405 Method Not Allowed with websocket geth RPC

Question

curl -i -N -H "Connection: Upgrade" -H "Upgrade: websocket" -H "Host: XXXXXXX" -H "Origin: https://XXXXXXX/" -H "Content-Type: application/json" -X POST --data '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}' https://XXXXXXX/
HTTP/2 405 
server: nginx/1.18.0
date: Fri, 26 Feb 2021 13:56:20 GMT
content-type: text/plain; charset=utf-8
content-length: 19
sec-websocket-version: 13
x-content-type-options: nosniff

Method Not Allowed

geth is running with websockets enabled with the following settings: --ws --ws.port 8546 --ws.api eth,net,web3 --ws.origins '*' --ws.addr 0.0.0.0 and is behind an nginx reverse proxy:

    location / {
        proxy_http_version 1.1;
        proxy_set_header Upgrade "websocket"; # $http_upgrade;
        proxy_set_header Connection "upgrade"; # $connection_upgrade;
        proxy_set_header Host $http_host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_pass http://XXXXXX;
    }

I have also tried eth version command, same result. Same error when I connect to the websocket directly, not through nginx.

Answer 1

OK, the issue is that several guides on how to connect to websockets using Curl don't work on geth's websocket for whatever reason. Using a tool specifically for websockets allowed the requests to go through just fine.

$ wscat -c wss://XXXXXXXXXX/
connected (press CTRL+C to quit)
> {"jsonrpc":"2.0","method":"web3_sha3","params":["0x68656c6c6f20776f726c64"],"id":64}
< {"jsonrpc":"2.0","id":64,"result":"0x47173285a8d7341e5e972fc677286384f802f8ef42a5ec5f03bbfa254cb01fad"}