Test a WebSocket using curl.

curl-websocket.sh

curl --include \
     --no-buffer \
     --header "Connection: Upgrade" \
     --header "Upgrade: websocket" \
     --header "Host: example.com:80" \
     --header "Origin: http://example.com:80" \
     --header "Sec-WebSocket-Key: SGVsbG8sIHdvcmxkIQ==" \
     --header "Sec-WebSocket-Version: 13" \
     http://example.com:80/

1. You need to use HTTP/1.1
2. You have specified too few headers

$ curl --http1.1 -i -N -H 'Sec-Websocket-Version: 13' -H 'Sec-Websocket-Key: QUo86XL2bHszCCpigvKqHg==' -H "Connection: Upgrade" -H "Upgrade: websocket" -H "Host: echo.websocket.org" -H "Origin: https://www.websocket.org" https://echo.websocket.org
HTTP/1.1 101 Switching Protocols
upgrade: websocket
connection: Upgrade
sec-websocket-accept: 8dlVwoWynsF/RauFo6HjkWl7dLk=
date: Thu, 25 Apr 2024 14:28:01 GMT
server: Fly/610c12e9 (2024-04-23)
via: 1.1 fly.io
fly-request-id: 01HWATFYXA0Y3STERG1SCHNQS2-ams

 Request served by 7811941c69e658

Thanks @vi that worked perfectly!

I recommend adding --http1.1 to your curl command. The Connection and Upgrade headers are not valid in http/2 and curl will use http/2 if your server supports it.

I lost a few hours trying to figure out why these headers were disappearing when debugging my httpd web socket rewrite rules for the first time.

You saved my life haha. I wasted so much time thinking my move to E2EE was the issue but stupid ActionCable and AWS Target Group using HTTP/2 was the issue! 🤦

Time to look into AnyCable or something else. Thank you!