Calling a web service - reponse body transform

Support Installation and Deployment
1

Hi,

I’m very new to Tyk, so this is why I post this question under setting up Tyk. This is a very newbie question.

My basic case is the following: call a webservice, transform the request body from json, receive the response and tranform the response body from xml to json.

This is what I have done:

  • I’m running Tyk on premise in docker containers
  • I have chosen a simple test web service: http://www.webservicex.net/geoipservice.asmx
  • Created an API with the dashboard
  • In the core settings: added a name, slug, listen path and set the Authentication mode to “Open”
  • In the endpoint designer: added an endpoint
  • The endpoint: set method to POST, no extra path
  • The endpoint: added Body transform, for the request → result is a XML
  • The endpoint: added Modify request headers, added the required headers for content-type and SOAPAction
  • Tested the API with Postman: worked great!
  • The endpoint: added Modify response headers, removed the unwanted headers and added the content-type application/json
  • The endpoint: added the Body transform for the response body. I started simply by returning a fixed json { “result” : “OK” }
  • Updated and then tested the API with Postman: Postman reports that the API does not reply
  • Checked the docker output:level=error msg=“Error unmarshalling XML: xml.Decoder.Token() - XML syntax error on line 1: invalid character entity & (no semicolon)”
  • The endpoint: removed the response Body transform → API works
  • Checked the validity of the XML returned by the service: XML seems to be valid.

What could I do to fix this / what did I do wrong?

Thanks in advance for your answer.

Ger

2

Can you give this XML input so we can validate it against our XML parser?

3

Hi,

Thanks for the quick reply.

The response xml:

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <soap:Body>
        <GetGeoIPResponse xmlns="http://www.webservicex.net/">
            <GetGeoIPResult>
                <ReturnCode>1</ReturnCode>
                <IP>192.168.1.1</IP>
                <ReturnCodeDetails>Success</ReturnCodeDetails>
                <CountryName>Reserved</CountryName>
                <CountryCode>ZZZ</CountryCode>
            </GetGeoIPResult>
        </GetGeoIPResponse>
    </soap:Body>
</soap:Envelope>

Ger

4

Can you also pls put here transformation you trying to apply?

Thank you!

5

{
“result” : “OK”
}

I set the input type to XML.

7

Hi

I had a look into this and the problem we have is that the Go XML parser we use can’t handle the response body it has to parse from that endpoint. I tested against httpbin’s XML endpoint and it worked fine so unfortunately is an edge case to do with what the geoipservice is returning.

8

Hi,

Thanks for your reply. This was only a test for me, so I’m not beholden to this endpoint. I will try to use the real endpoint soon. (I am curious to why this failed: was it the namespaces?)

Thanks for all the help.

Ger

9

As much as I could gather from diving into the code was there is an entity returned in the response that isn’t in the Go XML packages entity library.

Josh