Requirements for accessing over an ssh tunnel

[Booklordofthedings]

Im currently attempting to setup cockpit on a debian server so that I can just ssh into the server, tunnel the 9090 port and
use the interface from my local browser.

Loging in is possible, however attempting to get admin rights or switch the tabs in the service view automatically sends me to the reconnect screen.

Im unsure wether this is a bug, not supported as a usecase, or just a misconfiguration on my part.

The version of cockpit im using is 356 with basically no changes to the default configuration.
The only open port on the server is the ssh port.
I have tried the approaches specified In this issue, however they have not actually worked for me.

[jelly]

Port forwarding over SSH should work fine, what Debian version do you run? And is sudo installed on the host?

[Booklordofthedings]

So ive done so debugging and the issue is the call to attach events thats seemingly done for checking the connection

File "/usr/lib/python3/dist-packages/cockpit/channels/dbus.py", line 236, in do_open
                                                              self.bus.attach_event(None, 0)

The call errors with an error code other than busy (22 sd_bus_attach_event: Invalid argument) and causes it to attempt to open the 1:3!3 channel again which then disconnects.

If it stop the code from raising the error further in dbus.py the entire thing works as expected

[Venefilyn]

@Booklordofthedings sounds like a bug, mind creating an issue with reproducer?

[Booklordofthedings]

I assume its just #20150
but ill open one when I get the time

[Booklordofthedings]

Server: Trixie 13 with Kernel Linux 6.12.57+deb13-amd64
Client: Trixie Linux 6.12.73+deb13-amd64
Sudo is installed on both.
The account im logging into is a member of both sudo and wheel

The full output of journalctl during the reconnect error

Mar 09 14:58:55 pelliper /usr/bin/cockpit-bridge[608739]: Exception in callback _Transport._read_ready()
                                                          handle: <Handle _Transport._read_ready()>
                                                          Traceback (most recent call last):
                                                            File "/usr/lib/python3.13/asyncio/events.py", line 89, in _run
                                                              self._context.run(self._callback, *self._args)
                                                              ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                                                            File "/usr/lib/python3/dist-packages/cockpit/transports.py", line 98, in _read_ready
                                                              self._protocol.data_received(data)
                                                              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
                                                            File "/usr/lib/python3/dist-packages/cockpit/protocol.py", line 180, in data_received
                                                              result = self.consume_one_frame(self.buffer)
                                                            File "/usr/lib/python3/dist-packages/cockpit/protocol.py", line 130, in consume_one_frame
                                                              self.frame_received(data[start:end])
                                                              ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
                                                            File "/usr/lib/python3/dist-packages/cockpit/protocol.py", line 84, in frame_received
                                                              self.control_received(data)
                                                              ~~~~~~~~~~~~~~~~~~~~~^^^^^^
                                                            File "/usr/lib/python3/dist-packages/cockpit/protocol.py", line 94, in control_received
                                                              self.channel_control_received(channel, command, message)
                                                              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^
                                                            File "/usr/lib/python3/dist-packages/cockpit/router.py", line 211, in channel_control_received
                                                              endpoint.do_channel_control(channel, command, message)
                                                              ~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^
                                                            File "/usr/lib/python3/dist-packages/cockpit/channel.py", line 154, in do_channel_control
                                                              self.do_control(command, message)
                                                              ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
                                                            File "/usr/lib/python3/dist-packages/cockpit/channel.py", line 132, in do_control
                                                              self.do_open(message)
                                                              ~~~~~~~~~~~~^^^^^^^^^
                                                            File "/usr/lib/python3/dist-packages/cockpit/channels/dbus.py", line 236, in do_open
                                                              self.bus.attach_event(None, 0)
                                                              ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^
                                                            File "/usr/lib/python3/dist-packages/cockpit/_vendor/systemd_ctypes/librarywrapper.py", line 206, in <lambda>
                                                              setattr(cls, name, lambda *args: func(*args))
                                                                                               ~~~~^^^^^^^
                                                            File "/usr/lib/python3/dist-packages/cockpit/_vendor/systemd_ctypes/librarywrapper.py", line 73, in errcheck
                                                              raise OSError(-result, f"{func.__name__}: {os.strerror(-result)}")
                                                          OSError: [Errno 22] sd_bus_attach_event: Invalid argument
Mar 09 14:58:55 pelliper cockpit-session[608739]: Traceback (most recent call last):
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/bin/cockpit-bridge", line 8, in <module>
Mar 09 14:58:55 pelliper cockpit-session[608739]:     sys.exit(main())
Mar 09 14:58:55 pelliper cockpit-session[608739]:              ~~~~^^
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/lib/python3/dist-packages/cockpit/bridge.py", line 340, in main
Mar 09 14:58:55 pelliper cockpit-session[608739]:     run_async(run(args), debug=args.debug)
Mar 09 14:58:55 pelliper cockpit-session[608739]:     ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/lib/python3/dist-packages/cockpit/_vendor/systemd_ctypes/event.py", line 146, in run_async
Mar 09 14:58:55 pelliper cockpit-session[608739]:     asyncio.run(main, debug=debug, loop_factory=selector_event_loop_factory)
Mar 09 14:58:55 pelliper cockpit-session[608739]:     ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/lib/python3.13/asyncio/runners.py", line 195, in run
Mar 09 14:58:55 pelliper cockpit-session[608739]:     return runner.run(main)
Mar 09 14:58:55 pelliper cockpit-session[608739]:            ~~~~~~~~~~^^^^^^
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/lib/python3.13/asyncio/runners.py", line 118, in run
Mar 09 14:58:55 pelliper cockpit-session[608739]:     return self._loop.run_until_complete(task)
Mar 09 14:58:55 pelliper cockpit-session[608739]:            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/lib/python3.13/asyncio/base_events.py", line 725, in run_until_complete
Mar 09 14:58:55 pelliper cockpit-session[608739]:     return future.result()
Mar 09 14:58:55 pelliper cockpit-session[608739]:            ~~~~~~~~~~~~~^^
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/lib/python3/dist-packages/cockpit/bridge.py", line 191, in run
Mar 09 14:58:55 pelliper cockpit-session[608739]:     await router.communicate()
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/lib/python3/dist-packages/cockpit/router.py", line 250, in communicate
Mar 09 14:58:55 pelliper cockpit-session[608739]:     await self._communication_done
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/lib/python3/dist-packages/cockpit/protocol.py", line 180, in data_received
Mar 09 14:58:55 pelliper cockpit-session[608739]:     result = self.consume_one_frame(self.buffer)
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/lib/python3/dist-packages/cockpit/protocol.py", line 130, in consume_one_frame
Mar 09 14:58:55 pelliper cockpit-session[608739]:     self.frame_received(data[start:end])
Mar 09 14:58:55 pelliper cockpit-session[608739]:     ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/lib/python3/dist-packages/cockpit/protocol.py", line 84, in frame_received
Mar 09 14:58:55 pelliper cockpit-session[608739]:     self.control_received(data)
Mar 09 14:58:55 pelliper cockpit-session[608739]:     ~~~~~~~~~~~~~~~~~~~~~^^^^^^
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/lib/python3/dist-packages/cockpit/protocol.py", line 94, in control_received
Mar 09 14:58:55 pelliper cockpit-session[608739]:     self.channel_control_received(channel, command, message)
Mar 09 14:58:55 pelliper cockpit-session[608739]:     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^
Mar 09 14:58:55 pelliper cockpit-session[608739]:   File "/usr/lib/python3/dist-packages/cockpit/router.py", line 192, in channel_control_received
Mar 09 14:58:55 pelliper cockpit-session[608739]:     raise CockpitProtocolError('channel is already open')
Mar 09 14:58:55 pelliper cockpit-session[608739]: cockpit.protocol.CockpitProtocolError: channel is already open
Mar 09 14:58:55 pelliper sudo[608775]: pam_unix(sudo:auth): conversation failed
Mar 09 14:58:55 pelliper sudo[608775]: pam_unix(sudo:auth): auth could not identify password for [book]
Mar 09 14:58:55 pelliper ssh-agent[608735]: exiting on signal 15
Mar 09 14:58:55 pelliper cockpit-session[608729]: pam_unix(cockpit:session): session closed for user book
Mar 09 14:58:55 pelliper systemd-logind[587628]: Session 43823 logged out. Waiting for processes to exit.
Mar 09 14:58:55 pelliper systemd[1]: cockpit-session@117-608565-65109.service: Deactivated successfully.
Mar 09 14:58:55 pelliper systemd[1]: session-43823.scope: Deactivated successfully.
Mar 09 14:58:55 pelliper systemd-logind[587628]: Removed session 43823.

[Booklordofthedings]

Actually the issue isnt specifically because of the ssh tunnel.
Ive tried setting it up via a reverse proxy and the issue still persist.