Unable to connect when using a DNS

[Marty42780]

Explain what happens

1. When I connect in LAN (192.168.0.XX:9000), it works.
2. When I connect in WAN with a domain name, it refuses to login me.

I use the reverse DNS of my other NAS to connect to Cockpit and it automatically adds an SSL certificate

Version of Cockpit

Version 239

Where is the problem in Cockpit?

Networking

Server operating system

Debian

Server operating system version

Debian GNU/Linux 10 (buster) / OpenMediaVault server

What browsers are you using?

Chrome

System log

cockpit-tls[7690]: cockpit-tls: gnutls_handshake failed: A TLS fatal alert has been received.

[martinpitt]

I use the reverse DNS of my other NAS to connect to Cockpit and it automatically adds an SSL certificate

What do you mean by this exactly? Does your NAS provide a reverse proxy which does TLS by itself? Then cockpit-tls should receive a plain HTTP connection, and not attempt a TLS handshake. It will most likely fail to login (as this scenario needs to be configured), but you should see the login page. So I'm afraid I need some more explanation what happens here.

[Marty42780]

Like you said, I have the login page but when I login I have an error.
I use the reverse DNS of my Synology DS to connect to my server (which have Cokpit) from WAN. This reverse DNS automatically add a TLS certificate. The reverse DNS send a http request to cockpit-tls.

[martinpitt]

Ah, that wasn't clear, thanks. For that to work you need to configure cockpit.conf to be aware of the proxy. See e.g. https://github.com/cockpit-project/cockpit/wiki/Proxying-Cockpit-over-NGINX or https://github.com/cockpit-project/cockpit/wiki/Proxying-Cockpit-over-Apache-with-LetsEncrypt how to do that.

[Marty42780]

I will see this thank you. 🙃