add WebSocket support

[krombel]

This is my working version for websocket support in synapse.

• The Specification for the protocol can be found here
• a working riot-web client can be build by using my matrix-js-sdk fork (or my hosted version)
• to activate the websocket component (and to decide if compression should be used or not) you need to enable "websocket" as ressource
• discussion can take place in #matrix-websockets:matrix.org

Example config to enable Websocket which shall be reverse-proxied can look like:

 - port: 8008
    tls: false
    bind_address: '127.0.0.1'
    type: http
    x_forwarded: true
    resources:
      - names: [client]
        compress: false
      - names: [websocket]
        compress: true

Signed-off-by: Matthias Kesler krombel@krombel.de

[matrixbot]

Can one of the admins verify this patch?

[matrixbot]

Can one of the admins verify this patch?

[matrixbot]

Can one of the admins verify this patch?

[MTRNord]

Hi any updates planned in the future? /me hopes this would be a better alternative for Android without GCM than doing requests every few minutes.

[krombel]

@MTRNord further development is currently stalled. I am using it daily on my server and are rebasing this from time to time.
There are currently tests missing for this part (as I currently don't know how to do them) but else I think, this is following MSC1148

[ara4n]

See also matrix-org/matrix-js-sdk#461 for the js-sdk side of this.

I realised that we've only fed back in #riot-dev and #matrix-dev on this, but for the record: the work here looks really good. I'm still unclear on how much of a benefit WS is actually providing (in terms of bandwidth usage or latency) as per matrix-org/matrix-js-sdk#461 (comment), and we haven't had bandwidth to evaluate it ourselves, otherwise we might be in a position to prioritise it higher.

However, we otherwise simply don't have bandwidth in the core team to shepherd it through currently - we are putting all our effort into fixing synapse's core stability problems and getting the spec to a 1.0 (and synapse to a 1.0) rather than adding new features. So either it needs to be clearly a massive improvement, or we need someone else to step in and review it and benchmark it and make the case for prioritising it. Sorry that it's got stuck for so long :(

[richvdh]

To add to what matthew said: it's not just about shepherding this into synapse. Even if it did make a big improvement, it's rare that something substantial like this lands and immediately integrates perfectly with other software, so we'd have to budget for some time to handle any issues that might come up. I'm very keen that we don't get distracted into bug-fixing of new features rather than stabilising what we have.

[krombel]

Your mentions are valid. I started this websocket project as POC because people were asking for this.
And since then I continued using it on my server - mainly probably because I have developed it.
I opened this PR (and the one in matrix-js-sdk) in the intention to get it merged, but currently I see it as a reference for other people who want to experiment with.
And I am currently updating it from time to time to keep it in a working state.

[binarymaster]

Any updates? This feature might decrease network traffic consumption, so it will utilize low network bandwidth cases better.

Also:

This branch has conflicts that must be resolved

[richvdh]

sadly, given we haven't found time to merge this in 4.5 years, I can't see that situation changing any time soon, so I'm going to go ahead and close it.

[amytimed]

Would like to see this merged