How to modify an Akka HttpResponse? - scala

I am using Akka and I want to modify the entity of a HttpResponse. In particular, I want to modify the body or header of the particular HttpResponse. Since HttpResponse is a final class, I cannot modify it, but copying and setting a slightly modified body would be sufficient.
Here's my code:
val handler = Source.single(context.request)
.via(flow)
.runWith(Sink.head)
.flatMap { r =>
logger.info(s"Status code: ${r.status}.")
val copyR = r.copy(status = r.status, headers = r.headers, entity = ???, protocol = r.protocol)
context.complete(copyR)
}
Is there an elegant way to parse the entity and modify certain elements of the DOM?

Related

Modify contentHeaders of Swagger Codegen methods in kotlin

I'm using swagger codegen for my REST API calls. For authentication purposes i need to send a session-token within the headers of every request. This is currently done, via APIClients' defaultHeaders
open class ApiClient(val baseUrl: String) {
companion object {
...
#JvmStatic
var defaultHeaders: Map<String, String> by ApplicationDelegates.setOnce(mapOf(ContentType to JsonMediaType, Accept to JsonMediaType))
...
}
}
The way swagger generates the code, these headers can only be modified once.
ApiClient.defaultHeaders += mapOf("Authorization" to userSession!!.idToken.jwtToken)
The problem with this is, that i cannot change the token (e.g. because another user logged in within the application lifetime). Looking deeper into the generated code, before each request is sent, a merge of both defaultHeaders and requestConfig.headers (=contentHeaders) is being made.
inline protected fun <reified T: Any?> request(requestConfig: RequestConfig, body : Any? = null): ApiInfrastructureResponse<T?> {
...
val headers = defaultHeaders + requestConfig.headers
...
}
The given RequestConfig object comes from every api call. However it is not possible to change these contentHeaders. Also they are empty by default.
fun someAPIRestCall(someParam: kotlin.String) : Unit {
val localVariableBody: kotlin.Any? = type
val localVariableQuery: MultiValueMap = mapOf()
val contentHeaders: kotlin.collections.Map<kotlin.String,kotlin.String> = mapOf() // THESE WILL BE MERGED WITH defaultHeaders
val acceptsHeaders: kotlin.collections.Map<kotlin.String,kotlin.String> = mapOf("Accept" to "application/json")
val localVariableHeaders: kotlin.collections.MutableMap<kotlin.String,kotlin.String> = mutableMapOf()
localVariableHeaders.putAll(contentHeaders)
localVariableHeaders.putAll(acceptsHeaders)
val localVariableConfig = RequestConfig(
RequestMethod.POST,
"someEndpointURL"),
query = localVariableQuery,
headers = localVariableHeaders // THESE WILL BE MERGED WITH defaultHeaders
)
val response = request<Unit>(
localVariableConfig,
localVariableBody
)
...
}
Is it possible to tell swagger-codegen to include some kind of parameter to the generated method signature to add values to those contentHeaders?
EDIT:
This is the current code-gen call within my gradle build chain
task generateSwagger(type: JavaExec) {
main = "-jar"
args "swagger-codegen-cli-2.4.7.jar", "generate", "-i", "./swagger_core.yml", "-l", "kotlin", "-o", "./tmp/RestApi", "--type-mappings", "number=kotlin.Long"
}
By now, i found a solution, that is more of a hack, but it works.
As i am using gradle to build the app, i introduced a task, that changes the generated swagger code, before it actually compiles.
task editAPISources {
def token = "Map<String, String> by ApplicationDelegates.setOnce(mapOf(ContentType to JsonMediaType, Accept to JsonMediaType))"
def value = "MutableMap<String, String> = mutableMapOf(ContentType to JsonMediaType, Accept to JsonMediaType)"
def file = new File("./app/tmp/RestApi/src/main/kotlin/io/swagger/client/infrastructure/ApiClient.kt")
def newConfig = file.text.replace(token, value)
file.write newConfig
}
The result is a now changeable header :=
#JvmStatic
var defaultHeaders: MutableMap<String, String> = mutableMapOf(ContentType to JsonMediaType, Accept to JsonMediaType)

Gatling httpRequest with dynamic method from collection

I want to build a Gatling scenario from a collection of structured data (StructuredDataCollection).
My problem is, that I'm unable to pass in the "method" (as in HTTP method) from an element from the collection into the http call of the actual test.
Here's a code snippet.
def testScenario(duration: Int) = scenario("SO").during(duration) {
exec {
session => {
val test = StructuredDataCollection.next()
val title = test.title
val method = test.method // Not being used, because it does not work like that :(
val endpoint = test.endpoint
val requiredParameters = test.requiredParameters
val code = test.code
session
.set("title", title)
.set("methodFUG", method).set("endpoint", endpoint)
.set("requiredParameters", requiredParameters)
.set("code", code)
}
}
.exec(
http("${title}")
.httpRequest("get", "${endpoint}") // TODO: method can't be passed in as an expression.
.queryParamMap("${requiredParameters}")
.check(status.is("${code}"))
)
}
As you can see, I've hard-coded "get", but I'll need that to be replaced with the actual value from the method property from the current selected item from the collection.
Unfortunately, Gatling's DSL isn't available in all the places where you'd expect it to be, and it's just reading that as a string.
It took me some time to realize, that
http("${title}").httpRequest("${methodFUG}", "${endpoint}") will actually make a HTTP call with the invalid method "${methodFUG}" and not the value from the collection element, which could be "GET", "POST", "PUT", "DELETE", and so on.
httpRequest signature is (method: String, url: Expression[String]), see documentation.
It cannot take an Expression, only a static String.

Akka HTTP set response header based on result of Future

I'm designing a REST service using Akka-HTTP 2.0-M2 and have come across a situation where I'd like to supply additional headers which are dependent upon the reply of the queried Actor.
Currently, I have the following...
val route = {
path("oncologist") {
get {
parameters('active.as[Boolean].?, 'skip.as[Int].?, 'limit.as[Int].?).as(GetAllOncologists) {
req =>
complete {
(oncologistActor ? req).mapTo[OncologistList]
}
}
}
}
While this is returning without issue. I'd like to move some of the properties of OncologistList into the response header rather than returning them in the body. Namely, I'm returning total record counts and offset and I would like to generate a previous and next URL header value for use by the client. I'm at a loss on how to proceed.
I think you can use the onComplete and respondWithHeaders directives to accomplish what you want. The onComplete directive works with the result of a Future which is exactly what ask (?) will return. Here is an example using a case class like so:
case class Foo(id:Int, name:String)
And a simple route showing onComplete like so:
get{
parameters('active.as[Boolean].?, 'skip.as[Int].?, 'limit.as[Int].?).as(GetAllOncologists) { req =>
val fut = (oncologistActor ? req).mapTo[Foo]
onComplete(fut){
case util.Success(f) =>
val headers = List(
RawHeader("X-MyObject-Id", f.id.toString),
RawHeader("X-MyObject-Name", f.name)
)
respondWithHeaders(headers){
complete(StatusCodes.OK)
}
case util.Failure(ex) =>
complete(StatusCodes.InternalServerError )
}
}
}
So if we get a successful result from the ask on oncologistActor we can then leverage the respondWithHeaders to add some custom headers to the response. Hopefully this is what you were looking for.

Idiomatic way to create a basic HTTP Post request with Akka HTTP

I'm trying to figure out how to create a basic HTTP POST request with the Akka HTTP library. This is what I came up with:
val formData = Await.result(Marshal(FormData(combinedParams)).to[RequestEntity], Duration.Inf)
val r = HttpRequest(POST, url, headers, formData)
The thing is that it seems a bit non-idiomatic to me. Are there other ways to create a HttpEntity from FormData? Especially the fact that I have to use Await or return a Future even though the data is readily available seems overly complex for such a simple task.
You can use Marshal in a for comprehension with other Futures, such as the ones you need to send the request and unmarshall the response:
val content = for {
request <- Marshal(formData).to[RequestEntity]
response <- Http().singleRequest(HttpRequest(method = HttpMethods.POST, uri = s"http://example.com/test", entity = request))
entity <- Unmarshal(response.entity).to[String]
} yield entity
Apparently a toEntity method was added to the FormData class at some point. So this now seems like the simplest solution to the problem:
val formData = FormData(combinedParams).toEntity
val r = HttpRequest(POST, url, headers, formData)
You can also use RequestBuilding:
Http().singleRequest(RequestBuilding.Post(url, formData)).flatMap(Unmarshal(_).to[String])

PlayFramework Testing: Uploading File in Fake Request Errors

I want to test my method, which requires uploading a file. It is initialized like this:
val tempFile = TemporaryFile(new java.io.File("/home/ophelia/Desktop/students"))
val part = FilePart[TemporaryFile](
key = "students",
filename = "students",
contentType = Some("text/plain"),
ref = tempFile)
val files = Seq[FilePart[TemporaryFile]](part)
val formData = MultipartFormData(
dataParts = Map(),
files = Seq(part),
badParts = Seq(),
missingFileParts = Seq())
I pass it into the FakeRequest:
val result = route(
FakeRequest(POST, "/api/courses/"+"4f3c4ec9-46bf-4a05-a0b2-886c2040f2f6"+"/import" )
.withHeaders("Authorization" -> ("Session " + testSessionA.id.string))
.withMultipartFormDataBody(formData)
)
But when I run the test I get the following error:
Cannot write an instance of play.api.mvc.AnyContentAsMultipartFormData to HTTP response. Try to define a Writeable[play.api.mvc.AnyContentAsMultipartFormData]
What am I doing wrong and how to fix it? I looked on the internet, I didnt find any useful way to understand and resolve this problem.
It's important to remember that http requests are entirely text. route() takes an implicit Writeable to convert the body type of the provided request into text. Without the right Writeable, there is no way to know how to turn MultipartFormData into a request body.
There doesn't seem to be a Writeable for MultipartFormData, but you can provide your own. jroper has a great Writeable you could use for reference. (EDIT: That code is buggy, here's a working Writeable for AnyContentAsMultipartFormData)
Once you have your Writeable, you will need to make it accessible to your call to route(). Bear in mind, you currently have a FakeRequest[AnyContentAsMultipartFormData], not a FakeRequest[MultipartFormData]. You can either convert your request first:
val request = FakeRequest(POST,
"/api/courses/"+"4f3c4ec9-46bf-4a05-a0b2-886c2040f2f6"+"/import" )
.withHeaders("Authorization" -> ("Session "))
.withMultipartFormDataBody(formData)
route(request.map(_.mdf).asInstanceOf[FakeRequest[MultipartFormData[TemporaryFile]]])
or make your Writeable a Writeable[AnyContentAsMultipartFormData].
route for a given Request[T] requires an implicit parameter of type Writeable[T] that knows how to serialize the request body, because it will actually call the controller action just like an actual web request would, by pushing bytes onto it.
The problem is that there is no Writeable[MultipartFormData] predefined (you can see which are in play.api.test.Writeables).
This means you basically have two options:
write your own Writeable that serializes a MultipartFormData into bytes
Skip the routing part and call the action directly instead, like in the accepted answer in Play Framework Testing using MultipartFormData in a FakeRequest. This way of testing actions takes a shortcut and does not actually serialize and deserialize the request.
IMHO the first option is way too much pain for the gain, but if you go down that road, maybe contribute it to play when you succeed.
One of the possible solutions is to use wsUrl. For example
"File uploading action" should {
"upload sent file and result in ID" in {
val file = Paths.get(getClass.getResource("/1.txt").toURI)
val action = wsUrl("/upload").post(Source.single(FilePart("file", "hello.txt", Option("text/plain"), FileIO.fromPath(file))))
val res = Await.result(action, timeout)
res.status mustBe OK
res.body contains "123"
}
}