[lxc-users] jenkins init script and lxc

[Ivan Ogai]

Hello lxc user list,

first of all thanks for lxc, which is amazing.

When installing Jenkins from its official apt-repositoty in Ubuntu
14.04, a user 'jenkins' and an init script are created.

We have followed Stéphane Graber's blog for the user jenkins to be able
to create unprivilaged containers, which works fine.

However, when restarting Jenkins (e.g. from the web interface), the
Jenkins' jobs are no longer able to create containers:

    + lxc-create -t download -n grical -- -d ubuntu -r trusty -a amd64
    lxc-create: utils.c: mkdir_p: 202 Permission denied - failed to create directory '/run/user/0/lxc/'
    failed to create lock
    System error loading container

Rebooting the whole server solves it, but we would like to understand
how to avoid a reboot after a restart of Jenkins.

I guess the problem is how the official init script of Jenkins starts
itself.  In /etc/init.d/jenkins:

    SU=/bin/su
    ...
    # --user in daemon doesn't prepare environment variables like HOME, USER, LOGNAME or USERNAME,
    # so we let su do so for us now
    $SU -l $JENKINS_USER --shell=/bin/bash -c "$DAEMON $DAEMON_ARGS -- $JAVA $JAVA_ARGS -jar $JENKINS_WAR $JENKINS_ARGS" || return 2

How would you recommend to solve the issue?

Internet is full of people having similar problems, and some tell you
how to use some obscure and mysterious cgm commands to solve them. All
complain however that there is no introductory place to understand what
these cgm commands really do.
Is there any FAQ or other resource to easily understand the
basics of cgroups with lxc and related implications when using
subshells, su, and init scripts?

Kind regards,
--
Ivan F. Villanueva
https://timefyme.com
--
Vorgründungsgesellschaft GridMind
Ivan Fernando Villanueva Barrio EU
--
Malmöer Str. 6
10439 Berlin
Germany
--
Tel: +49 30  398 20 596
Fax: +49 30  340 60 473