New Twitter account where we’ll be posting news, tips, etc. https://twitter.com/JetBrainsKtor

How can I serialize class with set of class by

kotlinx-serialization

in 1.3.0? I have

kotlinx.serialization.SerializationException: Can't locate argument-less serializer for class DeviceItems

All examples for older versions

@Serializable
data class DeviceItems(val id: String, val rows: Set<DeviceItem>)

Is there anyway to be notified when a

ByteReadChannel

has been exhausted (or closed)?

Posting this question again, hoping someone will notice and answer: I’m working with push based HTTP API that uses chunked transfer encoding to push messages. I need access to the individual HTTP chunks while reading the response. Is there a way using the ktor HttpClient to get access to the HTTP Chunks?

Do anyone tried multiple configuration something like environment based configuration which spring boot provides???

Folks, we’re looking for case studies / testimonials for Ktor. If you’re using it in production and are open to discuss your usage, please ping me. Thanks.

Can I direct some attention to https://github.com/ktorio/ktor/issues/1266 . Doing without this feature is really problematic

Hi there! I have a question about Ktor. Was it intended as a techdemo only? I've read on reddit that some people think that it was not meant for production use. Is this true?

I would like like to create a routes in programatic way instead of using dsl. Is there any sample available on this?

Hi, my app is acting like a proxy between the client app and server. A client makes a request, if cached data is valid i.e. not expired, I serve him that, otherwise I make a request to the server, get data, cache it, and then serve it to the client. I wrote some code, but it's not thread-safe. How can I improve this so I do not make unnecessary requests to the server?

fun Application.module() {
    val client = HttpClient(OkHttp) {
        install(JsonFeature) {
            serializer = GsonSerializer()
        }
    }
    var cached: Data? = null
    routing {
        get("/") {
            if (cached == null) {
                val new = client.get<Data>("<https://my-host.com/message>")
                cached = new
            }
            if (cached!!.expires < System.currentTimeMillis()) {
                val new = client.get<Data>("<https://my-host.com/message>")
                cached = new
            }
            call.respond(cached!!.message)
        }
    }
}

data class Data(val expires: Long, val message: String)

Hi guys, I have a kotlin multiplatform project that is used as a module in iOS app and Android app to act as Data Repository. I am trying to implement a method to upload files in this KMP Module that can be accessed from iOS app code and Android App Code. Is there any documented way or some blog posts that help this scenario?

Good day, I'm struggling to set

cookie.secure = true

as my server is throwing. I've been trying to work through this to no success. Here's the top of the stacktrace:

10:15:06.019 [ktor-jetty-10001-1] ERROR Application - 500 Internal Server Error: GET - /cloud/v1/vault
java.lang.IllegalArgumentException: You should set secure cookie only via secure transport (HTTPS)
	at io.ktor.response.ResponseCookies.append(ResponseCookies.kt:30)
	at io.ktor.sessions.SessionTransportCookie.send(SessionTransportCookie.kt:52)
	at io.ktor.sessions.SessionsKt.sendSessionData(Sessions.kt:214)
	at io.ktor.sessions.Sessions$Feature$install$2.invokeSuspend(Sessions.kt:76)
	at io.ktor.sessions.Sessions$Feature$install$2.invoke(Sessions.kt)
	at io.ktor.util.pipeline.SuspendFunctionGun.loop(PipelineContext.kt:318)
	at io.ktor.util.pipeline.SuspendFunctionGun.proceed(PipelineContext.kt:163)
	at io.ktor.util.pipeline.SuspendFunctionGun.execute(PipelineContext.kt:183)
	at io.ktor.util.pipeline.Pipeline.execute(Pipeline.kt:27)

I'm running my ktor behind an nginx proxy which terminates https and passes the request on via reverse proxy to the ktor server. Nginx is forwarding these X-Forwarded headers:

"X-Forwarded-For": "[omitted]",
  "X-Forwarded-Proto": "[https]",

And nginx conf block:

location /cloud/v1 {
  proxy_set_header X-Forwarded-For $remote_addr;
  proxy_set_header X-Forwarded_Proto 'https';
  proxy_pass <http://127.0.0.1:10001>;
}

In my ktor server setup i have:

install(XForwardedHeaderSupport)

As far as I have read, this should now be working but I am still getting the error. I have logged out

call.request.origin.scheme

inside one of my controllers and its returning

http

so it appears that the XForwadedHeaderSupport isn't setting the scheme to

https

... any suggestions?! 🙏

Kotlin 1.4 M2 released, Ktor support for native-mt coroutines Coming soon™️

Guys, i wanted to build Ktor from the source, but the IDEA isn't helpful at all. Like, it doesn't even register that there is a gradle build script there.. so it doesn't even know that this is a gradle project. What's your experience with building Ktor from source? Any advice?

this seems related: https://github.com/Kotlin/kotlinx.html/issues/147

https://api.ktor.io/1.3.2/io.ktor.client.statement/read-text.html How come this responds with an error if the response code is not 200?

HttpClient().use { client ->
 val response = client.submitForm<HttpResponse>(
  url = "<https://discord.com/api/oauth2/token>",
  formParameters = Parameters.build {
   append("client_id", config.discord.client)
   append("client_secret", config.discord.secret)
   append("grant_type", "authorization_code")
   append("redirect_uri", config.discord.redirect)
   append("scope", "identify")
   append("code", code)
  })
  println(response.readText()) // throws an error if response status is not 200.
}

Hi guys, I have a Ktor

HttpClient

set like so:

HttpClient(engine) {
    defaultRequest {
        header("A Header", headerValue)
    }
}

I wanted to add a test to that ensures that everytime I make a request to the

HttpClient

it would add the stated header. Is there a way to do this test?

Hi guys. Curious as to how you handle async in KTor server. We have withContext(Dispatchers.IO) {...} on the slowest calls but not everything. Do you do async on everything? I suspect some requests on our end are "slow" because of queuing requests. Is there some way to log/analyse queue length? I can't find anything that lets me tap into that as a metric...

Anyone having

DoubleReceiveException

issue? How did you work around this?

Hello guys, I need some help regarding the usage of the application.conf file. I have a service which reads his configuration from application.conf:

class MqttHandler : SensorExchangeUseCase {
    /**
     *  Factory to read the application.conf file
     *  <https://stackoverflow.com/questions/53891189/how-do-i-use-custom-configuration-in-ktor>
     */
    private val config: MqttConfig = with(ConfigFactory.load()) {
        MqttConfig(
            this.getString("mqtt.topic"),
            getString("mqtt.brokerUrl"),
            getInt("mqtt.port"),
            getString("mqtt.clientId")
        )
    }

To test that, I created the following test:

class MqttHandlerTest : FunSpec({
    withTestApplication {
        (environment.config as MapApplicationConfig).apply {
            put("mqtt.topic", "karlheinz")
            put("mqtt.brokerUrl", container.host)
            put("mqtt.port", port.toString())
            put("mqtt.clientId", "Karl")
        }
        main()
    }


    test("should read correct Config from HOCON File") {
        with(ConfigFactory.load()) {
            getString("mqtt.topic") shouldBe "karlheinz"
            getString("mqtt.brokerUrl") shouldBe container.host
            getInt("mqtt.port") shouldBe port
            getString("mqtt.clientId") shouldBe "Karl"
        }
    }

However, my test fails since it loads the values which are in my local file and not the values that I put there with

withTestApplication

. My Service is not an application module. How could I test the behaviour? It feels like I'm missing something. Thanks in advance!

After a quick search on this channel and the web, it looks like to me there is no convenient way of setting a base url value? I saw people suggested to use this

HttpClient(CIO) {
        defaultRequest {
            url {
                host = "<https://my.host.com>"
                port = 443
            }
        }
        install(JsonFeature) {
            serializer = GsonSerializer()
        }
    }

I does not work when I try to use it with

client.get<ApiResponse<Character>>("/endpoint")

Am I doing anything wrong?

📣 Ktor

1.3.2-1.4-M2

has been released with Kotlin 1.4-M2 support

Hi All, I'm trying to configure a server to use

build.gradle.kts

instead of

build.gradle

. When I configure it from the wizard and build it works fine out of the box. When I convert the file I get the following error.

INFO  Application - No ktor.deployment.watch patterns specified, automatic reload is not active
Exception in thread "DefaultDispatcher-worker-3" java.lang.ClassNotFoundException: Module function cannot be found for the fully qualified name 'com.example.ApplicationKt.module'

This is my

build.gradle.kts

file

buildscript {
    repositories {
        jcenter()
        mavenCentral()
        maven{
            url = uri("<https://kotlin.bintray.com/ktor>")
            url = uri("<https://kotlin.bintray.com/kotlinx>")
        }
    }
    
    dependencies {
        classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.72")
    }
}

//Setup the application plugins
plugins {
    application
    kotlin("jvm") version "1.3.72"
}

group = "com.example"
version = "0.0.1"

application {
    mainClassName = "io.ktor.server.cio.EngineMain"
}

sourceSets["main"].resources.srcDirs("resources")
sourceSets["test"].resources.srcDirs("testresources")

repositories {
    mavenCentral()
    mavenLocal()
    jcenter()
    maven{
        url = uri("<https://kotlin.bintray.com/ktor>")
        url = uri("<https://kotlin.bintray.com/kotlinx>")
    }
}

dependencies {
    implementation(kotlin("stdlib-jdk8"))
    implementation("io.ktor:ktor-server-cio:1.3.2")
    implementation("ch.qos.logback:logback-classic:1.2.1")
    implementation("io.ktor:ktor-server-core:1.3.2")
    implementation("io.ktor:ktor-locations:1.3.2")
    implementation("io.ktor:ktor-metrics:1.3.2")
    implementation("io.ktor:ktor-client-core:1.3.2")
    implementation("io.ktor:ktor-client-core-jvm:1.3.2")
    implementation("io.ktor:ktor-client-cio:1.3.2")
    implementation("io.ktor:ktor-client-json-jvm:1.3.2")
    implementation("io.ktor:ktor-client-gson:1.3.2")
    implementation("io.ktor:ktor-client-logging-jvm:1.3.2")
    testImplementation("io.ktor:ktor-server-tests:1.3.2")
}

Im not really sure why its not picking it up.

How can I add ktor-client-CIO to KN with “1.3.2-1.4-M2”? I try to create macosX64 compile 1. When I add dependencies

ktor-client-core

and

ktor-http-cio

I’ve had a error

Could not find "io.ktor:ktor-io-cinterop-bits" in...

2. When I add dependencies

ktor-client-core

and

ktor-client-cio

I’ve had a error

No matching variant of io.ktor:ktor-client-cio:1.3.2-1.4-M2 was found

3. When I add dependencies

ktor-client-core

and

ktor-client-cio-kotlinMultiplatform

I’ve had a error

Could not find "io.ktor:ktor-io-cinterop-bits" in...

How can I do it?

Hi, I found how to use `FileReader`etc to upload an image with multipart requests, but I don't understand how I can unit test it. I'm searching for a way to get access to a JS

File

or

Blob

from a URL (it's a PNG image). I found the example that shows how to do this with Kotlin/JVM, but nothing for Kotlin/JS at the moment. Is it possible?

Hi there! Do any of you know how can I use

call.receiveParameters()

when I use the content negotiation module? I get

kotlinx.serialization.SerializationException: Can't locate argument-less serializer for class Parameters. For generic classes, such as lists, please provide serializer explicitly.

How do I provide a serializer for Parameters? Or a Map? I'm using the kotlinx.serialization serializer like this:

import io.ktor.application.Application
import io.ktor.application.install
import io.ktor.features.ContentNegotiation
import io.ktor.serialization.json

fun Application.configureContentNegotiation() {
    install(ContentNegotiation) {
        json()
    }
}

I also checked the docs but I did not find any examples for this.

Hi, I have no

kotlin

skills, but I am trying to add it (in fact upgrade to 1.3) in https://github.com/the-benchmarker/web-frameworks/pull/2951 Could someone help me ? I have some messages

Class 'kotlin.Unit' is compiled by a pre-release version of Kotlin and cannot be loaded by this version of the compiler

on

gradle

6.5 and

kotlin

1.3.72

Hey everyone, I’m getting the following error while trying to test my repository logic

Cannot access '<http://java.io|java.io>.Closeable' which is a supertype of 'io.ktor.client.HttpClient'. Check your module classpath for missing or conflicting dependencies kotlin multiplatform

Can someone help?

Hi all. I am working on multiplatform project that using websocket protocol. Does ktor support now websocket on iOS? Want to move all network communication in common code and implement all websocket logic there using ktor.

Is there any know problem with memory leak in Ktor on iOS? 🤔 I’m running an app where I’m just polling api every 1 sec and memory on iOS emulator just keeps growing.