Websocket Proxy

Proxy between a client and a http2 service.

A client that can not speek http2, for example it is not in an https environment, can use this service to connect to an http2 service.

This is needed, because a browser only creates a very low number of http1.1 connections to a server (firefox and chome create 6 connections). With this service there many long living http connections can be multiplexed via a websocket connection.

Install and Start

With Go

When Go is installed, the service can be installed with:

go get github.com/OpenSlides/openslides-wsproxy/cmd/wsproxy

This command is case sensitive!

After this command, the binary is installed inside the gopath. When the gopath is integrated correctly, the service can be started with:

wsproxy

With Checked out repository and Go

When the repository is checked out, the service can be build and started with

go build ./cmd/wsproxy && ./wsproxy

With Checked out repository and Docker

The repository contains a dockerfile which starts the service

docker build . --tag openslides-wsproxy
docker run -p 9015:9015 openslides-wsproxy

With prebuild docker container

There is a docker container on docker-hub:

docker run -p 9015:9015 ostcar/openslides-wsproxy

Example requests with websocat

To test this service the tool websocat can be used.

OpenSlides 3+

When the service is running, a websocket connection can be created with:

websocat ws://localhost:9015/system/autoupdate

Afterwards it is possible to create connections to the autoupdate service by sending the following command via stdin throw the websocket connection. Make sure not to close stdin or the websockte connection will also be closed.

{"cmd":"connect","id":1,"url":"/system/autoupdate"}

The service will return the data of the http2 connection. Each line of the autoupdate-output will be one websocket frame.

To close a connection, send

{"cmd":"close","id":1}

OpenSlides 4

The command to connect to OpenSlides4 autoupdate service needs a body:

{"cmd":"connect","id":1,"url":"/system/autoupdate","body":[{"ids":[5],"collection":"user","fields":{"name":null}}]}

Environment variables

The service can be configured with the following environment variables:

• WSPROXY_PORT: Port where the service listens on. The default is 9015.
• WSPROXY_HOST: The device where the service starts. The default is am empty string which starts the service on every device.
• AUTOUPDATE_HOST: Host of the autoupdate service. The default is localhost.
• AUTOUPDATE_PORT: Port of the autoupdate service. The default is 8002.
• AUTOUPDATE_PROTOCOL: Protocol of the datastore reader. The default is http.