Hey everyone, I’m using websockets from ktor server and client in a side project. Recently, I discovered that my client agents are disconnecting due to an internet connectivity issue and not realizing they’ve lost the connection, meanwile the server is well aware of disconnection. I’ve been using DefaultWebSocketImpl which means ping-pong should have caught this issue. After some digging, it turns out that ping-pong mechanism actually is not enabled by default on client sockets. Although client WebSockets feature takes

pingInterval

and

maxFrameSize

as constructor parameters,

install(WebSockets)

does not have a configuration option. So, I’m now stuck, not able to turn on a feature that already exists. Furthermore,

maxFrameSize

is passed to

DefaultWebSocketSession

as

return DefaultWebSocketSession(this, pingInterval, maxFrameSize)

it turns out, third parameter is actually

timeoutMillis

not related to frameSize at all. I’ve made necessary changes to client WebSockets feature to actually take configuration and added

timeoutMillis

. Do you think I should make a pull request? It is a really small change and backward compatible.

Hi, we have this sealed class:

@Serializable
sealed class PaymentResult {
    @Serializable
    object Authorised : PaymentResult()
    @Serializable
    data class Error(val refusalReason: String) : PaymentResult()
    @Serializable
    data class Refused(val refusalReason: String, val refusalReasonCode: String) : PaymentResult()
}

we have installed json content negotiation:

install(ContentNegotiation) {
    json(json)
}

we respond with:

call.respond(PaymentResult.Authorised)

currently it returns:

{}

is it possible to use polymorphic serializer for responses?

Minor complaint, but there aren’t any first-class helpers for creating asynchronous instances of client requests? I know you can easily do

async { request { } }

but still would nice to eliminate the boilerplate.

I'm getting these errors by running a Ktor project in a Docker container. Can anyone help?

Mar 26, 2020 9:58:28 PM io.grpc.internal.ManagedChannelImpl$1 uncaughtException
SEVERE: [Channel<1>: (<http://firestore.googleapis.com:443|firestore.googleapis.com:443>)] Uncaught exception in the SynchronizationContext. Panic!
java.lang.IllegalStateException: Could not find policy 'pick_first'. Make sure its implementation is either registered to LoadBalancerRegistry or included in META-INF/services/io.grpc.LoadBalancerProvider from your jar files.

2020-03-26 22:08:04.961 [nioEventLoopGroup-4-1] ERROR Application - Unhandled exception caught for CoroutineName(call-handler)
com.google.api.gax.rpc.InternalException: io.grpc.StatusRuntimeException: INTERNAL: Panic! This is a bug!

Is there someone from the Ktor team that would be able to assist me in tracking down memory leaks ( https://kotlinlang.slack.com/archives/C3SGXARS6/p1585269741051100 ) in a Kotlin Native program (targets linuxX64)?

Hello, help me please!!)) I try build my lib with ktor 1.3.2, but get error: Could not resolve all files for configuration ‘:androidCompileClasspath’. Could not find io.ktor:ktor-client-android:1.3.2. In maven repositories

mavenLocal()
maven { url "<https://kotlin.bintray.com/kotlinx>" }
mavenCentral()

I just upgraded from ktor 1.2.6 to 1.3.2 and my httpClient hangs on MacOSX. I'm using a manual dispatcher like described in https://github.com/Kotlin/kotlinx.coroutines/issues/470#issuecomment-440080970. Any idea what I'm doing wrong ?

actual fun macOSMain() {
    GlobalScope.launch(mainDispatcher) {
        val response = HttpClient {
        }.get<HttpResponse>("<https://google.com/>") {
        }
        println("response status is: ${response.status}")
    }
    CFRunLoopRun()
}

Full repo at: https://github.com/martinbonnin/kmpCli/blob/ktor-hangs

How a set a default timezone in ktor ?

Hi, is it possible to enforce required/optional fields in JSON serialization? It seems that kotlinx.serialization does the job of enforcing that fields should be required if no defaults are provided, but I was wondering if I can make some optional by saying it’s nullable with e.g.

String?

or

Optional<String>

?

hi all. I'm using kotlinx serialization, but i'm getting this error:

Hello guys! Is there a counterpart for OkHttp's interceptor in the common code? I'm trying to implement an authentication interceptor for refreshing oauth tokens. I've been using OkHttp but it's only for Android. I created a

defaultRequest

block and set up the Authorization header there but I can't seem to find anything to "intercept" it if it needs to be refreshed. Thanks in advance!

Has anyone seen this exception? I basically get it on every request (ktor 1.3.2 running in docker in an openshift environment) but everything seems to work fine (i see the output as DEBUG)

2020-03-31 12:14:53.832 [nioEventLoopGroup-4-2] DEBUG Application - 200 OK: GET - /api/repositories/1/matrices/1/data
2020-03-31 12:15:07.621 [nioEventLoopGroup-3-2] DEBUG Application - I/O operation failed
<http://java.io|java.io>.IOException: Connection reset by peer
	at java.base/sun.nio.ch.FileDispatcherImpl.read0(Native Method)
	at java.base/sun.nio.ch.SocketDispatcher.read(Unknown Source)
	at java.base/sun.nio.ch.IOUtil.readIntoNativeBuffer(Unknown Source)
	at java.base/sun.nio.ch.IOUtil.read(Unknown Source)
	at java.base/sun.nio.ch.IOUtil.read(Unknown Source)
	at java.base/sun.nio.ch.SocketChannelImpl.read(Unknown Source)
	at io.netty.buffer.PooledByteBuf.setBytes(PooledByteBuf.java:251)
	at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:1133)
	at io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:350)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:148)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:714)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:650)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:576)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Unknown Source)

When using the

ContentNegotiation

feature with Jackson for JSON bodies Ktor responds with HTTP 500 if the client sends invalid JSON or JSON that does not match the data classes I am trying to receive. I would expect HTTP 400 instead. Is there a way to configure this?

I’m looking into configuring the

Accept-Encoding

header for my Ktor

HttpClient

. I found the

ContentEncoding

feature (https://github.com/ktorio/ktor/blob/master/ktor-client/ktor-client-features/ktor-client-encoding/common/src/ContentEncoding.kt) but I don’t see that

compression

package in my

ktor-client-core-jvm

jar. Is it published under a separate artifact? Or am I just looking for it in the wrong place?

Why is Ktor client sending

Accept: application/xml;application/json

header when I call:

<http://httpClient.post|httpClient.post>(serviceUrl) {
                contentType(ContentType.Application.Json)
                accept(ContentType.Application.Xml)
                body = MyClass(...)
            }

Does such header even conform to HTTP standard?

Hello! Does anyone have some nice example of Ktor HTTP Client websockets usage that works with flow instead of raw channels?

Is it normal that

Job.cancel()

throws a

CancellationException

itself? Or is this a bug in Ktor?

java.util.concurrent.CancellationException: Job was cancelled
    at io.ktor.client.engine.UtilsKt$attachToUserJob$cleanupHandler$1.invoke(Utils.kt:77)
    at io.ktor.client.engine.UtilsKt$attachToUserJob$cleanupHandler$1.invoke(Unknown Source:2)
    …
    at kotlinx.coroutines.JobSupport.cancel(JobSupport.kt:614)
    at kotlinx.coroutines.Job$DefaultImpls.cancel$default(Job.kt:164)

Simple question: How does one schedule a task in Ktor? Code seems to indicate it is capable but docs are missing... "as soon as you have to reverse engineer someone else's library to use it you should question whether you should be using it for anything meaningful", says me, lol. Here is how spring does it:

@Scheduled(fixedRate = 60000)

hmm, it worked when I imported

ktor-client-gson

instead. I guess that's because I needed an implementation?

hey! i saw that ktor implements features for authentication. is there also a framework for authorization? i have a server in our organisation which basically can do RBAC and ABAC and handles access to resources. so in each call to my ktor app i have to make a http request to that server and check for authorization. how would i handle that? any suggestions? add an interceptor after the autentication pipeline? do it directly in my routes?

Hi, is there a way to bind to a dynamic port with ktor instead of a fixed port?

This is only ktor-adjacent, but I'm looking at ktor's application.conf setup and would like to re-use this functionality for my own configuration classes. I've discovered I can call

HoconApplicationConfig(ConfigFactory.load()).property("apiKey")

, but this gets cumbersome - is there a way to define a class (or data class) and have its values automatically instantiated from application.conf values?

hey is there a prefered/recommended library to use for sending emails?

Hi, I’m trying to handle a response from a ReST API with Ktor Client. This API has several types of response depending if it is a success or an error. I’m trying to handle this with a Sealed class. But I fail to do it. I tried using Gson/Jackson and Json. I saw the polymorphic (https://github.com/Kotlin/kotlinx.serialization/blob/master/docs/polymorphism.md) documentation but I have an issue because one of the attributes of the API is ‘type’ and it’s the classDiscriminator by default and I tried to change it with JsonConfiguration but with no success. I am quite stuck. Any help doing this ? Do you a tutorial, some information ? Thanks. If it is needed I can give access to the code in github (https://github.com/herveDarritchon/icndb). Everything is in the Application.kt file (https://raw.githubusercontent.com/herveDarritchon/icndb/master/src/Application.kt)

hello ladies and gentlemen, what do you suggest for validations? I am checking this one: https://github.com/valiktor/valiktor/releases/tag/0.11.0 (@rodolpho.couto thanks). There is also the hibernate validation, but it is not exactly what I am looking for... but I would like to know what else people are using.

hey! i have a question about oauth2. i basically used the code here https://ktor.io/servers/features/authentication/oauth.html . what happens when i pass a invalid scope (just an example) i basically create an endless loop. the callback tries to send an error reponse back to the /oauth endpoint, the endpoint sees "not authenticated" redirects back to my oauth provider it tries to send the error response .. any ideas how to fix it?

it does actually appear this would be the problem as we're using the netty engine and the trace ID is set in a thread local

Hi guys, I have a question regarding Roting feature. I am new in ktor, and trying to use different approaches, for instance for every individual entity I have separate package for controller, service etc.. And I am registrating every controller in my RoutingModule like thils

fun Application.routingModule() {
    val courtEndpoint by KodeinModule.kodein.instance<CourtEndpointImpl>()
    val userEndpoint by KodeinModule.kodein.instance<UserEndpointImpl>()
    val registrationEndpoint by KodeinModule.kodein.instance<RegistrationEndpointImpl>()
    val companyEndpoint by KodeinModule.kodein.instance<CompanyEndpointImpl>()
    val matchEndpoint by KodeinModule.kodein.instance<MatchEndpointImpl>()

    install(Routing) {
        court(courtEndpoint)
        user(userEndpoint)
        registration(registrationEndpoint)
        company(companyEndpoint)
        match(matchEndpoint)
    }
}

Lets say I will have a lot of entities which means I will registrate every routing in that module and I think it will be look not clear as it could be. Is it any approach, to avoid the situation with registration my routes in install section? Thank you

Is it any good tutorial on cookie session authentication that really works?