.Paths
import picocli.CommandLine
class InputStreamConverter : CommandLine.ITypeConverter<InputStream> {
override fun convert(value: String): InputStream {
return Files.newInputStream(Paths.get(value))
}
}
@@ -0,0 +1,13 @@
package net.woggioni.rbcs.cli.impl.converters
import java.io.OutputStream
import java.nio.file.Files
import java.nio.file.Paths
import picocli.CommandLine
class OutputStreamConverter : CommandLine.ITypeConverter<OutputStream> {
override fun convert(value: String): OutputStream {
return Files.newOutputStream(Paths.get(value))
}
}