Rails 5 ActionCable WebSockets is not returning upgrade headers with status 101 Upgrade response

Question

EDIT: Shown at end, found that upgrade headers were actually created.

I\'m working from the action-cable-example codebase, trying to build a WebSocket app. The \"Ch

Answer 1

The problem was that I was trying to use the Thin server in development. It would operate. However, it was actually transmitting the response headers during its processing, such as this:

Response Headers
Connection:keep-alive
Server:thin

ActionCable was actually sending the appropriate upgrade headers, but it was doing so only after Thin had sent out its own headers so the client didn't recognize them.

After converting back to Puma, I receive these as expected:

Response Headers
HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: XJOmp1e2IwQIMk5n0JV/RZZSIhs=