eventlet is in maintenance mode. socketiod now runs python-socketio in
threading mode under gunicorn (one gthread worker, which holds the
sessions), with simple-websocket, already a python-engineio dependency.
gunicorn waits 1 s on stop: an open console never finishes, and its
worker ends when the pty closes. The forward loop waits in select
instead of polling, and a stopped worker is reaped by a blocking
waitpid. eventlet leaves the requirements.
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.
When the serial console process exited on its own (a bad token, an
unreachable host, a killed consolecallback), the read task died on EIO
while fd and child_pid stayed set: the child was a zombie and every later
connection wrote to the dead pty until socketiod was restarted. A child
that failed before exec also returned into the server code and sent its
traceback to the client.
Now the read loop treats EOF/EIO as the end: it reaps the child, closes
the pty, tells the clients "[console closed]" and disconnects them, so
the next connection starts a new console. The child always leaves with
os._exit, also without a token; output is decoded incrementally, and the
unused imports are gone.
The web app (wsgi.py), novncd and socketiod set SIGCHLD to SIG_IGN at
import. The kernel then reaps every child at once, so subprocess loses
the exit status and a failing command reports 0, in the server and in
anything else run in that process: the test suite had to reset the
signal in two tests.
It was added in 2023 against one defunct bash per gunicorn worker and
per novncd. That bash came from the settings template of the time,
which ran .dec_ldap_pwd.sh with Popen and never waited for it; the
template stopped doing that in 561fedf. A settings.py still holding
that line leaves at most one zombie per process, not a growing number.
- wsgi.py, novncd, socketiod: the global SIG_IGN is removed. subprocess
reaps its own children, websockify installs its own SIGCHLD reaper
for novncd's connection processes, and novncd's SSH tunnels wait for
their ssh process.
- socketiod: the pty child execs consolecallback instead of running it
and then returning into the server's code; disconnect reaps that
child (waitpid) instead of any child (wait).
- The settings template drops its unused subprocess import; the two
test workarounds are removed.
New tests load the web app and novncd in a fresh interpreter and check
that SIGCHLD is untouched and a failing command still returns 1; both
fail on the previous code. A patched novncd in the test container
served five connections and left no child behind.
Comments, docstrings and live test names cited item IDs of a roadmap
that is not part of the repository. They now say what is meant, or
nothing where the sentence stands without them. Test assertions and
behavior are unchanged.
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.
