Singlar Core Apache port forwarding issue

[JinsPeter]

I'm working on a .net core web api app where I use signalr core. I used apache to redirect the web request to www.myserver.com to http://127.0.0.1:5000 which is where my kestral runs.

<VirtualHost *:80>
  ServerName www.myserver.com
  ProxyPreserveHost On
  ProxyPass / http://127.0.0.1:5000/
  ProxyPassReverse / http://127.0.0.1:5000/
  ErrorLog <errorLogLocation>/<errorLogFilename>.log
  CustomLog <errorLogLocation>/<customErrorLogFilename>.log common
</VirtualHost>

The issue is the http request works fine, signalr handshake works fine, gets me the connection id, but the websocket connection fails with a message, error establishing connection with
ws://www.myserver.com/SignalR?id='some-guid-here'.

I'm using RHEL and Apache.
Is there a way to give domain name to Kestral in linux without apache.?

[ralsu091]

You can host asp.net core with nginx on linux:https://docs.microsoft.com/en-us/aspnet/core/publishing/linuxproduction?tabs=aspnetcore2x

[BrennanConroy]

You need to add some websockets proxy settings or use a different transport from your client

[JinsPeter]

Writing a rewrite condition on my website.conf file solved this issue for me using apache.

<VirtualHost *:80>
  ServerName www.myserver.com
  ProxyPreserveHost On
  ProxyPass / http://127.0.0.1:5000/
  ProxyPassReverse / http://127.0.0.1:5000/
 
//Added this Rewrite part to manage ws connection
   RewriteEngine on 
  RewriteCond %{HTTP:UPGRADE} ^WebSocket$ [NC] 
  RewriteCond %{HTTP:CONNECTION} Upgrade$ [NC] 
  RewriteRule /(.*) ws://127.0.0.1:5000/$1 [P]

  ErrorLog <errorLogLocation>/<errorLogFilename>.log
  CustomLog <errorLogLocation>/<customErrorLogFilename>.log common
</VirtualHost>

So Closing the issue.

[BrennanConroy]

Glad you got it working!
I'm not too familiar with Apache config, but I think I saw someone have multiple ProxyPass settings, one for http and one for ws

[JinsPeter]

Yeah In that case, you will need different pathbase for each.
like we have http;//example.com/api for http connection and ws://example.com/hubname for signalR connection.
But in our case of signalR core, the handshake request to singnalR that establishes the connection and bring the connection id is an http request. which will be https://example.com/hubname.
So we need to forward http request to example.com/hubname as http and ws request to example.com/hubname as ws.

[JinsPeter]

I have the exact same issue now with nginx. Any solution??

[BrennanConroy]

https://www.nginx.com/blog/websocket-nginx/

[JinsPeter]

this issue here give the answer