falcon: Failed to upgrade to WebSocket

I’m hoping I missed an obvious step, and am posting here before I dive in deeper.

Full message here:

Failed to upgrade to WebSocket (REQUEST_METHOD: GET, HTTP_CONNECTION: keep-alive, Upgrade, HTTP_UPGRADE: )
Finished "/cable"[non-WebSocket] for 127.0.0.1 at 2023-03-22 08:37:13 -0600

Context: I’m exploring what it would take (if anything) to support Falcon servers running on fly.io. I started with Demo 3 which you can run on your own machine if you have Rails 7, Docker, Redis, and Postgres installed - simply copy and paste the script into an empty directory.

It starts out with Puma. If you open two browser windows and press refresh a visitor counter will update in both. Simple stuff.

Next, run:

bundle remove puma
bundle add falcon

And restart the server and the websocket fails to start.

In order to debug this, I repeated this with the latest Rails main, which I instrumented with log statements. It seems that websocket_possible? is nil at the following line https://github.com/rails/rails/blob/355fd5929058ee3a73032c5f62de3d8819550482/actioncable/lib/action_cable/connection/base.rb#L75; this in turn is because ::WebSocket::Driver.websocket?(env) is false at https://github.com/rails/rails/blob/355fd5929058ee3a73032c5f62de3d8819550482/actioncable/lib/action_cable/connection/web_socket.rb#L10

About this issue

Original URL
State: closed
Created a year ago
Reactions: 1
Comments: 19 (11 by maintainers)

Commits related to this issue

Expose HTTP_UPGRADE header when translating request to Rack environment. Potential fix for <https://github.com/socketry/falcon/issues/202>. — committed to socketry/protocol-rack by ioquatix 7 months ago
Expose HTTP_UPGRADE header when translating request to Rack environment. Potential fix for <https://github.com/socketry/falcon/issues/202>. — committed to socketry/protocol-rack by ioquatix 7 months ago
Expose HTTP_UPGRADE header when translating request to Rack environment. Potential fix for <https://github.com/socketry/falcon/issues/202>. — committed to socketry/protocol-rack by ioquatix 7 months ago
Expose HTTP_UPGRADE header when translating request to Rack environment. (#8) Potential fix for <https://github.com/socketry/falcon/issues/202>. — committed to socketry/protocol-rack by ioquatix 7 months ago

Most upvoted comments

also running into this now. anyone managed to find out what’s happening?

buhrmi on Sep 4, 2023

Yooo just tuning in to say that adding protocol-rack 0.4.1 to my Gemfile seems to have solved the issue. supercool 👍

buhrmi on Dec 13, 2023

I released v0.4.1 which has the fixes discussed above, except the server will still print the warning which you can ignore.

Thank you ! Now it work like a charm ❤️ I will test further

Pash-tet on Dec 11, 2023

I released v0.4.1 which has the fixes discussed above, except the server will still print the warning which you can ignore.

ioquatix on Dec 11, 2023

Hi! I just ran into this issue as well. If there’s an obvious step, I also missed it, I get the same error.

Kind of weird that ::WebSocket::Driver.websocket? would return false, as it’s super generic and not changed for 9 years:

    def self.websocket?(env)
      connection = env['HTTP_CONNECTION'] || ''
      upgrade    = env['HTTP_UPGRADE']    || ''

      env['REQUEST_METHOD'] == 'GET' and
      connection.downcase.split(/ *, */).include?('upgrade') and
      upgrade.downcase == 'websocket'
    end

Does env get mangled somehow?

tinco on Mar 26, 2023