webvirt-novncd and webvirt-socketiod get read-only system directories, no
access to /home and /root, no new privileges, no kernel tunables, modules
or cgroups, and only Unix, IPv4 and IPv6 sockets; socketiod also a private
/tmp. novncd keeps the shared /tmp, where a VM's VNC Unix socket may be.
They keep what they need: a pty and its console worker, TCP and Unix
sockets, ssh with its configuration, writes under /srv/webvirtcloud and
the service user's ~/.ssh. The units installed by the update steps bring
this.
The installer and the manual installation install four systemd units
(webvirt-cloud, webvirt-novncd, webvirt-socketiod, webvirt-worker) that
run as the web server's user with absolute paths and read
/etc/default/webvirtcloud. gunicorn, socketiod and the worker stop with
KillMode=mixed, so they wind down their own children. supervisor, its
installer code and the contributed systemd files go; the README gets
the update, rollback and a one-time move from supervisor, and the
installer refuses to run over a supervisor install. Docker keeps runit;
novncd's runit script is the one-line form of the others.
The xterm console never connected: socketiod expected a different token
format, its worker had no compute credentials, one global console was
shared by every client and its output broadcast to all of them, and the
Docker image did not run socketiod at all.
- console/tokens.py: one authorize() for noVNC and socketiod; the signed
token is the only credential, checked at connect time.
- socketiod: one pty worker per client (consolecallback with the
instance id), one session per VM, a session cap, input and resize
checked; the parent never opens libvirt. The engine.io same-origin
check is on.
- consolecallback: opens the console with the compute's credentials and
exits with a message when it cannot.
- Docker runs socketiod as a runit service; nginx proxies /socket.io/
with Host and the scheme for the origin check. Supervisor and systemd
start it as well; WEBVIRTCLOUD_SERIAL_CONSOLE=1 enables it.
- Tests: token and session unit tests, socketiod as a process, and a
live test that reads SeaBIOS from a wvc-test VM on the TCP and SSH
hosts.
socketiod does not validate the console token, keeps a single global PTY
and broadcasts its output to every connected client, so anyone who can
reach port 6081 can read and write a serial console that someone opened.
It is also broken for legitimate users, since console/views.py now writes
signed tokens that socketiod cannot parse.
Until it is rewritten, turn the serial console off by default:
- Add SERIAL_CONSOLE_ENABLED = False to the settings template; installs
whose settings.py lacks it are treated as disabled.
- The console view shows an error instead of the xterm page for pty
consoles while the setting is off.
- socketiod refuses to start unless SERIAL_CONSOLE_ENABLED is True.
- Supervisor: autostart=false for socketiod; drop -d (debug) from the
supervisor and systemd definitions; fix the systemd unit description;
conf/systemd/install.sh no longer suggests enabling socketiod.
- README: stop opening port 6081 and document how to enable the serial
console on a trusted network.
