asp.net mvc - How to make HttpClient relay traffic show up in Fidder or Charles? -

i have simple web api project based on example: http://aspnet.codeplex.com/sourcecontrol/latest#samples/webapi/relaysample/program.cs

however, in above sample relay working local server, in project relay working external web server real address; companyx.com

i using relay service (or, web proxy service) through browser, example, in browser request relayservice.com/companyx. relay service responds data external companyx.com site.

the relay works great, headers not correct , need see httpclient sending remote companyx.com server.

in fiddler or charles, request/response browser relayservice.com listed, request/response httpclient relayservice.com never shows up.

the relayservice.com running locally on machine, in iis7, i'm using hosts file direct traffic relayservice.com.

i have tried several variation of following when creating httpclient:

        var clienthandler = new httpclienthandler         {             cookiecontainer = cookies,             usecookies = true,             usedefaultcredentials = false,             proxy = new webproxy("http://localhost:8888"),             useproxy = true,             automaticdecompression = decompressionmethods.gzip,              allowautoredirect = false,              clientcertificateoptions = clientcertificateoption.automatic         };           httpclient client = new httpclient(clienthandler); 

update

if change useproxy = false service continues work, when fiddler open or closed.

with useproxy = true service fail, if fiddler open, following error:

object reference not set instance of object.  @ system.domainnamehelper.idnequivalent(string hostname) @ system.net.httpwebrequest.getsafehostandport(uri sourceuri, boolean adddefaultport, boolean forcepunycode) @ system.net.httpwebrequest.generateproxyrequestline(int32 headerssize) @ system.net.httpwebrequest.serializeheaders() @ system.net.httpwebrequest.endsubmitrequest() @ system.net.connection.completeconnection(boolean async, httpwebrequest request) 

with useproxy = true , fiddler closed, following (obvious) error:

no connection made because target machine actively refused 127.0.0.1:8888 

in same solution using httpwebrequest download data web , show in fiddler, seems issue httpclient.getasync()

i have tried on 2 machines identical results.

i have been struggling day, appreciated.

just recap: * relayservice.com running locally on machine, in iis7

• hosts file has "127.0.0.1 relayservice.com"

• relayservice.com mvc web api site uses httpclient.getasync() download content live web

• fiddler/charles running locally on same machine

• browser traffic local relayservice.com appears in fiddler/charles

• httpclient.getasync() live web traffic not appear in fiddler/charles

• fiddler/charles both date versions.

thanks again

you don't need in hosts file if you're using fiddler; can use fiddler's tools > hosts redirect traffic anywhere you'd like.

when trying capture traffic service account (e.g. asp.net acccount) typically want configure account use proxy; see http://fiddler2.com/blog/blog/2013/01/08/capturing-traffic-from-.net-services-with-fiddler details on that. if that, shouldn't need configure proxy object directly in code.

the exception you've shown suggests here's bug in generateproxyrequestline function. there change if update this: new webproxy("http://localhost:8888"); new webproxy("127.0.0.1", 8888); ?

generally speaking, .net applications bypass proxy urls pointed @ //localhost or //127.0.0.1, when debugging fiddler it's common use service url of //localhost.fiddler traffic sent proxy.