use a websocket reverse proxy to relay OCPP messages to multiple backends

[scruysberghs]

As stated in the title. I have a charging station that can only talk to one OCPP backend. I need it to be able to connect to a cloud based OCPP backend for invoicing etc but also want to control it locally trough the OCPP integration in Home Assistant. Has anybody looked at putting a reverse proxy (nginx of Caddy or...) in between that you can set as endpoint in the charging station and relays messages both ways? Has this bee done before?

[rsyrnicki]

I don't think that's possible. You would to maintain a connection to two backends at the same time. AFAIK websockets doesn't support that.

[scruysberghs]

I've started working on a small HA addon to do this. It will take a websocket connection from the charging station (CS) and relay messages to multiple backends (configurable from the UI) and also relay reply's from the backends to the CS. It uses MQTT in the middle to handle message mapping and allow for multiple charging stations talking to multiple backends in the future.
Still a work in progress but let me know if you want to help test/debug.

[rsyrnicki]

If you have some success then I'd like to test it.

[scruysberghs]

I stoped working on the extra in between service. Makes more sense to add it to this existing ha ocpp integration. Adding extra config options to optionaly relay messages from and to another central system (local or in the cloud). So 3 features we are working on:

• forwarding messages to secondary central system
• adding support for charging stations with multiple connectors
• adding support to add multiple charging stations to one ha ocpp central system