Hi fellow Gatling users!
I need to upload a file to AWS S3 using Gatling 3.1.1. In Gatling 2.3.x below code worked like a charm:
`
http(“S3 file upload”)
.post(url)
.formParamMap(fields(_).get.asScala.toMap.success)
.formUpload(“file”, “file.wav”)
`
It worked fine, because the attached file was sent as last part in the multipart body (before dynamic form params).
In Gatling 3.1.1 however, the behaviour changed and now the attached file is sent first, before dynamic form param fields. It breaks S3 authorisation mechanism - S3 expects key and signature fields before actual file contents.
The reason is in the below Gatling source code (io/gatling/http/request/builder/HttpRequestExpressionBuilder.scala):
`
private def configureBodyParts(session: Session, requestBuilder: AhcRequestBuilder, bodyParts: List[BodyPart]): Validation[AhcRequestBuilder] =
for {
params ← httpAttributes.formParams.mergeWithFormIntoParamJList(httpAttributes.form, session)
stringParts = params.asScala.map(param => new StringPart(param.getName, param.getValue, charset, null, null, null, null, null))
parts ← Validation.sequence(bodyParts.map(_.toMultiPart(session)))
} yield requestBuilder.setBodyBuilder(new MultipartFormDataRequestBodyBuilder((parts ++ stringParts).asJava))
// ^^^^^ - file contents go first
`
If I send the form params manually, it works fine:
`
.bodyPart(StringBodyPart(“key”, fields().toOption.get(“key”)))
.bodyPart(StringBodyPart(“policy”, fields().toOption.get(“policy”)))
// etc.
`
But the form params are dynamic (retrieved from earlier request and saved in a session) and I cannot put the static list of these params in the source code (different S3 regions require different auth fields).
There is no method I’m aware of to set body parts from a Map or Seq. I can only get them from the user session variable using formParamMap(map: Expression[Map[String, Any]]) method.
I’ve tried to use signature calculator and request body processor to maybe reorder the parts before sending the request, but without success.
Is there any other way I could ensure the dynamic form fields go always before file part in the multipart body?
Thanks in advance,
Adam
