mosh does not work with ssh gateway

[axonasif]

Bug description

Being able to use mosh would be very helpful to overcome latency issues with SSH. I might be able to use it via local-companion but that's too much effort to put each time. Tailscale should also work (nope), but again, that will make the latency even worse.

Steps to reproduce

• Open a workspace
• Run sudo install-packages mosh so that we have mosh server on our workspace
• From gitpod dashboard, copy the ssh address for workspace
• Connect with mosh command from your PC
• See the following screen:

Workspace affected

No response

Expected behavior

No response

Example repository

No response

Anything else?

No response

[loujaybee]

Thanks @axonasif ! Not sure why this doesn't work, but it can be looked into, I dropped the bug tag for now, as not sure it was something we said we'd previously supported (though it would be nice to). Any details, you or others could find when debugging about why it's not connecting would be useful! 🙏

[iQQBot]

I'm afraid there's no way around this. mosh expects the ssh server to be on the public network, or at least the firewall to be able to directly penetrate the specified UDP port, but that's not possible in gitpod

[mrzarquon]

you can get around the UDP limitation using tailscale, but since we don't support tailscale ssh on the workspace, you end using a gitpod ssh gateway session to start the mosh-server but then connect the mosh-client via the tailscale IP / port / session token