We are using Service Fabric for hosting our messaging service ASP.NET Core web API (leveraging signalr) and React web application as a client. Everything works exactly as expected on local machines but not on Azure. We have configured CORS policies for cross-origin handling since the service and the web app are hosted on different servers. Configured sticky sessions in load balancer. This CORS Policy works in local machine with the service and client hosted on different ports.
Post hosting the application on Azure, I get an Error in the browser console as
Error during WebSocket handshake: Unexpected response code: 500
The issue is very likely to be happening because of CORS.
Looking the screenshot you provided, it is possible to see the CORS exception and, as you are aware, the front-end application calling the SignalR service are hosted on different locations(The domain is the same but different ports).
The CORS settings you applied probably didn't work.
You have two solutions:
Configure CORS in the ASP.NET CORE, so SignalR can accept the call from other domains.
Host both on same domain + port to avoid CORS
Related
I am trying to configure Azure Application Gateway with ADFS. The Backend pool points to ADFS Web Application Proxy. The backend health check is reporting as unhealthy.
I am getting an a error: received invalid status code 404 in the backend servers http response
Everything appears to be configured correctly and I can access the site when bypassing the App Gateway
This was resolved by re-configuring the health probe
In my case with the App Service as a backend pool, I had to create a custom Health probe(http-probe for ex.) to be used in the HTTP setting(http for ex.), where the HTTP setting(http for ex.) is the one configured in the Request Routing Rule.
CORS says that:
A web application executes a cross-origin HTTP request when it requests a resource that has a different origin (domain, protocol, and port) than its own origin.
That been said, look at this scenario. I have two apps deployed on the azure.
https://myApp.azurewebsites.net .NET FW app that has a Angular client.
https://myMicroservice.azurewebsites.net .NET CORE API.
Since both apps are in the same site (origin) azurewebsites does that mean that I don't need to configure CORS?
Note: I already have configured CORS on the .NET CORE app to allow the https://myApp.azurewebsites.net origin.
Here, the same origin means that xxx.azurewebsites.net should be the same one(as well as xxx).
So in your case, you need to enable CORS. Otherwise, the access is not allowed.
I have an Azure app service and in some cases I need to send a web request to a non-azure webserver. What do I need to do to make it possible.
Currently the web request fails with no clear error message.
In response to a HttpClient Put request I get a System.Net.WebException exception which says there were errors.
THe same request works from a desktop application.
If your webserver is reachable from the internet you should be able to access it through your App Service. Try to log a ping to your webserver and google (8.8.8.8).
If your App Service is in a VNET you should enable some outbound rules to your webservers IP adress.
The server I am connecting to is an other Azure service. After some more investigating, It appears that I can connect to it if I do not use SSL (i.e. http://) but the connection is immediately closed when using SSL (https://). I assume that the problem must be related to the use of SSL.
I followed the docs here https://learn.microsoft.com/en-us/azure/application-gateway/application-gateway-create-multisite-portal but still getting the error :
Azure Application Gateway error 502 - Web server received an invalid response while acting as a gateway or proxy server. There is a problem with the page you are looking for, and it cannot be displayed. When the Web server (while acting as a gateway or proxy) contacted the upstream content server, i
Any help?
About the 502 errors after configuring the application gateway, The main reasons are as follows.
NSG, UDR or Custom DNS is blocking access to backend pool members.
Back-end VMs or instances of virtual machine scale set are not responding to the default health probe.
Invalid or improper configuration of custom health probes.
Azure Application Gateway's back-end pool is not configured or empty.
None of the VMs or instances in virtual machine scale set are healthy.
Request time-out or connectivity issues with user requests.
References: Troubleshooting bad gateway errors in Application Gateway
Just a reminder, after you changing health probe, please check if you select the use custom probe.
Issue: Receiving 502 when you have Web App as the backend pool.
This is how the default probe from Application gateway looks like http/htpps://127.0.0.1:port/
But Web App doesn't respond to localhost, so Application gateway will be receiving 404 for the request sent and it will mark that Web Application unhealthy.
In your scenario, you need to create 3 backend pool where you add one web App in each pool. Then create HTTP setting and enable "Use App Service" check box.
How to enable Use App Service
Then create 3 separate rules to achieve your scenario.
Listener1(test.mydomain.com) ---> HTTP Settings (enable Use App Service) --> Backend Pool(test.mydomain.com)
Listener2(staging.mydomain.com) ---> HTTP Settings (enable Use App Service) --> Backend Pool (staging.mydomain.com )
Listener3(prod.mydomain.com) ---> HTTP Settings (enable Use App Service) --> Backend Pool (prod.mydomain.com)
I have two VMs with IIS that host my application with Azure Application Gateway distributing the traffic. The gateway is configured to offload SSL and everything is working fine.
However, I'd like to use client certificate authentication on one of the paths of the application - on NetScaler (or some other load balancer) I'd simply put serialized client certificate into HTTP Header (X-Client-Cert).
Can I do something similar with Application Gateway?
At the moment thats not possible, but is in the pipeline of product development of the azure product team.