Cloudflare blocking Websockets - "Failed to upgrade connection"

[yudai]

Cloudflare blocking Websockets - "Failed to upgrade connection"

[haliphax]

Do you have a proxy sitting in front of GoTTY, or is it raw? Just curious, since I was having this issue, as well, but fixed it with some nginx configuration settings. Of course, I was constantly experiencing the error -- it wasn't intermittent.

[yudai]

Is that possible to provide the command you ran?
If you are using a proxy as @haliphax mentioned, let me know that too.

[carstenhag]

I ran both gotty htop -p "8080" and the one to start gotty with tmux from
the readme.

Nginx is running on the machine but gotty is not getting proxied by it.

Is that possible to provide the command you ran?
If you are using a proxy as @haliphax https://github.com/haliphax
mentioned, let me know that too.

[yudai]

Thanks. Unfortunately, I have no idea about what's the cause but it's a websocket related issue.

[carstenhag]

@yudai Ooh, I think I got the cause of this now. It's probably caused by Cloudflare. I have it only running on @ and only there it doesn't work. Tested on both Chrome and Firefox.

http://92.222.74.40:8080/ OK
http://znc.moter8.xyz:8080/ OK
http://moter8.xyz:8080/ KO

[carstenhag]

https://support.cloudflare.com/hc/en-us/articles/200169466-Can-I-use-CloudFlare-with-websockets-

WebSockets are currently only available for Enterprise customers, but will be available for other plan levels in the future.

All other customers -- Business, Pro, and Free -- should create a subdomain for Websockets in their CloudFlare DNS and disable the CloudFlare proxy ("grey cloud" the record in CloudFlare DNS Settings).

[k0l0r3k99]

I tcpdumped traffic before CloudFlare and after CloudFlare. CF removes only "Upgrade: websocket", other data are unchanged. Could gotty ignore "Upgrade: websocket"? Another way to fix is use nginx proxy and add header with upgrade.

Edit: use nginx doesn't resolve this. I've error: "Failed to authenticate websocket connection: websocket: close 1006 unexpected EOF". In JS, new WebSocket("wss://cloudflare/gotty/ws").onOpen is not called.

[rajeget]

For NGINX please see my page https://github.com/rajeget/websocket-nginx/ , it works

Let me know if that works for cloudfare as well .