Auto-reconnection support in websockets

lorenzodonini commented 3 years ago

Implements auto-reconnect behavior for client websockets, as requested in https://github.com/lorenzodonini/ocpp-go/issues/38.

Implementation details

Client auto-reconnect behavior is triggered by default upon:
- timeouts
- connection errors
User-initiated disconnects will NOT trigger auto-reconnection
Auto-reconnect delays may be set via ClientTimeoutConfig
SetDisconnectedHandler and SetReconnectedHandler allow to register handlers for being notified of the respective events

Known Issues

This new feature only affects the websocket package and is not yet fully integrated by the ocpp-j package.

The OCPP library will work as before, but upon reconnection, no retransmissions are triggered and no pending requests are cancelled. This will be tackled in a future PR.

Connection tests

Tests for network errors were added, to simulate connection drops.

Toxiproxy is being used as a service for this purpose.

lorenzodonini commented 3 years ago

@andig feel free to have a look at this, if you want.

I'll be working on integrating this properly with the ocpp-j layer and add some further improvements on a separate branch.

andig commented 3 years ago

feel free to have a look at this, if you want.

I just glanced over it but didn't try. From the comments you can see that I did not entirely grasp how you've designed this to work, please feel free to ignore the comments if not relevant.

lorenzodonini commented 3 years ago

feel free to have a look at this, if you want.

I just glanced over it but didn't try. From the comments you can see that I did not entirely grasp how you've designed this to work, please feel free to ignore the comments if not relevant.

Feedback is always appreciated :) Pushed some changes already. If something is still unclear, let me know

lorenzodonini / ocpp-go