Websocket support

[leandro]

Hi there!

I am interested in using the websocket connection that Mango provides. I am also interested in developing apps with other frameworks other than AngularJS that may be served separately from Mango.

I know of the REST API, but hooking into the websocket provides the responsiveness that I am looking for.

I am wondering if it is possible for you guys to add the ability to enable cross-origin support for the websocket?

Regards,
Leandro

[Jared Wiltshire]

@leandro said in Websocket support:

I am wondering if it is possible for you guys to add the ability to enable cross-origin support for the websocket?

Yes definitely, I wasn't aware that it wasn't working. I'll make an issue around this and look into it.

[phildunlap]

Hi Leandro,

Sorry to be delayed in getting back to you. Have you attempted changing the env.properties associated with CORS? I believe the relevant section of the code for that part of the configuration happens here: https://github.com/infiniteautomation/ma-core-public/blob/main/Core/src/com/serotonin/m2m2/web/mvc/spring/MangoWebSocketConfiguration.java#L77

The console on the left is with the env.properties

rest.cors.enabled=false
rest.cors.allowedOrigins=

while the console on the right has the properties

rest.cors.enabled=true
rest.cors.allowedOrigins=localhost:8080,127.0.0.1:8080

Note that in the right console I am still getting a 403 error for my request to 127.0.0.1:8080, probably because I didn't login on that hostname and don't have a valid session in an accessible cookie to send as a header in the websocket request. The reason I am getting 405s is that I didn't try to register for a real websocket, I was merely testing if the origin would be permitted, and it was. I can provide a more complete example if requested where the logging in gets done and a session cookie is available to the browser's JavaScript.

Hope that's helpful!

[leandro]

Hi,

Thanks for the input and sorry for the long delay. I am finally able to tackle this again.

I have tried as you suggested and I too get the 403 and 405 errors. Can you provide an example of how to do this while logged?

I think that I should be able to run :

new WebSocket('ws://localhost:8080/rest/v1/websocket/point-values')

or (not sure of the difference):

new WebSocket('ws://localhost:8080/rest/v2/point-values')

within the console of a correctly logged in session and connect to the ws server.

[leandro]

Actually, never mind. I am able to connect to the websocket on a console on a logged in tab.

Now I need to figure out how to log in and use that in my connection.

[phildunlap]

You can watch the network tab for an example of acquiring a session cookie and xsrf token by using the /ui/login page and the network tools, or find the best example on the forum for the framework you're using.

Basic authentication and Token authentication are also options!

[Jared Wiltshire]

It looks like @leandro is opening the websocket connection from a browser, in which case only session authentication is an option. You can't set the Authorization header using the browser WebSocket API.