Add the setup-chroot.sh script

The setup-chroot.sh script is very handy for building the server in a
chroot environment. I thought I would share it here in case anyone else
finds it useful.

qa/setup-chroot.sh

@@ -0,0 +1,65 @@
+#!/bin/bash
+
+die() {
+        echo ${@}
+        exit 1
+}
+
+usage()
+{
+        cat << EOF
+$0: sets up a chroot environment for building the ceph server
+usage:
+-h                      Show this message
+
+-r [install_dir]        location of the root filesystem to install to
+                        example: -r /images/sepia/
+
+-s [src_dir]            location of the directory with the source code
+                        example: -s ./src/ceph
+EOF
+}
+
+cleanup() {
+        umount -l "${INSTALL_DIR}/mnt/tmp"
+        umount -l "${INSTALL_DIR}/proc"
+        umount -l "${INSTALL_DIR}/sys"
+}
+
+INSTALL_DIR=
+SRC_DIR=
+while getopts “hr:s:” OPTION; do
+        case $OPTION in
+        h) usage; exit 1 ;;
+        r) INSTALL_DIR=$OPTARG ;;
+        s) SRC_DIR=$OPTARG ;;
+        ?) usage; exit
+        ;;
+        esac
+done
+
+[ $EUID -eq 0 ] || die "This script uses chroot, which requires root permissions."
+
+[ -d "${INSTALL_DIR}" ] || die "No such directory as '${INSTALL_DIR}'. \
+You must specify an install directory with -r"
+
+[ -d "${SRC_DIR}" ] || die "no such directory as '${SRC_DIR}'. \
+You must specify a source directory with -s"
+
+readlink -f ${SRC_DIR} || die "readlink failed on ${SRC_DIR}"
+ABS_SRC_DIR=`readlink -f ${SRC_DIR}`
+
+trap cleanup INT TERM EXIT
+
+mount --bind "${ABS_SRC_DIR}" "${INSTALL_DIR}/mnt/tmp" || die "bind mount failed"
+mount -t proc none "${INSTALL_DIR}/proc" || die "mounting proc failed"
+mount -t sysfs none "${INSTALL_DIR}/sys" || die "mounting sys failed"
+
+echo "$0: starting chroot."
+echo "cd /mnt/tmp before building"
+echo
+chroot ${INSTALL_DIR} env HOME=/mnt/tmp /bin/bash
+
+echo "$0: exiting chroot."
+
+exit 0