Root shell
A root terminal on any machine in the instance, for an admin, with no SSH port open.
Servers → Open a root shell on a row opens a terminal on that machine as root — the same as signing in over SSH, with its own files, services and Docker.
cubeship server shell control-plane
cubeship server shell eu-1Who can open one
Only an admin, with a key that is not restricted. No role reaches it: a root prompt on the host is everything the instance is.
From the dashboard it asks for your password again before it opens — a signed-in browser proves somebody signed in once, and this proves they are still the one at the keyboard. The CLI's API key is its own proof.
On a worker
The worker is told to open the shell on its next poll and connects the session back to the control plane, so a worker still publishes no port. A worker that is offline, or on a version of Cubeship from before shells, is refused at once rather than after a wait.
What it is, underneath
A short-lived privileged container in the host's namespaces — the same way Cubeship already edits the host's firewall. It is removed when the session ends. Every session is in the audit log; what is typed is not.