How to set up a chroot environment for testing

Recently I have suffered a total system destruction in one of my computers. It happened while I was testing a software that I am developing, due to a simple bug. It helped me realize my lack of caution while testing unstable things, and I learned that it is always better to do the testing inside a chroot environment. Chroot’s provide isolation from the rest of the operating system, so that in case of severe errors damage can be mitigated.



Here are the steps that I took for installing a chroot environment for testing.

• Install the packages debootstrap and dchroot:

  sudo apt-get install debootstrap dchroot
  

• Add these line to /etc/schroot/schroot.conf:

  [precise]
  description=Ubuntu Precise LTS
  location=/var/chroot/btranslator
  priority=3
  users=ubuntu
  groups=sbuild
  root-groups=root
  

• Bootstrap the chroot with a minimal Ubuntu installation:

  debootstrap --variant=minbase --arch=amd64 precise \
      /var/chroot/btranslator http://mirror.rackspace.com/ubuntu/
  cp /etc/resolv.conf /var/chroot/btranslator/etc/resolv.conf
  cp /etc/apt/sources.list /var/chroot/btranslator/etc/apt/
  mount -o bind /proc /var/chroot/btranslator/proc
  chroot /var/chroot/btranslator/
  
  apt-get install ubuntu-minimal
  apt-get update
  apt-get upgrade
  apt-get install language-pack-en-base
  apt-get install vim aptitude
  

• Install LAMP:

  apt-get install aptitude tasksel
  tasksel install lamp-server
  

• Make a startup script /etc/init.d/chroot-btranslator with a content like this:

  CHROOT=/var/chroot/btranslator
  
  case "$1" in
    start)
      service apache2 stop
      service mysql stop
  
      mount -o bind /proc $CHROOT/proc
      mount -o bind /dev $CHROOT/dev
      mount -o bind /sys $CHROOT/sys
      mount -o bind /dev/pts $CHROOT/dev/pts
  
      chroot $CHROOT/  service mysql start
      chroot $CHROOT/  service apache2 start
      ;;
  
    stop)
      chroot $CHROOT/  service apache2 stop
      chroot $CHROOT/  service mysql stop
  
      umount $CHROOT/dev/pts
      umount $CHROOT/sys
      umount $CHROOT/dev
      umount $CHROOT/proc
  
      service mysql start
      service apache2 start
      ;;
  esac
  

• Make it executable and start it at boot:

  chmod +x /etc/init.d/chroot-btranslator
  update-rc.d chroot-btranslator defaults
  service chroot-btranslator start
  

Referencies:

• http://joshrendek.com/2013/01/securing-ubuntu/#chroot

Date: 2013-02-14 21:31:49 CET

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