it seems the

SinglePageAppRoutingHandler

and

ServerFilters.Cors

filter do not play nice together. The CORS OPTION request is being handled by

SinglePageAppRoutingHandler

. Since it doesn't match a resource, the

fallbackHandler

is used with a new GET request (without headers). When that request is handled by the Cors filter, the Origin header is missing causing the request to fail...

Hey guys, not sure if I'm missing something, but I ran into a weird issue with the Apache Backend. Setting up my server with

val server = DebuggingFilters.PrintRequest()
        .then(ServerFilters.CatchAll())
        .then(ServerFilters.RequestTracing())
        .then(CorsFilter)
        .then(PowerSocketSwitcherApp(powerSwitch, config.sockets))
        .asServer(SunHttp(9090))
        .start()

Will let me access it from inside the local network. But when I swap out SunHttp for Apache, I get a response "not authoritative". I just found that issue, but it's more centered around the work load it seems: https://github.com/http4k/http4k/issues/481 Btw, my CorsFilter:

val CorsFilter = ServerFilters.Cors(
        CorsPolicy(
            originPolicy = AllowAllOriginPolicy,
            headers = listOf("*"),
            methods = Method.values().toList(),
            credentials = false
        )
    )

Do you have any hints? Thanks in advance!

hi @Razvan I'm using Kondor with Http4k

is there a reason an example is not showing in OpenAPI for such definition (the content type is missing as well):

returning(Status.OK, Body.string(ContentType.TEXT_PLAIN).toLens() to "example string")

Hi, the docs pretty much say this isn’t possible, but just in case I’ve missed something, is there a way I can continue using typesafe routing (for dynamic path params) when using the

"/path/{param}"

pattern, or is this only possible for contract routes in the

"/path" / Path.uuid().of("param")

pattern? Here’s an example of the contract routing style, where http4k handles type-safety for the path parameter (n.b. using Result4k for error handling in these examples)…

fun getThingRoute(retriever: Retriever) =
   "/path" / Path.uuid().of("id") bindContract GET to { id ->
       {
           retriever(id)
               .map { Response(OK).body(it) }
               .mapFailure { it.toErrorResponse() }
               .get()
       }
   }

And the non-contract routing pattern I’d like to switch to, but which I think needs our own typesafe error handling (if we want to handle non-UUID path parameters, for example)...

fun getThingRoute(retriever: Retriever) =
   "/path/{id}-something-after-param" bind GET to { request ->
       resultFrom { UUID.fromString(request.path("id")) }
           .mapFailure { NotFound("ID must be a valid UUID") }
           .flatMap { id ->
               retriever(id)
                   .map { Response(OK).body(it) }
           }
           .mapFailure { it.toErrorResponse() }
           .get()
   }

Thanks!

Are there any dropwizard admin like plugins for http4k? I'm trying to make a dropwizard app go away, but the main reason for DW is the http admin server that allows for heap-dumps, thread-dumps etc. Is there anything like that already existing?

I guess we’ll have to test it to see the impact in http4k-graphql…

It's strage that kotlin does not catch it as Java's

getResourceAsStream

is annotated as

@nullable

I thought it would say that you can't call

.reader()' on its result without

?

or

!!`

Companion::class.java.getResourceAsStream("/${resource.removePrefix("/")}").reader()

Hey guys, I am introducing http4k in a project at work and I somehow get an error when serializing with Jackson in my http client:

java.lang.NoSuchMethodError: com.fasterxml.jackson.module.kotlin.KotlinModule

I am using versio

2.10.2

of

com.fasterxml.jaclson.module

and version

4.8.0.0

of http4k. How can I fix this?

@fredrik.nordin I've stripped out the refreshVersions plugin for the moment so you should be able to build from master again. Hopefully we'll be able to put it back in soon because it's really useful.

Hi, I'm looking to some lib to replace crude shell commands such as

curl -X GET -H "Authorization: token $token <https://api.github.com/repos/kotlin-graphics/mary/contents/$path>

I also need to parse the responding json to extract, for example, a sha encoding and create some other json to pass to some other

curl

commands. Can http4k be all I need? 😛

When I use http4k-contract to generate a spec, the path and query descriptions are serialized as

null

with both Argo and Jackson. The Swagger Editor seems to treat these as warnings, Swagger UI works fine, but the latest Redoc throws an exception that prevents the UI from loading. Is there any way to set a non-null description for these parameters? Or has anyone had a better experience with a different version of redoc?

Have you declared

mavenCentral()

as a repo for plugin dependencies?

I was wondering thought, if there might be an interest of a http4k module to interface with the github api. All the current solutions don't work if you don't have the repo cloned, as far as I got

Really looking forward to watching you guys on the official Kotlin YouTube channel!

Hello! I’ve been playing with the OpenTelemetry module for the Tracing filters and wanted to have an easy way to name the server spans for each different route. Rather than pass a spanNamer – which would have the effect of having my naming logic separated from the routing definition, I extended the routing DSL a little bit to get this:

fun endpoints() = "/orders" bind POST to routes(
            "/create" bind ::createOrder named "Create Order",
            "/submit" bind ::submitOrder named "Submit Order",
    )

object SpanNameFilter {
    operator fun invoke(name: String) = Filter { next ->
        { req ->
            Span.current().updateName(name)
            next(req)
        }
    }
}

infix fun RoutingHttpHandler.named(name: String) = SpanNameFilter(name).then(this)

Wondered if this might be something you’d be interested in adding to the opentelemetry module in some form or other? Or is there a different way of doing this you’d recommend? Would a more general ability to name RoutingHttpHandlers be useful?

Hi guys! i fell in love with http4k for its simplicity. Now i am looking for a dependency injection solution for it. Koin seems to be the kool kid in school right now. However i hardly find anyone talking about it in the context of backend/server side of things. i feel like Koin has similar philosophies as http4k has (simplicitly, explicit over implicit, no magic) and might be a good fit here. Code generation things like dagger i do not really like and these sorts of things were the reason why i even started moving away from spring boot/java stack. what are you guys using?

Hey guys! When working with http4k, I noticed something that “worried” me a bit. I saw that the class

UriTemplate

was proposing an extension function on

String

called

trimSlashes

. What is the reason to declare an extension function on the class String? This extension function will be accessible anywhere in your code base for any String you want, however it is very clear that it should only be used for `String`s representing URI`s . I was curious behind the reason on declaring it on

String

and not

UriTemplate

for instance.

A quick reminder that this coming Tuesday @ 1700BST @s4nchez and I will be presenting a JetBrains Webinar on your favourite http toolkit. We'll be live coding an app and showing the different runtime options (server/aws/Graal). Details and sign-up here: https://info.jetbrains.com/kotlin-webinar-june-15-2021.html

Hello guys, we are trying out the RateLimit functionality and we can’t get it work as we expected. Here is how we set up the client:

private fun client(uri: Uri): HttpHandler =
    SetBaseUriFrom(uri)
        .then(RateLimit())
        .then(OkHttp(okHttpClient(100)))

Note: It’s using the default RateLimitConfig which is documented as

By default, handles maximum of 50 requests per 5 seconds.

Here is how we are testing this out:

fun main(){
    val timeTaken = measureTimeMillis {
        makeMultipleRequests(51, client(Uri.of("<http://localhost:3002/some-url>")))
    }
    println(timeTaken)
}

I would expect the time taken to be greater than 5 seconds? Is this is how it’s suppose to work? Running it a few times to get an average it seems to complete in around 2-3 seconds. Thanks in advance

Does the following make sense? The JSON lens is typed as non-nullable

X

yet gives out a

null

pointer

public fun main() {
    val l: BiDiBodyLens<X> = Body.auto<X>().toLens()
    val request: Request = Request(POST, "/").body("null")
    val extracted: X = l.extract(request)
    print(extracted) // null :shrug:
}

The video is now published oh the webinar. Any question or comments about thuhgs that didn't make any sense (it all went past at 100mph), please let us know:

Hi, got an issue that I can’t figure out. I made a lib based on http4k that exposes a method that calls a url using OkHttp client. When I use it from a http4k client app I have no problem, but I also tried to use it from a SpringBoot (kotlin) project and I get this error:

Companion
java.lang.NoSuchFieldError: Companion
	at org.http4k.client.OkHttpKt.requestBody(OkHttp.kt:75)
	at org.http4k.client.OkHttpKt.asOkHttp(OkHttp.kt:68)
	at org.http4k.client.OkHttpKt.access$asOkHttp(OkHttp.kt:1)
	at org.http4k.client.OkHttp$invoke$1.invoke(OkHttp.kt:38)
	at org.http4k.client.OkHttp$invoke$1.invoke(OkHttp.kt:35)

It’s the basic client, nothing fancy

OkHtttp()

if I replace that with JavaHttpClient() or ApacheClient() all works. Does that ring a bel or should try to make test projects to show it ? The error line is the if line in this function

private fun Request.requestBody() =
    if (permitsRequestBody(method.toString())) body.payload.array().toRequestBody()
    else null

Hi 🙂 Does anyone here know if there is something existing for http4k to do Digest Authentication (https://en.wikipedia.org/wiki/Digest_access_authentication) with a client in http4k? 🙂

Well, we promised a bit more JetBrains'y /http4k goodness and here it is. In the new episode of Talking Kotlin, we chat with the JB guys about the what, the why and the how of http4k.

Hello, anyone played enough with SSE to have an idea how to resolve a CORS error ? the browser error is:

logs.html:1 Access to resource at '<http://localhost:8080/logsse>' from origin '<http://localhost:8880>' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Couldn't figure out how to set that header...

is there a recommendation what http4k backend to use?

hi, how do I customize Jackson for openapi generation? serializing "description": null seems illegal in many cases

Is it possible to add an openAPI descriptions to my domain objects? (e.g here https://github.com/http4k/http4k-by-example/blob/master/src/main/kotlin/verysecuresystems/domain.kt)