Can I ask a philosophical question @dave ? Why do Java/Kotlin http servers like http4k, ktor, vertx also include a client module? There's already mature, full featured, easy to use http clients -- okhttp or fuel or retrofit (a little different, but same idea) for example. Meanwhile Flask doesn't include a client, neither does Laravel or Express. Is it something about the JVM? Is it just because it's easy to rearrange HttpHandlers? Somehow the other day I thought of how different building an http4k server is from a Flask one and was curious why. Thanks.

Going to start a new project with http4k soon and there was a hint in twitter a month or so ago that some sort of generator or template-y thing is in the works. Is that something that might be revealed soon or should i not hold m breath 😀?

@dave is there a recommended production server? I remember seeing something, some time ago, about Undertow being recommended. Is that true? Any special reasons for it?

Hi everyone. JTLYK that (as promised) the first 2 parts of the http4k 2020 masterplan are now in place. We'll be announcing this stuff more formally in due course, but thought we'd give you all a sneak peek... 🙃 Firstly, we've done a complete rebrand of the website. Please check it out and DM us with any feedback (good or bad!). https://www.http4k.org Next, the http4k Toolbox CLI is also now available for installation through SDKman! and Brew, allowing you to: 1. Generate a custom ZIP with entire project contents, including build tooling and packaging 2. Generate http4k Servers, Clients and Models from an OpenAPI V2/3 specification 3. Generate Model Data Classes from JSON/YAML/XML documents. Installation instructions can be found here: https://www.http4k.org/installation/ More good stuff coming soon, including a website version of the Toolbox and the next major release (v4), where we'll be doing a bit of a spring clean on the codebase. We're also looking at ways of packaging educational content on the site, maybe screencasts or training etc. One final thing, we'd like to collect examples of success stories using http4k in the wild. If you're on a project or at a company who is using the library and would like to be featured, please let us know!

I’m working on an old-fashioned server-side rendered app in http4k and need some sort of cookie based sessions. Did anybody come up with this yet before I roll my own?

Is there a way to publish percentiles from

MetricFilters.Server.RequestTimer

? I seem to get only the

count

,

mean

,

sum

and

upper

fields from

http.server.request.latency

metric published using the

RequestTimer

metric filter.

Hei, I get the following error when trying to define a endpoint that starts with a dynamic path. (Example:

Path.of("system", "The target system ") / "/feed"

.

Exception in thread "main" java.lang.IllegalArgumentException: Fixed path segments cannot contain /. Use the "a / b" form.

Any ideas?

Are you referring to git tags? We don't use them to denote releases

Hi all Does it exist a sample, how to use OAuth with Keycloak?

Does http4k handle requests async?

Is it possible to exclude some of the endpoints from the OpenApi Specs? There are some internal endpoints, that I want to hide from the specs endpoint.

Which reminds me, we've just added a repo of self contained example projects which showcase the various features of http4k. If there's anything you'd like to see then please let us know! https://github.com/http4k/examples

Hi everyone! Reminder that we'll be hosting http4k office hours later today. As well as the usual stuff, we can talk about the various http4k posts across the internet in the last week, or about our plans for the new http4k-connect project which we started up this week. 🙃 Join us @ 4pm BST, 8am PDT, 5pm CEST via Zoom: https://t.co/kb7EcuVbvi Sli.do link for any questions and proposed topics: https://app.sli.do/event/kqabztdc/live/questions

Also - (if this is a wishlist! ) - AWS XRay connector/collector for http4k or example.

Oh yes, some light-weight connectors for Google Cloud services would be great. Same reason as above, don't want to pull in a million Google libraries just to put a message on a queue or get a value out of Datastore.

Is there a way to configure max requests simultaneously for Undertow?

apologies for anyone who got locked out of the http4k office hours thing - technical problems..

I am wondering How can I pass Environment setting to a http4k application using gadlew?

Hi @dave after upgrading from http4k 3.251 to 3.252 (or beyond) i get 403 errors when my app receives the callback from an oauth provider. This happens using the Apache server. If I switch to Jetty or Netty, the 403 problem goes away. Is there something special I should configure when using the Apache server?

Erm no there isn't one actually. we use a custom version of CatchAll.

I am tring to implement an OAuth server by using http4k OAuthServer class. Every interface and method are quite clear, except the create access token one:

fun create(
        clientId: ClientId,
        tokenRequest: AuthorizationCodeAccessTokenRequest,
        authorizationCode: AuthorizationCode
    ): Result<AccessToken, AuthorizationCodeAlreadyUsed>

I need a way to associate the access token with the authenticated user here. I was thinking that I could use the requests contexts api to pass the logged user somehow, but this method doesn’t have access the request object. I don’t know if I am not seeing something obvious here, but I can’t find a way to implement this.

You can use a composite. Example here: https://www.http4k.org/cookbook/typesafe_http_requests_with_lenses/

Hi, getting started with http4k and have some troubles understanding some concepts. I try poking around but got stuck here. I want to get the code from a from posted:

val codeField = FormField.required("code")
        val pageForm = Body
                .webForm(Validator.Strict, codeField)
                .toLens()

        val validForm = pageForm(request)
        val code = codeField(validForm)

but when I call the api from a static JS fetch request I get a 500 error:

org.http4k.lens.LensFailure: header 'content-type' is not acceptable

for the last line of code. Why does it check the content-type header if it's a Body lens ? And how to get around with it ? the JS fetch request is:

fetch{"/check", {
  method: "post",
  body: "code=XXXX"
})

tried with FormData and multipart got the same error.

Guys,  I had started a library last year to have a wrapper over Jackson for a type safe programming. Please have. a look at it, remarks are highly appreciated and. if you believe it can. be taken further please help to contribute https://github.com/sahlone/kson

is there a way to get info like userAgent or ip? Or do you have to get that from a custom server implemetation?

Hi, I've setup a small netty server in a project to serve prometheus scrapes. It works fine, but a little while after I hit the endpoint I start seeing

2020-10-08T19:17:15.008682Z [WARN] An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception. exception_message=Connection reset by peer exception_name=java.io.IOException

Is there something I can setup to avoid this stacktrace? I assume this is because of keepalive.

Hi, for a demo I wrote a test fonction about Lenses like this:

@Test
    fun `Lens exemple`() {

        data class User(val name: String, val age: Int)

        val idLens = <http://Path.int|Path.int>().of("id")
        val jsonBody = Body.auto<User>().toLens()

        val user: HttpHandler = routes(
            "users/{id}" bind GET to { r: Request ->
                jsonBody.inject(User("Tom", 30 + idLens.extract(r)), Response(OK))
            }
        )

        val responseOk = user(Request(GET, "users/2"))
        val resposeObject = jsonBody.extract(responseOk)
        resposeObject.age shouldBe 32
    }

But I get a Parser error:

Signature Parse error: expected '<' or ';' but got  
	Remaining input:  exemple$User;>;

If I move the

User

class out of the function is all good, but I was wandering it it’s supposed to not work or it’s a bug and should I report it (and if so, to whom is it your fault or Jackson’s).

Hi, I deployed a http4k app using Apache Server on Cloud Foundry but couldn't figure out why I can't access it... local curl (on localhost) worked ok but any way to access from outside always got a 400 (with message: "Not authoritative"). So I tried locally starting a server with simply

app.asServer(ApacheServer(8080))

accessing from

<http://localhost:8080>

no problem, but trying using the loopback ip

127.0.0.1

or

0.0.0.0

didn't work.

➜ curl --verbose <http://127.0.0.1:8080> 
*   Trying 127.0.0.1:8080...
* TCP_NODELAY set
* Connected to 127.0.0.1 (127.0.0.1) port 8080 (#0)
> GET / HTTP/1.1
> Host: 127.0.0.1:8080
> User-Agent: curl/7.68.0
> Accept: */*
> 
* Mark bundle as not supporting multiuse
< HTTP/1.1 400 Bad Request
< Connection: close
< Date: Mon, 12 Oct 2020 13:36:26 GMT
< Server: Apache-HttpCore/5.0.2 (Java/11.0.8)
< Content-Length: 17
< Content-Type: text/plain; charset=ISO-8859-1
< 
* Closing connection 0
Not authoritative%

I tried specify the address to the server

app.asServer(ApacheServer(8080, InetAddress.getByName("0.0.0.0")))

but no luck either. Finally gave up and move to Jetty which worked as a charm, but still wanting to know if you have an explanation or a configuration that should work with Apache. Thanks.

@Razvan All of the code samples on the site come directly from the http4k source tree (and are hence compiled into the build to ensure they're at least syntactically correct). because each "page" is in the same package, there can be code referenced in later snippets that appeared in others