Running Chrooted SVN on Debian Mini-HOWTO
Chapter 4 - Launching chrooted Subversion

We create the dedicated user and group svn and we change the permissions of our repository accordingly :

     $ adduser --system --no-create-home --group svn
     $ chown -R svn.svn /var/jails/svn/var/lib/svn

Then, we write the initialization script for launching the Subversion server into the file /etc/init.d/svn. I've used the file /etc/init.d/skeleton as a template and read the man page of start-stop-daemon(8) to find all the needed options :

     #! /bin/sh
     
     DAEMON=/usr/bin/svnserve
     NAME=svn
     DESC="SVN Server"
     OPTS="--daemon --threads --listen-port=3690 --root=/var/lib/svn"
     CHROOT="/var/jails/svn"
     USER=svn
     GROUP=svn
     
     test -x $DAEMON || exit 0
     
     set -e
     
     case "$1" in
         start)
             echo -n "Starting $DESC: $NAME"
             start-stop-daemon --start --quiet \
                 --user $USER --chuid $USER:$GROUP \
                 --chroot $CHROOT \
                 --startas $DAEMON -- $OPTS
             echo "."
             ;;
         stop)
             echo -n "Stopping $DESC: $NAME"
             start-stop-daemon --stop --quiet \
                 --user $USER \
                 --startas $DAEMON
             echo "."
             ;;
         restart)
             echo -n "Restarting $DESC: $NAME"
             start-stop-daemon --stop --quiet \
                 --user $USER \
                 --startas $DAEMON \
                 --oknodo
             sleep 1
             start-stop-daemon --start  \
                 --user $USER --chuid $USER:$GROUP \
                 --chroot $CHROOT \
                 --startas $DAEMON -- $OPTS
             echo "."
             ;;
         *)
             N=/etc/init.d/$NAME
             echo "Usage: $N {start|stop|restart}" >&2
             exit 1
             ;;
     esac
     
     exit 0

As you can see, I use the --chroot option to specify the location of the jail under which the process will chroot. The --chuid option allows us to run the Subversion server under the svn user and group.

We can test the script typing :

     $ /etc/init.d/svn start
     Starting SVN Server: svn.
     $ /etc/init.d/svn stop
     Stopping SVN Server: svn.
     $ /etc/init.d/svn restart
     Restarting SVN Server: svn.

The only thing left to do is to automate the launching of the server on the booting process of the machine. For this, I use a Debian utilitary program called update-rc.d. This program builds all the links for all the required runlevels :

     $ update-rc.d svn defaults

To test it, I reboot the machine and check the process information :

     $ shutdown -r now
     $ ps -Ao "%p %y %x %U %c" | grep svn
     24358 ?        00:00:00 svn      svnserve
     $ ls -la /proc/24358
     total 0
     dr-xr-x---    3 svn      uucp            0 Feb 15 22:15 .
     dr-xr-xr-x   44 root     root            0 Feb 15 05:31 ..
     -r--r--r--    1 svn      uucp            0 Feb 15 22:15 cmdline
     -r--r--r--    1 svn      uucp            0 Feb 15 22:15 cpu
     lrwxrwxrwx    1 svn      uucp            0 Feb 15 22:15 cwd -> /var/jails/svn
     -r--------    1 svn      uucp            0 Feb 15 22:15 environ
     lrwxrwxrwx    1 svn      uucp            0 Feb 15 22:15 exe -> /var/jails/svn/usr/bin/svnserve
     dr-x------    2 svn      uucp            0 Feb 15 22:15 fd
     -r--r--r--    1 svn      uucp            0 Feb 15 22:15 maps
     -rw-------    1 svn      uucp            0 Feb 15 22:15 mem
     lrwxrwxrwx    1 svn      uucp            0 Feb 15 22:15 root -> /var/jails/svn
     -r--r--r--    1 svn      uucp            0 Feb 15 22:15 stat
     -r--r--r--    1 svn      uucp            0 Feb 15 22:15 statm
     -r--r--r--    1 svn      uucp            0 Feb 15 22:15 status

We can see that the process svnserve is running under svn user with a root pointing to /var/jails/svn.

Mission accomplished!

Running Chrooted SVN on Debian Mini-HOWTO