Capture Outgoing http/https Request from web Application hosted on Azure App Service

on azure app service, Fiddler, Proxy

If you are troubleshooting any 500 Errors caused due to any form of connectivity issues with outgoing webservice/webApi calls, you often have to capture system.net trace which is very huge and time consuming to review. I am working a way to host fiddlercore as a webjob to proxy the requests, but meanwhile I have found another technique to capture these requests.

 Step1:
Create an Azure VM with an inbound rule (NSG) allowing 8888 traffic
fiddlerproxy1.png

Step2:

Install and Run Fiddler. Fiddler options-HTTPS-Enable “decrypt https traffic” if you are capturing SSL traffic as well Fiddler options-Connections- Enable “Allow remote computers to connect”

fiddlerproxy2.png

Step3: Restart Fiddler

Step4: On the application side you only need to do this change, add the system.net proxy settings

  <system.net>
 <defaultProxy>
  <proxy autoDetect="false" bypassonlocal="false" proxyaddress="http://IpAddressOfYourAzureVM:8888" usesystemdefault="false" />
 </defaultProxy>
</system.net>

Now, all the outgoing calls from your Azure AppService should be proxied through Fiddler running on another Azure VM.