alp_chroot.sh

#!/bin/sh
# by Jakukyo Friel <weakish@gmail.com> under GPL v2.
# heavily modified by Jeremy Adams for simpler chroot on Apline ppc64le under GPL v2.

# chroot users' group
readonly Members=members
# chroot directory (should be owned and writable only by root)
readonly Chroot=/chroot

## Set up chroot environment
setup_chroot() {
    # prepare chroot group
    groupadd $Members

    # build directory tree
    mkdir $Chroot
    cd $Chroot
    mkdir -p dev/pts proc etc etc/apk lib usr/lib var var/log \
        home bin usr/bin sbin usr/sbin mnt/iso

    # copy files
    cp /etc/localtime etc/
    cp /etc/nsswitch.conf etc/
    cp /etc/resolv.conf etc/
    cp /etc/host.conf etc/
    cp /etc/hosts etc/
    cp /etc/apk/repositories etc/apk/
    touch var/log/lastlog
    touch var/run/utmp
    touch var/log/wtmp

    if [ ! -f /etc/resolv.conf ]; then
      echo "Creating resolv.conf"
      echo "nameserver 8.8.8.8" > etc/resolv.conf
    fi

    # create devices
    mknod dev/urandom c 1 9 && chmod 0666 dev/urandom
    mknod dev/ptmx c 5 2 && chmod 0666 dev/ptmx
    mknod dev/tty c 5 0 && chmod 0666 dev/tty

    # The new environment needs access to terminals (this is necessary for a user to login) and to proc filesystem.
    mount -o bind /dev/pts dev/pts/
    mount -o bind /proc proc/
    
    cd /tmp
    mirror=http://dl-cdn.alpinelinux.org/alpine
    apk_version=2.9.1-r2
    wget ${mirror}/latest-stable/main/ppc64le/apk-tools-static-${apk_version}.apk
    tar -xzf apk-tools-static-*.apk
    ./sbin/apk.static -X ${mirror}/latest-stable/main -U --allow-untrusted --root ${Chroot} --initdb add alpine-base
 
    cd $Chroot    
}


## main function
setup_chroot;