Should 2.0 docs be the default at this stage?

Hey there. I’m trying to get my head around Ktor2 by creating a simple REST endpoint to manage things called ‘agents’.

@Serializable
data class Agent(val id: Int, val hostname: String, val port: Int)

I’m struggling with handling POST:

@Serializable
@Resource("/api/agents")
data class AgentsRoute(val sort: String? = "id") {
    @Serializable
    @Resource("{id}")
    data class Id(val parent: AgentsRoute = AgentsRoute(), val id: Int)
}

fun Application.agentRoutes() {
    val agentService = AgentService() // Talks to the database

    routing {
        get<AgentsRoute> {
            call.respond(agentService.getAll())
        }
        get<AgentsRoute.Id> { request ->
            val agent = agentService.get(request.id) ?: call.respond(
                HttpStatusCode.NotFound, "Agent not found"
            )
            call.respond(agent)
        }
        post<AgentsRoute> {
            val agent = call.receive<Agent>() // This blows up!
            // TODO
        }
        delete<AgentsRoute.Id> { request ->
            agentService.get(request.id) ?: call.respond(
                HttpStatusCode.NotFound, "Agent not found"
            )
            call.respond(agentService.delete(request.id))
        }
    }
}

I’m having a problem with the

POST

when I post some data to create a new agent:

{
  "hostname": "192.168.1.1",
  "port": 1012
}

Here’s the exception:

2022-04-10 16:51:06.740 [eventLoopGroupProxy-4-1] ERROR Application - Unhandled: POST - /api/agents/
kotlinx.serialization.MissingFieldException: Field 'id' is required for type with serial name 'com.sonalake.snmpsim.model.Agent', but it was missing
        at kotlinx.serialization.internal.PluginExceptionsKt.throwMissingFieldException(PluginExceptions.kt:20)

I understand why it’s happening - the JSON doesn’t contain an id property - but, as I want to create a new agent I don’t want to have to provide one. I had a look at the Ktor 2.0.0 resource-routing code snippet, but it didn’t go further than receiving the request. Any suggests on the idiomatic Ktor 2 way of doing this? Thank you 🙇

Why do I often see ktor apps with the routing module using

install(Routing)

and others just declare routing directly? Is the install for the routing module really optional?

Ktor 2.0: Should you apply @KtorDsl to a custom plugin? To the variable

@KtorDsl val myPlugin = createRouteScopedPlugin("myPlugin, ::Config) {}

AND to

@KtorDsl class Config

too?

📣 Ktor 2.0.0 is now available 📣 https://blog.jetbrains.com/ktor/2022/04/11/ktor-2-0-released/

Hey I want to understand, what is the use of this

ContentNegotiation

in ktor in client side? Can someone guide me.

Is koin still incompatible with ktor 2? If so - is there some alternative?

TL;DR Is there a way how to react to the unauthorized response by the Authentication feature, i.e. do something before (automatically) returning the 401 response? Hi, I have deployed my Ktor app to Heroku. When I make a POST request that uploads a file (via multipart/form-data) while the user is not authorized (token has expired), I got the 401 response as intended on my localhost. I use JWT and the Authentication feature. However, the app on Heroku responds with 503 Server Request Interrupted. It only happens when the token is invalid and the 401 should be returned. What I have found so far is that the socket is connected, some data was sent as part of a response, but then the socket was destroyed without completing the response. My question is, is there a way how to react to the unauthorized response by the Authentication feature, i.e. do something before (automatically) returning the 401 response? In my case catching an exception?

Is there no way to access the pipeline context within the new

on

functions in plugins? Do I simply not have to call

finish

and

proceed

anymore? Will ktor automatically detect that the request has already received a response and not pass it further down the pipeline?

Just updated to 2.0.0 and switched back to the CIO engine on all platforms. I immediately start seeing this error on Android.

Domain specific configurations require that hostname aware checkServerTrusted(X509Certificate[], String, String) is used

The SO answers I found say this function should not be used in this way. Is there a way to configure the CIO engine to avoid this method?

Does ktor 2.0 now support native websocket clients?

Hi! Client question: Is `HttpResponseValidator`'s

handleResponseException

supposed to also catch `io.ktor.client.call.NoTransformationFoundException`s? Cause it just seems to fall through in my case. I can see it catching other non-HTTP exceptions such as `kotlinx.serialization.MissingFieldException`s, for instance, and of course `io.ktor.client.features.ClientRequestException`s and `io.ktor.client.features.ServerResponseException`s. I'm on Ktor v1.6.7 on Android using the

CIO

engine.

Is anyone having trouble downloading the lib

com.github.nielsfalk:ktor-swagger:pom:v0.7.0

? I have this error

Could not find artifact com.github.nielsfalk:ktor-swagger:pom:v0.7.0 in maven-central (<https://repo1.maven.org/maven2>)

! I believe it may have changed repositories, I’ve been searching and haven’t found anything about a possible change

Hi, I use the ktor client (v1.6.7, jvm platform) with

HttpTimeout

feature ; I try to figure out were I can catch the

HttpRequestTimeoutException

thrown but I don't find any clean and generic solution. Here is my config :

val engine = TODO("CIO.create() or MockEngine")
val ktorBaseClient = HttpClient(engine) {
  install(HttpTimeout)
}
val ktorClient = ktorBaseClient.config {
		HttpResponseValidator {
			handleResponseException { t ->
				when (t) {
// -----> next line works with MockEngine but not with CIO.create()
					is HttpRequestTimeoutException -> throw MyCustomException()
					else -> throw t
				}
			}
			validateResponse { response ->
// it doesn't seem do by the right place to catch HttpRequestTimeoutException
				...
            }
        }
}

ktorClient.get("some_uri") {
  timeout { requestTimeoutMillis = 1.seconds.inWholeMilliseconds }
}

Note that to simulate a timeout via the MockEngine I do something like

MockEngine {
			delay(2.seconds.inWholeMilliseconds)
			throw IllegalStateException("should never be called")
		}

and it works, it throws a

MyCustomException

; but this is not the case in production code, with the CIO engine. Does someone have any advice or example ? thx for your help.

I've got a fun one on kotlin 1.6.20 and ktor 2.0.0 -

java.lang.IllegalStateException: FATAL ERROR: Could not find "io.ktor:ktor-http-cio"

- has anyone seen anything like this lately? Searching the slack I found an error in #apollo-kotlin but didn't get anywhere with that thread

Hey what is d/w Android and OkHttp in HttpClient in ktor?

Judging by the https://ktor.io/docs/default-request.html docs, I would think I was supposed to be in the scope of an

HttpRequestBuilder

when configuring

DefaultRequest

, but I'm instead in the scope of a

DefaultRequestBuilder

. AFAICT, they don't share the same structure. Previously, in ktor-client v1.6.7, I was able to access

body

inside of this builder scope, but no more. Docs:

val client = HttpClient(CIO) {
    defaultRequest {
        // this: HttpRequestBuilder
    }
}

Actual (ktor-client-core-jvm-2.0.0.jar):

public class DefaultRequest private constructor(private val block: DefaultRequestBuilder.() -> Unit) {

    public companion object Plugin : HttpClientPlugin<DefaultRequestBuilder, DefaultRequest> {
        // ...
    }

    // ...
}

// Hence:

defaultRequest {
    // this: io.ktor.client.plugins.DefaultRequest.DefaultRequestBuilder
}

Is this by design? Are the docs wrong here?

After upgrading Ktor to 2.0.0, I see this error in IntelliJ only (no error when building from gradle):

Cannot access class 'kotlinx.serialization.json.Json'. Check your module classpath for missing or conflicting dependencies

when I try to use content negotiation:

install(ContentNegotiation) {
        json(json)
    }

I checked the dependencies but I can't see any obvious conflicts.

im having an issue with single page application if i try to have it live any place but the root i get an error

routing() {
        singlePageApplication {
            applicationRoute = "/admin"
            useResources = true
            filesPath = "admin_app"
            }
}

when i try to set a route i get this

Admin_Dash_Compose.js:1          Failed to load resource: the server responded with a status of 404 (Not Found)

so i need to change my folder path to match or something? i tryed a few things but they didnt work out for me so far

Hi everyone, i need help with migration to 2.0.0 version. Now i have a crash in app start on IOS version 12.4.

dyld: Symbol not found: _OBJC_CLASS_$_NSURLSessionWebSocketMessage
  Referenced from: /Users/my name/Library/Developer/CoreSimulator/Devices/0B611991-66BF-4BE7-9534-628D49250D1E/data/Containers/Bundle/Application/E6ED3D75-FBF2-427E-8B82-F6E9E0B09D33/App.app/Frameworks/shared.framework/shared
  Expected in: /Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 12.4.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/Foundation.framework/Foundation
 in /Users/my user/Library/Developer/CoreSimulator/Devices/0B611991-66BF-4BE7-9534-628D49250D1E/data/Containers/Bundle/Application/E6ED3D75-FBF2-427E-8B82-F6E9E0B09D33/App.app/Frameworks/shared.framework/shared
dyld: launch, loading dependent libraries
DYLD_FRAMEWORK_PATH=/Users/denis.alexandrov/Library/Developer/Xcode/DerivedData/App-dljtddjulmigkpgpribvzgwhjcds/Build/Products/Debug-iphonesimulator
DYLD_FALLBACK_LIBRARY_PATH=/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 12.4.simruntime/Contents/Resources/RuntimeRoot/usr/lib
DYLD_ROOT_PATH=/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 12.4.simruntime/Contents/Resources/RuntimeRoot
DYLD_FALLBACK_FRAMEWORK_PATH=/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 12.4.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks
DYLD_INSERT_LIBRARIES=/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 12.4.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libBacktraceRecording.dylib:/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 12.4.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libMainThreadChecker.dylib:/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 12.4.simruntime/Contents/Resources/RuntimeRoot/Developer/Library
(lldb)

Hi. Trying to set timeout on KMM, For test purposes set a pretty small value and expect to receive a timeout exception. On Android I am capable to receive an error, but on iOS my request execute as usual. What am I missing?

internal fun defaultHttpClient(): HttpClient = HttpClient {
    install(HttpTimeout) {
        connectTimeoutMillis = 10
        requestTimeoutMillis = 10
    }
}

ktor 1.6.4

I don’t know if i put a link.. but.. https://kotlinlang.slack.com/archives/C0B8M7BUY/p1649824367818059

What is the minimum supported iOS version for ktor

2.0.0

? Ktor

2.0.0-beta-1

works on iOS 12, but

2.0.0

does not, it crashes with

dyld: Symbol not found: _OBJC_CLASS_$_NSURLSessionWebSocketMessage

I’ve tried both the Darwin engine and CIO.

What is the current status on Ktor supporting the Linux ARM targets? There hasn't been any news on this from the Kotlin/Ktor team since 14 May 2021 ( https://github.com/Kotlin/kotlinx.coroutines/issues/855#issuecomment-840552347 ).

Hello, I’m using ktor client (v1.6.8) and got this exception

java.io.EOFException: Failed to parse HTTP response: unexpected EOF

Can’t seem to understand further what happened but from my understanding it seems like it tried to parse the response payload but there wasn’t any.

Why is ktor not able to parse the res to a data class? I have the contentNegotiation plugin installed

client = HttpClient(CIO) {
            install(ContentNegotiation) {
                jackson()
            }
        }

Hi! I am currently migrating a project from Ktor-1.6.8/Kotlin-1.6.10 to Ktor-2.0.0/Kotlin-1.6.20 and something has changed with the ClassLoader-behavior: I cannot cast a received object from the (Apache-ActiveMQ-Artemis-)message-queue to the corresponding DTO anymore. In Ktor-1.6.8 an "OverridingClassLoader" was being used while in Ktor-2.0.0 it is "ClassLoader@AppClassLoader". How can I fix this to get rid of the ClassCastException?

Which is the recommended library for hashing passwords in Kotlin/Ktor? E.g. bcrypt does not appear to have an official Kotlin library.

I'm trying to use ktor 2.0 for a native app and getting an error:

Uncaught Kotlin exception: kotlin.native.IncorrectDereferenceException: Trying to access top level value not marked as @ThreadLocal or @SharedImmutable from non-main thread
    at kfun:kotlin.Throwable#<init>(kotlin.String?){} (0x43c461)
    at kfun:kotlin.Exception#<init>(kotlin.String?){} (0x435e6d)
    at kfun:kotlin.RuntimeException#<init>(kotlin.String?){} (0x43600d)
    at kfun:kotlin.native.IncorrectDereferenceException#<init>(kotlin.String){} (0x46606d)
    at ThrowIncorrectDereferenceException (0x483fbe)
    at CheckGlobalsAccessible (0x603112)
    at kfun:io.ktor.client.engine.curl.<get-curlApi>#internal (0x8b15c7)

Seems like this has come up in the past: https://github.com/ktorio/ktor/issues/1559 https://github.com/ktorio/ktor/pull/2193 Think I should file a new issue? Is there a known workaround?