Hi everyone 🙋‍♂️ I have Ktor microservices and consuming the APIs in KMM. Which one do you prefer? 1- Microservices communication to each other through HttpClients and return the response to KMM • (What about authentication between services? Shouldn’t it be with the user token? It’s also painful to transfer the token) • BTW I use consul for the service discovery and services are running in the same instance for now :) 2- Make async calls directly to each API and return the response to the clients in KMM Any suggestions? Thanks in advance!

Hi 👋 is anyone aware of any libraries for ktor that handle REST-related concerns like generating documentation/specs, versioning of APIs, HATEOAS-support, ...? I know there are such projects for e.g. Spring, but haven't found anything for ktor.

Anyone know if there is a way to run the kotlin code formatter that Intellij uses from the command line

it would be nice to be able to format the projects code from gradle or as a git hook when checking in, just wondering if anyone is doing this, I know you can use ktlint but looking for something that would use the same format as the intellij formatter, merry Christmas everyone 🎅

I want to filter out the courses on the basis of match query to the courseTitle. So How can I perform this operation via KMONGO at server side ? This is my Course Data Class And I have a course document in MongoDB compass. @Serializable data class Course( @BsonId var id: String = ObjectId().toString(), val courseTitle: String, val imageUrl: String, val description: String, val noOfStudentEnrolled: Int, val course_teacher : Teacher, var noOfLessons: Int, val noOfStudentRated: Int, val rating: Double, val tag: String? = null, val lessons: List<Lesson>, val time: String, )

hello... Merry Christmas and Happy New Year... does anyone has any experience with Spring Security? I added the dependency of spring-security into the project, logged in with the generated password, i can access all the pages using their links directly. but there is one page that I still can access but I can't use its form with

POST

function, i get the 403 error, why this is happening?

Are my serverless Kotlin options (for aws lambda, for instance), still SpringBoot or Micronaut?

Hello K friends, What if Node were more than just JS? To celebrate the new year, I am pleased to share a new project called Elide, a new server runtime, like Node or Deno, but polyglot, written in Kotlin and based on GraalVM. We are in alpha and very open to early feedback and contributions for anyone interested, over in #framework-elide 🥳 You can do wild things with it, like fast React SSR in Micronaut or Spring. Guest language support is starting with JS, but there are plans to integrate other languages like Python, Ruby, and Rust/Go/etc. via LLVM. Of course,

native-image

is supported out of the box. • 🚀 Trying it out

curl -sSL --tlsv1.2 dl.elide.dev/cli/install.sh | bash -s -

👆 the one liner works on Darwin (amd64/arm64), and Linux (amd64) so far.

If you prefer NPX:

npx @elide-dev/elide@alpha shell

K Building Kotlin apps with it • Elide can be used as a plain library with a regular Micronaut server, and Ktor support is on the way. There are Maven artifacts in a custom repository which is easy to use during the alpha; you can see a sample here. • G Gradle plugin You can easily install the Gradle plugin to build your frontend assets and your Kotlin/JS, and package it into your server binary. It will handle building for SSR and CSR both, so you can easily switch between browser rendering modes. Check it out here. Maven and Bazel support are planned. • 🖥️ Using the shell

elide shell

drops you into a shell just like Node (see attached screenshot), the difference being the

URL

class we're using here is implemented in Kotlin, backed by the road-tested power of Micronaut, KotlinX, Netty, and the Java standard library. It has simply been adapted for use in JavaScript, according to the WhatWG URL Spec. • js Use Kotlin/JS or regular Node stack Elide packages and consumes your JS/TS with built-in support for

esbuild

, so you can use a standard Node toolchain or the Kotlin/JS stack. • 💨 Super fast React SSR Because Elide is basically Kotlin with a super-fast JS runtime attached, it can do JS SSR without leaving the JVM. This can soon be drop-in compatible with many React apps. You can see a live sample here to confirm it is fast and server-rendered. The code for that sample is pasted below to show how simple it is to call back and forth between Kotlin and your React app:

@Page class Index : PageWithProps<YourProps>(YourProps.serializer()) {

    // Serve React SSR.
    @Get("/") suspend fun indexPage(request: HttpRequest<*>) = ssr(request) {    // 1: tell the server we're going to do SSR for this request
      head {
        title { +"Hello, Elide!" }
        stylesheet("/styles/base.css")
        stylesheet("/styles/main.css")
        script("/scripts/ui.js", defer = true)   // <-- 2: serve the CSR bundle so it can hydrate the react SSR response
      }
      body {
        injectSSR(this@Index, request)    // <-- 3: execute the JS VM to produce the SSR response, and splice it into the server response
      }
    }

}

• 🐙 Contributors needed The future of software is much more polyglot than today's paradigm: developers love to fight about frameworks, but at the end of the day, we're all writing code, and eliminating barriers between languages means easier collaboration and more value for all of us. It shouldn't be a Node vs. The World or a Rust vs. The World argument; we should get to pick and pull the best code we want from anywhere and use it to build our apps, especially from a multi-platform language like Kotlin. This runtime and framework are designed for that future. *If you agree, join us and make a dent in the universe*; you'll have a chance to be impactful and shape a brave new idea from the ground up. • 🙏 Thank you We chose Kotlin because of the fantastic community. 2023 will be a massive year for Kotlin, and we think that betting the farm on it is reasonable and smart. We are super excited about what JetBrains and Kotlin have in store for us with K2, context receivers, value classes... just so much to look forward to. Cheers and happy new year, Kotlin devs, K sam Slack Conversation

This message was deleted.

Anyone here from the Kotlin team has any update of this BUG: Reflection: Blockhound detects a blocking call from kotlin-reflect in Spring Boot application I think would be nice to have some feedback about this issue.

Hi I wanted to use Kotlin for backend services. There are bunch of frameworks for server side. Most famous ones are Springboot, spring and Ktor. My server would be mostly IO bound. Also, another concern is currently my org uses REST but we might switch to GRPC later. I want something which might require minimal effort If I change the transport layer.

Hey guys, anyone had this issue?

2023-01-07 00:12:00.230 [qtp1706939736-20] WARN  o.eclipse.jetty.server.HttpChannel MDC= - handleException /reference/api/swagger.json com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Joda date/time type org.joda.time.DateTime not supported by default: add Module "com.fasterxml.jackson.datatype:jackson-datatype-joda" to enable handling

Http4k & Open api

Hey everyone, I’m working on my first Ktor project and I have noticed that I can have routes handling separated in multiple files (e.g. auth, users, settings, etc) using

routing

, but when working with request validation I can’t separate the validations in multiple files. I’m thinking to make that every server feature is isolated module and I’m not sure how to break the validations apart per module. Any ideas how to proceed? Thanks

hello.... is there a dependency for

org.springframework.security.core.context.DeferredSecurityContext

Hey team. We were trying to write an automatic retry on 5xx when using the ReactiveAuthenticationManager, with authentication handled via an API call. We came up with something like this to override the

authenticate

with. Do you people see any potential issues with it ?

class ServiceException(message: String?, var statusCode: Int) : RuntimeException(message) {
    init {
      statusCode = statusCode
    }
  }
  
fun doAsyncAuthentication(
    url: HttpUrl,
  ): Mono<Authentication> {
    return webClient
      .post()
      .uri(url.toUri())
      .body(BodyInserters.fromFormData("token", "tokenValue"))
      .retrieve()
      .onStatus(HttpStatus::is4xxClientError) { response ->
        response
          .createException()
          .map { InvalidBearerTokenException(it) }
      }
      .onStatus(HttpStatus::is5xxServerError) { response ->
        Mono.error(ServiceException("Server error", response.rawStatusCode()))
      }
      .bodyToMono<TokenInfoResponse>()
      .retryWhen(Retry
        .backoff(3, Duration.ofSeconds(1))
        .filter { throwable -> throwable is ServiceException })
      .map {
        OurAuthenticationResponse(it.clientId, it.scopes)
      }
  }

hi guys

quick question is this a good place to ask about springboot cors configuration? i am trying to upgrade my corsConfig https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.7-Release-Notes https://spring.io/blog/2022/02/21/spring-security-without-the-websecurityconfigureradapter I updated my config as such

@Configuration
@EnableWebSecurity
open class CorsConfig{

  @Bean
  open fun springSecurityFilterChain(http: HttpSecurity): SecurityFilterChain {
    http
      .cors()
      .and()
      .csrf().disable()
    return http.build()
  }

  @Bean
  open fun corsConfigurationSource(): CorsConfigurationSource {
    val configuration = CorsConfiguration()
    configuration.allowedOrigins = listOf("*")
    configuration.allowedMethods = listOf("*")
    configuration.allowedHeaders = listOf("*")
    val source = UrlBasedCorsConfigurationSource()
    source.registerCorsConfiguration("/**", configuration)
    return source
  }
}

but application starts properly but when i call the base endpoint i get a 500 error and i dont know where to go to debug please advice

https://stackoverflow.com/q/75098802/10334333 Could someone answer me this question

I am having one problem with my IDE and kotlin.

Cannot inline bytecode built with JVM target 11 into bytecode that is being built with JVM target 1.8. Please specify proper '-jvm-target' option

I am using kgraphql in ktor but I am seeing this problem. Not sure how to fix it.

What are some of the orms worth looking into? Looking to improve our interfacing with a postgres database on a server side jvm application. Ty!

looking at the Kotlin DSL for Spring Security filter chains, it seems that there is no way to configure a UserDetailsService for a SecurityFilterChain anymore; what's the recommended workaround? I'm using 2 filter chains that protect different routes and use different users; 1 for actuator and 1 for the API

task

stage

fails with error for full-stack-app tutorial https://github.com/kotlin-hands-on/jvm-js-fullstack/blob/b4bebe15f848a028d2dac6a8faff0e0fe8473a13/build.gradle.kts#L111

Execution failed for task ':installDist'.
> Entry lib/shoppinglist-1.0-SNAPSHOT.jar is a duplicate but no duplicate handling strategy has been set.

adding this in build.gradle doesn’t help

tasks.withType<Copy> {
    duplicatesStrategy = DuplicatesStrategy.INCLUDE
}

Could somebody help me? 🙂

Hi all, I am looking for a freelance Kotlin developer to build a GraphQL api using Quarkus. Please DM me if you're interested.

Does anyone else run into issues with getting Detekt / Spotless (with ktfmtt) / Intellij Ktfmt plugin/ and the intellij formatting to all agree? I’m running into a lot of thrashing at work, even after trying to make sure they are all standardized on ktfmt with google style (and copy pasting the editorconfig for google style from the ktfmt repo). I’m thinking of trying out ktlint instead. Anyone have similar experiences with ktfmt (or not have these problems at all with a different formatter?)

Is this supposed to be used on JVM, or only in JS? (The docs are a bit confusing.) https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.js/-promise/

Hi everyone! I'm looking to implement a long-living server stream with gRPC that clients can subscribe to. Context: there is a group of users with users and a lead user, when the lead starts and action

performAction()

which is a unary RPC. I want to notify the other users with information about that action. I would expect those members to be subscribed to another long-living RPC that facilitates sending that information. Do you have any examples of how can achieve that in Kotlin? I was looking into something like: https://dev.bitolog.com/grpc-long-lived-streaming/ https://sultanov.dev/blog/grpc-long-lived-streaming-using-observer-pattern/ But those implementations are written in Go and Java, and I'm struggling to find examples in Kotlin

what coroutine-aware profilers are there? I know of DebugProbes but have not seen any tooling except that. Also found some coroutine support in JProfiler. I have a server-side app that has mixed execution where some of the code is run via the default dispatchers and some is executed outside of coroutines, on plain jvm threads. How would I create a flame graph? (maybe one for the thread perspective and one for the coroutine perspective?)

Guys I’im using Ktor for a Grade System where Authorisations have bin encapsulated in token/ I have endpoint that only people with specific authorisation can are allowed What’s the best practice to combine these authorisation ?

authenticate(AuthorizeFor.ManageCourse, AuthorizeFor.ManageSubject){
     post("/enroll-student") {...}
}

Is this ok ?

authenticate(AuthorizeFor.ManageCourse, AuthorizeFor.ManageSubject,AuthorizeFor.ManagePauta,AuthorizeFor.ManageBatch,AuthorizeFor.ManageAdmin)

Hello Everyone, I have a question regarding MDC and Ktor. We are currently using the

CallLogging

plugin to inject MDC values in the pipeline like so:

fun Application.module() {
  install(CallLogging) {
		mdc("clientIpAddress") { call ->
      call.request.header("X-Forwarded-For") ?: "UNDEFINED"
    }
  }
}

We are generating a

userId

within the route which needs to be added to MDC such that it is available outside the current co-routine context:

fun Application.myRoutes() {
  routing {
    get("/testMDC") {
	 	MDC.putClosable("userId", "${UUID.randomUUID()}") // <-- This is thread local and does not carry onto other co-routines
    }
  }
}

The

clientIpAddress

works fine and is logged throughout but

userId

only logs in local context. Is there any work around for this?

Hello. I have a ktor route that calls a simple business function to process data. The Route is responsible for receiving data from the body and passing it to the business function, and for formatting the returned values. Like so:

get("/some/uri") {
  val data = call.receive<SomeType>()
  val result = doBusinessStuffWith(data)
  call.respond(result.doSomeFormatting()
}

And the business function is defined somewhere else:

fun doBusinessStuffWith(data: SomeType): SomeReturnType {
...
}

Is there a way to test the controller in isolation by mocking the business function

doBusinessStuffWith

? In Javascript, you can mock any function call with

jest

. I assume, it is not that easy in kotlin, but is there a nice way? Thank you for your ideas …