Ubuntu 18-04 : no veyon service when user logs in



  • Hi

    The issue happens with Ubuntu mate 18-04, Veyon installed from ppa (4.1.7-1)

    The problem is :
    In veyon master, I can see the client PCs when no user is logged (I see lightdm login screen, and I can take control of the PC).
    But as soon as a user logs in on client, computer becomes "red" in veyon-master, and I can't connect to it anymore.

    Below are some informations about tests I did, in case they could be usefull :

    Result for "ps aux | grep veyon" on PC, before a user logs in :

    root      2313  1.6  0.6 370832 27004 ?        Ssl  10:20   0:00 /usr/bin/veyon-service
    root      2531  0.5  0.7 376180 31304 ?        Sl   10:20   0:00 /usr/bin/veyon-server
    lightdm   2533  1.3  0.7 513528 32000 ?        Sl   10:20   0:00 /usr/bin/veyon-worker {8e997d84-ebb9-430f-8f72-d45d9821963d}
    

    Result for "ps aux | grep veyon" on PC, after testuser has logged in :

    root      2313  0.5  0.6 370832 27008 ?        Ssl  10:20   0:00 /usr/bin/veyon-service
    testuser  2814  1.6  1.1 736420 47364 ?        Sl   10:22   0:00 /usr/bin/veyon-worker {8e997d84-ebb9-430f-8f72-d45d9821963d}
    

    Of course, I add a veyon-svc.desktop file in /etc/xdg/autostart/, which launches veyon-ctl service start.
    I got popup windows (2 or 3) at session start, asking for root password. Typing the root password didn't change anything.

    I tried to add those lines in /etc/sudoers too ("Etudiants" and "Utilisateurs" are LDAP groups containing all my users) :

    Cmnd_Alias VEYON_CMDS = /usr/bin/veyon-server start, /usr/bin/veyon-ctl service start, /usr/bin/veyon-service -quiet -startservice
    %Etudiants ALL=(ALL) NOPASSWD: VEYON_CMDS
    %Utilisateurs ALL=(ALL) NOPASSWD: VEYON_CMDS
    

    Nothing changes ( in fact, the only change was I only got one popup window for root password)

    I tried to use command line in user session to see what it did :

    Result for sudo veyon-ctl service start :

    QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
    No protocol specified
    qt.qpa.screen: QXcbConnection: Could not connect to display :0.0
    Could not connect to any X display.
    

    Result for : sudo /usr/bin/veyon-service -quiet -startservice :

    2019-03-26T11:27:16.167: [WARN] Environment for session "/org/freedesktop/login1/session/c4" not yet available - retrying in 1000 msecs
    

    (looping message)

    Just for the record : I'm not new to Veyon : I already use it with ubuntu 16-04 and .deb veyon 4.0.4 package, and in other Win10 rooms. They work fine.

    Have you got a solution for me ?

    Thanks for your job
    ET



  • Hi,

    Waiting for an answer, I red these pages :
    https://veyon.io/blog/2018/04/09/systemd-support/
    https://github.com/veyon/veyon/issues/305

    I adapted my installation method/configuration, but always the same issue (I tried veyon_4.1.91-ubuntu-bionic_amd64.deb too).

    On the blog page (which, I'm conscient, is a little bit "old"), you talk about veyon-server and veyon-service, but nothing about this veyon-worker I can see in 'ps aux' when a user logs in.

    But what I can see, is that veyon server disappears from processes list when a user is looged in (probably the cause for the issue).

    Can anybody tell me if he managed to get veyon working with ubuntu 18-04 ? I'm preparing my room's configuration for next academic year, and I really need to know if I can count on veyon or not.
    I must confess, I'm a little bit worried 😞

    Thanks
    ET



  • A little precision (maybe useful ?) :

    It seems to work fine for lightdm user :
    As we can see in my previous posts, when PCs are on login screen (no user logged in), we can see three processes :

    root      2313  1.6  0.6 370832 27004 ?        Ssl  10:20   0:00 /usr/bin/veyon-service
    root      2531  0.5  0.7 376180 31304 ?        Sl   10:20   0:00 /usr/bin/veyon-server
    lightdm   2533  1.3  0.7 513528 32000 ?        Sl   10:20   0:00 /usr/bin/veyon-worker {8e997d84-ebb9-430f-8f72-d45d9821963d}
    

    I suppose it's exactly what we should see with a logged user.
    If I try

    service veyon-service start
    

    In my user session, it asks for root password.



  • OK,

    I finally found where the issue comes from :

    My users home directory are on an NFS server. The local root account has no rights on their home.
    I suppose veyon tries to write something in user's home, and that's why it fails starting service.

    Could you give me some details about this, so I could try to find a way to make it work ?

    Thanks
    ET



  • Hi,

    I will stop discussion on this post, as the problem is "resolved".
    But I'l make a new one about NFS, because I really need to get informations about this to make it work in my rooms

    ET



  • Sorry for the confusion. Even though the figures at http://docs.veyon.io/en/latest/admin/introduction.html#components are outdated the information below are up to date and should give you an idea of the involved processes. Do you still have questions regarding the processes?


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