Zuul - Websocket proxy

[aivans]

We currently have a direct Websocket connection that goes to a backend webservice (via a load balancer F5).

If we get F5 out of the picture in what regards webservices, and F5 will only talk to Zuul (let's say), can we proxy a websocket connection from browser to webservice via Zuul?

[dsyer]

Zuul 1.x is pretty much limited to HTTP as far as I know (@spencergibb correct me if I'm wrong), and the current Spring Cloud proxy filter is probably not well suited to non-REST payloads (e.g. streaming). If we move to Zuul 2.0 at some point it opens up other possibilities.

[aivans]

Hi Dave,

Is there a 2.0 for Netflix Zuul?

[dsyer]

I believe it hasn't been released yet.

[aivans]

Ok, Thanks

[paskos]

we're starting websocket development. Very very very interested in websocket support in zuul. Any news or ETA ?

[spencergibb]

See this comment from zuul issues: Netflix/zuul#112 (comment). The short is zuul can terminate websockets in v2, but full duplex channels will come after a stable v2 and they integrate http://reactivesocket.io.

[aivans]

Thanks. By scenario 1 they mean to support terminating websockets natively, ie do not plugin another 3rd party support like Spring Websockets?

[tur-ing]

Is there already an update of Zuul that supports the full duplex channels on websockets?

[dsyer]

AFAIK there is no Zuul 2.x yet (they got to a release candidate and then stalled). Just keep tracking the Netflix issue.

[cforce]

See also this alterntive: https://jmnarloch.wordpress.com/2015/11/11/spring-cloud-sock-js-stomp-zuul-no-websockets/

[kongslund]

Zuul 2 is just right around the corner but although websocket support is planned it will not be part of the first release.

Zuul 2 : The Netflix Journey to Asynchronous, Non-Blocking Systems

We are in the process of releasing Zuul 2 as open source. Once it is released, we’d love to hear from you about your experiences with it and hope you will share your contributions! We plan on adding new features such as http/2 and websocket support to Zuul 2 so that the community can also benefit from these innovations.

[mthizo247]

We have created a web socket support feature to resolve this issue. I will be creating a pull request in spring cloud netflix soon. The library and demo are currently hosted in github.

[spencergibb]

@mthizo247 I assume these https://github.com/mthizo247/spring-cloud-netflix-zuul-websocket https://github.com/mthizo247/zuul-websocket-support-demo

[spencergibb]

It's not really zuul websocket support, it's a standalone websocket proxy that happens to sit next to zuul, correct @mthizo247?

[mthizo247]

@spencergibb yes that's correct.

[ExtremeYu]

@spencergibb https://github.com/mthizo247/spring-cloud-netflix-zuul-websocket https://github.com/mthizo247/zuul-websocket-support-demo not work with zookeeper

[ExtremeYu]

@spencergibb the demo of zuul&websocket is not work with service-id,the demo just support url based service dicsovery

[spencergibb]

@ExtremeYu you'll have to speak to the author of the demo.

[barrett-rob]

Have been looking at this issue, we have a similar requirement, to proxy websocket connections through a zuul server. The requirement is slightly different though because the websocket connections will be 'special' and won't need to be handled in the same way as other requests that come through zuul.

Previously this was really easy to achieve with nodejs and http-proxy. This is an example of how to get started in java and Spring Boot: https://github.com/barrett-rob/java-websocket-reverse-proxy

NB: no safety, connection reestablishment, etc

[jonfreedman]

What's the status of Zuul 2.0? Is 2.0.0-rc.2 suitable for production use or is "the process of releasing Zuul 2 as open source" still ongoing?

[spencergibb]

You'll have to ask Netflix

[tsmgodoi]

@jonfreedman I think spring cloud now has a new gateway solution (namely, http://cloud.spring.io/spring-cloud-gateway/) which already supports Websockets.

[ExtremeYu]

@tsmgodoi what different between the zuul and spring cloud gateway????????????????????????????????

[tsmgodoi]

@ExtremeYu I don't know. I haven't used it yet. I think it is based on spring boot 2.0 and spring framework 5. So probably you won't be able to use it with existing software without updating it.

[jonfreedman]

I spent several hours yesterday looking at the alternatives, none of which I could make work with netty-socketio.

For reference these include:

• zuul 1.0 (does not support async)
• zuul 2.0 (no integration with Spring Boot)
• spring-cloud-gateway 2.0.0.M1 (requires upgrade on entire Spring stack)
• https://github.com/mkopylec/charon-spring-boot-starter (always returns HTTP 202 so socket-io does not work)
• https://github.com/mitre/HTTP-Proxy-Servlet (does not support async)
• https://github.com/barrett-rob/java-websocket-reverse-proxy (works with sockjs/stomp not socket-io)

Given what I'm trying to achieve I'm just putting this on hold until December. Currently the Spring release milestones are:

• Spring 5.0 GA - 2017-09-21
• Spring Boot 2.0.0 - 2017-11-20
• Spring Cloud Finchley.RELEASE - 2017-12-18

[berndgoetz]

@jonfreedman any new insights since December?

[spencergibb]

Zuul 2 will not be incorporated into Spring Cloud. See spring cloud gateway for websockets support