This page describes the preliminary requirements and design for asynchronous event support in the NDS Labs Workbench. In order to update the GUI in real time, the server needs to send state changes back to the client. This can be achieved via WebSockets, HTTP Long Polling, or HTTP Streaming.
Platforms
We need to decide which browsers and versions we will support going forward. Browser support options might preclude use of some technologies.
Use case
Project A administrator logs in to workbench. Project B admin logs in to workbench along with a second user in another Project B session. When the cluster admin adds a new service, all three sessions are notified. When Project B user 1 adds a stack, Project B user 2's interface is updated.
Events
Project-specific
- Add/update/delete
- Stack
- Volume
- Project
- Status
- Stack
- Stack service
- Error
System-wide:
- Add/update/delete service spec
- Broadcast messages
Message formats
Messages will be sent in JSON format, something like:
{
event: "<ID>",
data: ...
}
Messages will include
- Errors
- Create
- Update
- Delete
- Status
Authentication
References
https://en.wikipedia.org/wiki/WebSocket
https://tools.ietf.org/html/rfc6455
https://devcenter.heroku.com/articles/websocket-security
https://devcenter.heroku.com/articles/websockets
https://devcenter.heroku.com/articles/go-websockets