kotlinlang #ktor

Hi guys, I'm trying to create a simple logging Feature around client calls (using Apache as engine) I looked into JsonFeature and HttpPlainText as inspiration, and managed to log output requests bodies (if present) and input responses. But, logging the responses consumes the stream, and I have no clue about how to write again the raw content to the response, for the following features (such as Json serialization..) as the HttpResponse.content is a ByteReadChannel (so readonly..)

lukaswelte

10/25/2018, 2:40 PM

I’m using ktor 0.9.5's CIO HttpClient to make HTTP calls to other services (so ktor server receives http requests and makes an http request to other services). On my local machine, the http request responds like it should. But on AWS (where it worked with 0.9.3) it never returns. Does somebody have an idea where the problem might be?

jcechace

10/25/2018, 4:13 PM

How should I get more info from a ktor-client error, other than this?

io.ktor.client.features.BadResponseStatus: null

client.put<Unit>{
            url("<http://host.com/apis>")
            contentType(ContentType.Application.Json)
            body = "{}"
        }

Dias

10/25/2018, 4:45 PM

and if there was a problem with certs I guess exception would have been thrown here

requireNotNull(getKey(sslKeyAlias, sslPrivateKeyPassword.toCharArray()) == null) {
                    "The specified key $sslKeyAlias doesn't exist in the key store $sslKeyStorePath"
                }

in CommandLine.kt, but it hasn't been thrown

Dias

10/26/2018, 9:20 AM

I haven't touched lambda in a while, but does it really give you an http request to work with? Does it not just invoke function that you specify with some data passed in?

NGupta

10/26/2018, 9:38 AM

Hi guys, I am facing a strange issue with Ktor HttpClient(CIO). The client call looks like below: httpClient.get<HttpResponse> { method = HttpMethod.Get url("http://10.1.1.1") } It is expected to throw an error initially, I am catching that and recalling it after a delay. If I reinstantiate the client -> httpClient = HttpClient(CIO) in the catch block, it works fine. If I don't it stays as is forever, and never comes up with a response. Any help is appreciated

NGupta

10/26/2018, 9:47 AM

More to the point: This does not work: while (condition) { try { httpStatusCode = httpClient.get<HttpResponse> { method = HttpMethod.Get url("ActualURL") }.status.value } catch (exception: ConnectException) { delay(ppsConstant.delayTimeIntervalInSecondsForHealthCheck, TimeUnit.SECONDS) } } This works: while (condition) { try { httpStatusCode = httpClient.get<HttpResponse> { method = HttpMethod.Get url("ActualURL") }.status.value } catch (exception: ConnectException) { httpClient = HttpClient(CIO) delay(ppsConstant.delayTimeIntervalInSecondsForHealthCheck, TimeUnit.SECONDS) } }

bootstraponline

10/26/2018, 2:11 PM

https://github.com/ktorio/ktor/issues/678

Kevin

10/26/2018, 8:50 PM

I recently tried out Ktor. One thing I found difficult was the examples all use wildcard imports. And so when I was making my own project I chose not to wildcard import which is super tricky since the DSL brings in extension methods from all over the place and if you miss one you get a non helpful error message. Is the expected usage that I'm going to wildcard import all of the ktor stuff?

👍 1

orangy

10/26/2018, 9:05 PM

Multiconfiguration is covered by the HOCON itself, please check the docs: https://github.com/lightbend/config

coletz

10/27/2018, 12:38 PM

There's no built in logging capability on ktor client AFAIK. It was discussed some day ago. Seems like the best option is to use a mock client as a pass-through iirc, I'll try to find out the message

jdemeulenaere

10/27/2018, 5:17 PM

Is receiving a ByteArray from HTTP call with Ktor JS implemented ? Sending works fine, but when the server responds with another byte array an error is thrown :

No transformation found: class JsHttpResponse -> class null

Robert Menke

10/28/2018, 12:35 AM

@orangy For example in the node ecosystem Express has been a foundation that other frameworks have built on top of it. Examples: - https://docs.nestjs.com/ - https://feathersjs.com/ - https://sailsjs.com/ - https://adonisjs.com/ One of the awesome things about Ktor is that its design is very modular, and I’m wondering if people are building frameworks on top of Ktor that are more opinionated about architecture, design patterns, 3rd party libs, etc.

claudiug

10/28/2018, 6:33 PM

good evening(berlin time). Does anyone try graal with native-image and ktor?

spierce7

10/28/2018, 7:21 PM

Why isn't there a

io.ktor:ktor-client-json-js

? Is there a way to use kotlinx.serialization with ktor?

Narayan Iyer

10/29/2018, 12:50 PM

Any success implementing a

JSON

response with KTOR? Tried and got this:

java.lang.IllegalArgumentException: Response pipeline couldn't transform 'class java.util.Collections$SingletonMap' to the OutgoingContent
	at io.ktor.server.engine.BaseApplicationResponse$$special$$inlined$apply$lambda$1.invokeSuspend(BaseApplicationResponse.kt:38)
	at io.ktor.server.engine.BaseApplicationResponse$$special$$inlined$apply$lambda$1.invoke(BaseApplicationResponse.kt)
	at io.ktor.util.pipeline.PipelineContext.proceed(PipelineContext.kt:53)
	at io.ktor.util.pipeline.Pipeline.execute(Pipeline.kt:24)

Checked out the documentation and saw this:

install(ContentNegotiation)

... but documentation is sketchy ... any ideas?

10/29/2018, 1:38 PM

When writing a ktor feature, under what circumstances should the feature add a phase vs reusing an existing one?

dimsuz

10/29/2018, 5:12 PM

Hi! I generated Ktor project using generator on ktor.io, then upgraded it to

1.0.0-beta-3

and kotlin

1.3.0

, but I cant run the server. I try this:

$ ./gradlew run

> Task :run FAILED
Exception in thread "main" java.lang.IllegalArgumentException: Neither port nor sslPort specified. Use command line options -port/-sslPort or configure connectors in application.conf
        at io.ktor.server.engine.CommandLineKt$commandLineEnvironment$environment$1.invoke(CommandLine.kt:121)
        at io.ktor.server.engine.CommandLineKt$commandLineEnvironment$environment$1.invoke(CommandLine.kt)
        at io.ktor.server.engine.ApplicationEngineEnvironmentBuilder.build(ApplicationEngineEnvironment.kt:95)
        at io.ktor.server.engine.ApplicationEngineEnvironmentKt.applicationEngineEnvironment(ApplicationEngineEnvironment.kt:40)
        at io.ktor.server.engine.CommandLineKt.commandLineEnvironment(CommandLine.kt:50)
        at io.ktor.server.netty.EngineMain.main(EngineMain.kt:16)

Although I have perfectly valid port in `resources/application.conf`:

ktor {
    deployment {
        port =  8080
    }
    application {
        modules = [ com.example.ApplicationKt.module ]
    }
}

What am I doing wrong?

📝 1

✅ 1

10/29/2018, 5:39 PM

In the

SimplifiedSessionStorage

example on https://ktor.io/servers/features/sessions/storages.html, what is the (not shown)

getCoroutineContext()

supposed to do in practice? Also that form of

reader()

is deprecated now --

CoroutineScope.reader

is probably what it should be, but on what scope?

✅ 1

📝 1

Jonas Bark

10/29/2018, 5:48 PM

I'm trying the new ktor-client-json-js but getting the following error: "NoTransformationFound: No transformation found: class JsHttpResponse -> class StartPage at Coroutine$receive_jo9acv$.doResume (http://127.0.0.1:8080/lib/ktor-client-core-js.js:1240:21) I'm installing the JsonFeature like this:

install(JsonFeature) {

            serializer = KotlinxSerializer().apply {
                register(StartPage.serializer())
            }
        }

The same code works just fine on iOS & Android Am I missing something here?

Jonathan

10/30/2018, 8:57 AM

Hi there. Is there a simple way to use grpc with ktor?

RobinVdB

10/30/2018, 12:24 PM

Do you guys recommend ktor as a backend for a websocket server for a simple chat service (for college) I allready use ktor daily for REST apis

functionaldude

10/30/2018, 2:25 PM

Hi! I’m currently migrating one of my ktor (version

0.9.5

) project to Kotlin

1.3.0

, but somehow this seems unsupported. Im using the new

kotlinx-coroutines-core

(version

1.0.0

) but ktor still uses the older version, where many functions and classes are in the experimental package, therefore I always get a

NoClassDefFoundError

. Do you have any suggestions how to fix this? Or do I need to update ktor to

1.0.0-beta3

orangy

10/31/2018, 9:30 AM

We plan to pay special attention to performance, but any bugs have higher priority, i.e. “Works, then Fast”. Otherwise we consider it Feature Complete for 1.0, and any additional features will come in the following releases.

👍 5

Saša Šijak

10/31/2018, 2:08 PM

and there is 8080 port set in the application.conf

✅ 1

sannysoft

10/31/2018, 2:32 PM

Hello. Anybody faced the issue with location deprecation problem? https://github.com/ktorio/ktor/issues/688

📝 1

✅ 1

napperley

11/01/2018, 12:48 AM

Many exceptions are being thrown around reflection when using Zulu JDK 11. The server appears to run ok without any issues so far.

app.log

Hamza

11/01/2018, 5:49 AM

is there a way to get the ip from the request? I tried printing the headers, and I don't think any of these are the IP from the request

-.txt

✅ 1

Saša Šijak

11/01/2018, 6:04 AM

How do you guys compare developer experience of ktor compared to spring boot? I am planning to start a new personal project soon and am evaluating ktor. As far as I saw from my small research, web layer is covered pretty well and for other parts you can pick and choose with a bit of plumbing (don`t have autoconfiguration like with spring boot for almost everything). I would like to try such approach again because when you have experience and know what you are doing you have better control of your app and you will not turn it into a spaghetti monster. Benefits that I see are that the code is easier to reason about and debug, there is less magic (no reflection and autoconfiguration) and the app is so much faster to start (this is a big for me currently, I`m tired of waiting 30s for a larger spring boot app to start on my macbook pro). Has anybody done apps in both spring boot and ktor and can provide some insight?

Title

Saša Šijak

11/01/2018, 6:04 AM

sannysoft

11/01/2018, 8:27 AM

Spring Boot is definitely more stable but as for me quite overcomplciated. I like Ktor, but at the moment there still might be some minor bugs and what I don’t like much is Locations module and creating routes via Route functions (that should be added to route list manually). This part is way more beautiful in Spring with it’s controllers and annotations.

kenkyee

11/01/2018, 10:21 AM

What does the larger boot app use for features? Simple boot apps don't take that long. I'd make sure whatever framework you try has support for what you need.

Saša Šijak

11/01/2018, 11:11 AM

@sannysoft Spring Boot is actually adding a way to define the routes as in ktor. I like that way, you have more control, can test easier and is not constrained by annotations

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