@RichyHBM here's the deck: https://speakerdeck.com/daviddenton/server-as-a-function-in-kotlin still no sign of the video - think that'll be a few weeks as they edit them together

hi, we were recommended by our OPs to expose our metrics on a different port from our app’s main HTTP server. I wonder if there is a way in http4k do so, ie expose a RoutingHttpHandler on a different port from the app?

@natpryce how complicated does it need to be?

@RichyHBM upgrading (to 1.3) in version 3.96.0 is on it's way.

@Xavier Hanin that's awesome! hope it went well. Even though my french is appalling, I'll be watching this... 🙂

hi @dave, would you mind to share some code to illustrate it? We got it working, but we fear it is not idiomatic. BTW, we registered com.fasterxml.jackson.datatype.joda.JodaModule

@David Hamilton you can easily mount an http4k app alongside another servlet using the HttpHandler.asServlet() extension function. If you look at the

Jetty

object you can see the pattern for how this can be done using an embedded Jetty backend

@David Hamilton Here's an example of how to combine list of filters in a functional fashion:

val defaultStack = Filter.NoOp.then(ClientFilters.GZip())

    val additionalFilters: List<Filter> = listOf(
        DebuggingFilters.PrintRequestAndResponse(),
        ClientFilters.BasicAuth("user", "pass"))

    // additional after default
    val combinedFilter1: Filter = additionalFilters.fold(defaultStack) { acc, next -> acc.then(next) }
    
    // additional before default
    val combinedFilter2: Filter = additionalFilters.fold(Filter.NoOp) { acc, next -> acc.then(next) }.then(defaultStack)

you'd end up with

{
  "in": "body",
  "name": "body",
  "required": true,
  "schema": {
    "$ref": "#/definitions/someOtherDefinitionId"
  },
  "description": "the body of the message"
}

@xuemin.guan easiest thing is to compose 2 modules together (each with a different root context).

@dave @s4nchez Huge kudos to both of you for adding the

cloudnative

module! Looks great and exactly what was needed for http4k to be a real contender for writing all my k8s hosted services 👏

@xuemin.guan are you able to send the headers the server is sending back? My first guess is that you have the filter being applied twice, hence duplicating the header, but it's hard to tell without looking at how things are setup on you side.

just curious, is there a filter similar to

RequestTracing

but using Opencensus?

Hi everyone, is there a way to stream body payload on the server side, or at least restrict its size to a same limit without reading it into memory?

Hi, I read that http4k can generate JSON Schema models (https://www.http4k.org/guide/modules/contracts/) ...is there an example/tutorial for that?

but it's possibly pretty expensive way to operate without a discriminating value

Hi http4k! Is it possible to have optional path segment? Like:

"/bar/" / Path.string().of(name = "foo")

comes

"/bar/" / Path.string().of(name = "foo").optional

So it would match both

/bar/foo

and

/bar/

I am looking at the nonblocking, but I am not sure how to test this. according to https://www.http4k.org/cookbook/websockets/ you can do

testApp.testWsClient

but I need something like

testApp.testWebsocket

this was missing from the docs - I'll stick this example on the site later

I wanted to mention ( as most comments tend to be focused on issues/problems rather then whats NOT a problem) I find the entire http4k project quite exemplary in both function and style/form. At first glance (long time ago) my impression was that it must be deficient because the the code-base was too small and the style - simple and elegant -- to the point I was skeptical it would actually work in 'the real world' I have verified to my satisfaction that I was totally wrong. The apparent simplicity is actually elegance -- a direct representative of the overall design architecture. So much so that I still have a hard time figuring out how to use it -- it is so different form 'conventional' style/architecture that my instincts of where and what to look for are worthless I dont know what to suggest or how exactly to improve that -- just a comment that it is difficult to grasp how to use the various pieces and how they fit together -- because it was designed and implemented so well -- but differently -- I will speculate many people have a hard time 'Seeing the Obvious' -- I do ... but when I do -- its worth it> So thank you -- not just for a great library but also an inspiration and example of excellent engineering we could all strive to follow as a model of something done well.

So we’d need the body lens to use a mapper configured specifically for the route, not for the whole application

What animal would you want on the cover?

@Xavier Hanin thanks for posting that. I'll take a look and see if we can merge that method into the Jackson module.

@Xavier Hanin I've released v3.111.0 to maven with the view support in it. You can use the following form to create a lens with the view:

Body.autoView<ArbObjectWithView, Public>().toLens()

@Xavier Hanin Np. Thanks for the PR! Although lets not belittle my effort of typing

release.sh 3.112.2

Hello Everyone. I am trying Http4k for a project. Have a doubt in my mind which I couldn't find in docs. 1. How is blocking code handled in Http4k. 2. What's the relation b/w a request and thread when I am using Netty. 3. Is there a construct provided by the http4k to execute asynchronous blocking and non-blocking calls.

Hey peeps. Bit of an FYI about an API change. As a part of

v3.116.0

that we've just released, we've introduced a better API for

http4k-contract

which is more consistent with the way we define

route

meta. It looks like this:

val router = "/basepath" bind contract {
    renderer = SimpleJson(Jackson)
    descriptionPath = "/swagger.json"
    security = ApiKey(Query.required("the_api_key"), { true })
    routes += "/descriptions" meta {
        summary = "endpoint"
        description = "some rambling description of what this thing actually does"
        operationId = "echoMessage"
        tags += Tag("tag1")
        queries += Query.boolean().required("b", "booleanQuery")
        receiving(Body.json("json").toLens())
    } bindContract GET to { Response(OK) }
}

We've deprecated the old

contract()

functions for the time being - they were getting a little out of hand with 8 or so overloaded (and all defaulted anyway) args, hence this change. Have a play and let us know if you like/hate it. Also in this release, there's a new

http4k-template-freemarker

module. 🙄

@krtko yep - we already build http4k against java 11 and my current project is also happily using Java 11 in prod. We're also using Google Jib, which is pretty cool for building efficiently sized docker images straight from Gradle. https://github.com/GoogleContainerTools/jib

@tom_barnsbury I think they should be just as discoverable in the IDE - maybe I'm wrong? As for the extension vs member thing, it's a stylistic thing about what felt right when I wrote it. here's the code to explain a bit:

interface Approver {
    fun <T : HttpMessage> assertApproved(httpMessage: T)
}

fun Approver.assertApproved(response: Response, expectedStatus: Status) =
    assertApproved(response.apply { assertEquals(expectedStatus, response.status) })

fun <T : HttpMessage> Approver.hasApprovedContent(): Matcher<T> = ...

The interface method is generified by HttpMessage, so for the first extension to be specific to

Response

felt a little wrong. The second was specific to hamkrest, which is totally outside the remit of the actual interface. On top of that, we don't even ship hamkrest with the module, so whilst convienient, it's even further away conceptually from the main interface.