• Posts
  • RSS
  • ◂◂RSS
  • Contact

  • 32-bit Chroots on Ubuntu LTS 12 and Centos 5

    July 22nd, 2016
    tech
    Because operating systems are generally backwards compatible, to build binaries that work on several versions of Linux it's best to build them on the oldest version of the OS that's still supported. For Ubuntu this is currently LTS 12, and for CentOS it's 5. While I can get a VM for either of these on Rackspace etc, at this point I can only get 64-bit versions and some people still need 32-bit binaries. So, here's how to make a 32-bit chroot environment for building them.

    Ubuntu
    Derived from jblevins.org/log/ubuntu-chroot.

    $ sudo apt-get install debootstrap dchroot
    $ sudo emacs /etc/schroot/schroot.conf
    [precise_i386]
    description=Ubuntu 12.04 Precise for i386
    directory=/var/chroot/precise_i386
    personality=linux32
    root-users=buildbot
    users=buildbot
    
    $ sudo emacs /etc/schroot/mount-defaults
    comment out the /home line (Cross-mounting
    /home makes moving files much easier.)
    $ sudo debootstrap --variant=buildd --arch i386 precise
    /var/chroot/precise_i386 http://archive.ubuntu.com/ubuntu/
    $ sudo cp /etc/resolv.conf /var/chroot/precise_i386/etc/resolv.conf
    $ sudo cp /etc/apt/sources.list /var/chroot/precise_i386/etc/apt/
    $ pushd /var/chroot/precise_i386/etc
    $ for x in passwd shadow group gshadow hosts sudoers; do
        sudo rm $x; sudo ln /etc/$x;
    done
    $ popd
    $ sudo emacs /etc/fstab
    add:
    /dev /var/chroot/precise_i386/dev none bind 0 0
    proc-chroot /var/chroot/precise_i386/proc proc defaults 0 0
    devpts-chroot /var/chroot/precise_i386/dev/pts devpts defaults 0 0
    none /var/chroot/precise_i386/dev/shm tmpfs rw,nosuid,nodev,noexec 0 0
    $ sudo mount -a
    $ sudo chroot /var/chroot/precise_i386/
    # apt-get update
    # apt-get install gnupg locales dialog emacs wget
    # locale-gen en_US.UTF-8
    # dpkg-reconfigure tzdata
    # dpkg-reconfigure passwd
    # apt-get install sudo
    # mkdir /home/buildbot
    # chown buildbot /home/buildbot
    # exit
    $ sudo emacs /var/chroot/precise_i386/etc/debian_chroot
    precise_i386
    $ schroot -c precise_i386
    now you're in the chroot
    
    CentOS
    I wish there was debootstrap for CentOS.

    $ sudo yum install setarch
    $ sudo mkdir -p /var/chroot/centos_i386/var/lib/rpm \
                    /var/chroot/centos_i386/home/buildbot
    $ sudo cp /etc/rpm/platform  /etc/rpm/platform.real
    $ echo i686-redhat-linux | sudo tee /etc/rpm/platform
    $ sudo rpm --rebuilddb --root=/var/chroot/centos_i386
    $ URL="http://mirror.centos.org/centos/5/os/i386/"
    $ URL+="CentOS/centos-release-5-10.el5.centos.i386.rpm"
    $ wget "$URL"
    $ sudo rpm --root=/var/chroot/centos_i386 --nodeps -i \
           centos-release-5-10.el5.centos.i386.rpm
    $ sudo yum --installroot=/var/chroot/centos_i386/ update
    $ sudo yum --installroot=/var/chroot/centos_i386/ install \
               -y rpm-build yum
    $ sudo mv /etc/rpm/platform.real  /etc/rpm/platform
    $ sudo cp /etc/resolv.conf /var/chroot/centos_i386/etc/resolv.conf
    $ pushd /var/chroot/centos_i386/etc
    $ sudo rm group passwd
    $ for x in passwd shadow group gshadow hosts sudoers; do
        sudo ln /etc/$x;
    done
    $ popd
    (All these mounts should really be put into /etc/fstab.)
    $ sudo mount -t proc proc /var/chroot/centos_i386/proc
    $ sudo mount -t sysfs none /var/chroot/centos_i386/sys
    $ sudo mount --bind /dev /var/chroot/centos_i386/dev
    $ sudo mount -t tmpfs tmpfs /var/chroot/centos_i386/dev/shm
    $ sudo mount --rbind /selinux /var/chroot/centos_i386/selinux
    $ sudo mount --rbind /etc/selinux \
           /var/chroot/centos_i386/etc/selinux
    $ sudo mount --rbind /home/buildbot \
           /var/chroot/centos_i386/home/buildbot
    $ sudo setarch i386 /usr/sbin/chroot \
           /var/chroot/centos_i386/ /bin/bash -l
    # rm /var/lib/rpm/__db.00*
    now you're in the chroot
    

    Comment via: google plus

    Recent posts on blogs I like:

    A Big Problem With The Going To Bed Book

    One day my dad was reading this book called the "Going to Bed Book" to my sister Nora. The book is basically about a bunch of animals who are getting ready for bed on a boat. They go down the stairs, take a bath, hang their towels on the wall, find…

    via Lily Wise's Blog Posts September 18, 2023

    Investing in boundaries with young kids

    Putting in some work to get the behavior you want The post Investing in boundaries with young kids appeared first on Otherwise.

    via Otherwise August 15, 2023

    Self-driving car bets

    This month I lost a bunch of bets. Back in early 2016 I bet at even odds that self-driving ride sharing would be available in 10 US cities by July 2023. Then I made similar bets a dozen times because everyone disagreed with me. The first deployment to pot…

    via The sideways view July 29, 2023

    more     (via openring)


  • Posts
  • RSS
  • ◂◂RSS
  • Contact