blog/ Configuring Bind9 in a chroot

Every now and then, I move my nameserver to a new machine, and I have to google for the recipe for chrooting it on Debian. So, this time, I'm documenting it here.

The assumption is, you've got an up-to-date Debian machine, running etch. Then:

  1. Install bind9 and its docs and utilities:

     # apt-get install bind9 bind9-doc dnsutils

    It will probably autostart after install, so stop it before proceeding:

     # /etc/init.d/bind9 stop
  2. Create your chroot. This requires a minimal file tree:

     # mkdir -p /var/chroot/bind9/{etc,dev,var/cache/bind,var/run/bind/run}
     # chown -R bind:bind /var/chroot/bind9/var/*

    And some devices:

     # mknod /var/chroot/bind9/dev/null c 1 3
     # mknod /var/chroot/bind9/dev/random c 1 8
     # chmod 666 /var/chroot/bind9/dev/{null,random}
  3. Move your default configuration files:

     # mv /etc/bind /var/chroot/bind9/etc
     # ln -s /var/chroot/bind9/etc/bind /etc/bind
  4. Tell syslog to listen for log events in the chroot:

     # vi /etc/default/syslogd

    and add the line:

     SYSLOGD="-a /var/chroot/bind9/dev/log"
  5. Tell bind9 init to use the chroot:

     # vi /etc/default/bind9

    and add:

     OPTIONS="-u bind -t /var/chroot/bind9"
  6. Restart syslogd and make sure it creates /dev/log in the chroot.

     # /etc/init.d/sysklogd restart
     Restarting system log daemon: syslogd.
     # ls -al /var/chroot/bind9/dev/log
     srw-rw-rw- 1 root root 0 2008-04-12 21:10 /var/chroot/bind9/dev/log
  7. Start bind9 and make sure it works

     # /etc/init.d/bind9 start
     Starting domain name service...: bind.
     # ps ax | grep [n]amed
      5397 ?        Ssl    0:00 /usr/sbin/named -u bind -t /var/chroot/bind9

    # host localhost localhost A

Now, you're done the chroot portion. Copy over your old named.conf.local and db.yourdomain-here files, and restart again.