[lxc-users] Problems with user sessions inside a Ubuntu Desktop Container

[Jäkel, Guido]

Dear all,

this is my 2nd try to get an "Ubuntu Desktop" container running on a hosting server using "Gentoo" at home. The server is used as a router, media server, audio player. It is used and administrated  "headless" via ssh. But it's hardware is a vanilla PC and now it also should be usable as a workstation, too. Because it is used on two other workstation, the aim is to run Ubuntu (as possible 14.04 LTS).

At turn of the year I got time to do software updates, and now I'm using LXC on/with
 *  linux-4.1.13-gentoo, with all lxc-checkconfig "green"
 *  lxc 1.1.5
 *  lxcfs 0.12

In principle, LXC is working well - I was able to "lxc-create" and successfully start a Container with Ubuntu Trusty (name ubuntu) from the online repositories without noteworthy problems. I was able to "apt update/upgrade", log in via lxc-console and (after installing) sshd. Because it's my own server, I'm currently running it in the privileged mode.

Then, I clone it (named celly) and add 

	lxc.cgroup.devices.allow = c 4:7 rwm    # /dev/tty7 X Desktop
	lxc.cgroup.devices.allow = c 4:8 rwm    # /dev/tty8 X Desktop
	lxc.cgroup.devices.allow = c 4:9 rwm    # /dev/tty9 X Desktop
	lxc.cgroup.devices.allow = c 29:0 rwm   # /dev/fb0/* framebuffer device
	lxc.cgroup.devices.allow = c 226:* rwm  # /dev/dri/* video card devices
	lxc.cgroup.devices.allow = c 13:* rwm   # /dev/input/* input devices

	lxc.mount.entry = /dev/tty7 dev/tty7 none bind,optional,create=file
	lxc.mount.entry = /dev/tty8 dev/tty8 none bind,optional,create=file
	lxc.mount.entry = /dev/tty9 dev/tty9 none bind,optional,create=file
	lxc.mount.entry = /dev/dri dev/dri none bind,optional,create=dir
	lxc.mount.entry = /dev/input dev/input none bind,optional,create=dir
	
to the stock configuration (which starts with lxc.include = /usr/share/lxc/config/ubuntu.common.conf). This is added so far to reach-in "physical access" to the desktop input/output devices. Because the host is used for audio output purposes using pulseaudio, I plan to pass the audio of the container via IP mechanisms, later.

Then I start and log in and 'atp install ubuntu-desktop'. Now - on my 2nd try with recent Kernel and LXC and without fiddling with cgmanager - it almost was ready to start out of the box: It boots on tty7, change to hires-graphics and show the login manager. The mouse was working, but no the keyboard. To get it working, I installed  xserver-xorg-input-kbd  and a  /etc/X11/xorg.conf.d/10-input.conf  with

	Section "ServerFlags"
	        Option "AutoAddDevices" "False"
	EndSection
	
	Section "ServerLayout"
	        Identifier     "Desktop"
	        InputDevice    "Mouse0" "CorePointer"
	        InputDevice    "Keyboard0" "CoreKeyboard"
	EndSection
	
	Section "InputDevice"
	        Identifier "Keyboard0"
	        Driver "kbd"
	        Option "XkbLayout" "de"
	EndSection
	
	Section "InputDevice"
	        Identifier "Mouse0"
	        Driver "mouse"
	        Option "Protocol" "auto"
	        Option "Device" "/dev/input/mice"
	        Option "ZAxisMapping" "4 5 6 7"
	EndSection    


Then, I was able to log in and Unity was starting. First things I want to do was to change some system settings via the GUI. We know, this is asking to authenticate; the same is needed to install software or "update the system" via the GUI. Now, the Dialogs working well, but then there is a dbus error displayed. Using  loginctl  at command line, it turns out that there is a seat, but no user session. It's the same if I log-in via ssh.

	ubuntu at celly:~$ loginctl 
	   SESSION        UID USER             SEAT            
	
	0 sessions listed.


	ubuntu at celly:~$ loginctl list-seats
	SEAT            
	seat0           

	1 seats listed.


Please, give me a hint what is missing or may not running or I should check for, because I'm a server guy and not very familiar with what happens in background on a desktop system. On my first try in last year to get this setup running, there have been more and deeper problems, but this high-level one I noticed, too. Now, it seems that the "Desktop Container" is just a few steps away from being ready for operational tasks.


thank you in advance

Guido