Initial cut of a script that installs chroot environment. This can for...

build/install-chroot.sh

+#!/bin/bash -e
+
+# Copyright (c) 2010 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# This script installs Debian-derived distributions in a chroot environment.
+# It can for example be used to have an accurate 32bit build and test
+# environment when otherwise working on a 64bit machine.
+# N. B. it is unlikely that this script will ever work on anything other than a
+# Debian-derived system.
+
+# Check that we are running as a regular user
+[ "$(id -nu)" = root ] && {
+  echo "Run this script as a regular user and provide your \"sudo\""           \
+       "password if requested" >&2
+  exit 1
+}
+mkdir -p "$HOME/chroot/"
+
+# Error handler
+trap 'exit 1' INT TERM QUIT
+trap 'sudo apt-get clean; tput bel; echo; echo Failed' EXIT
+
+# Install any missing applications that this script relies on. If these packages
+# are already installed, don't force another "apt-get install". That would
+# prevent them from being auto-removed, if they ever become eligible for that.
+# And as this script only needs the packages once, there is no good reason to
+# introduce a hard dependency on things such as dchroot and debootstrap.
+dep=
+for i in dchroot debootstrap; do
+  [ -d /usr/share/doc/"$i" ] || dep="$dep $i"
+done
+[ -n "$dep" ] && sudo apt-get -y install $dep
+sudo apt-get -y install schroot
+
+# Create directory for chroot
+sudo mkdir -p /var/lib/chroot
+
+# Find chroot environments that can be installed with debootstrap
+targets="$(cd /usr/share/debootstrap/scripts
+           ls | grep '^[a-z]*$')"
+
+# Ask user to pick one of the available targets
+echo "The following targets are available to be installed in a chroot:"
+j=1; for i in $targets; do
+  printf '%4d: %s\n' "$j" "$i"
+  j=$(($j+1))
+done
+while :; do
+  printf "Which target would you like to install: "
+  read n
+  [ "$n" -gt 0 -a "$n" -lt "$j" ] >&/dev/null && break
+done
+j=1; for i in $targets; do
+  [ "$j" -eq "$n" ] && { distname="$i"; break; }
+  j=$(($j+1))
+done
+
+# On x86-64, ask whether the user wants to install x86-32 or x86-64
+archflag=
+arch=
+if [ "$(uname -m)" = x86_64 ]; then
+  while :; do
+    echo "You are running a 64bit kernel. This allows you to install either a"
+    printf "32bit or a 64bit chroot environment. %s"                           \
+           "Which one do you want (32, 64) "
+    read arch
+    [ "${arch}" == 32 -o "${arch}" == 64 ] && break
+  done
+  [ "${arch}" == 32 ] && archflag="--arch i386" || archflag="--arch amd64"
+  arch="${arch}bit"
+fi
+target="${distname}${arch}"
+
+# Don't overwrite an existing installation
+[ -d /var/lib/chroot/"${target}" ] && {
+  echo "This chroot already exists on your machine." >&2
+  echo "Delete /var/lib/chroot/${target} if you want to start over." >&2
+  exit 1
+}
+sudo mkdir -p /var/lib/chroot/"${target}"
+
+# Remove stale entry from /etc/schroot/schroot.conf. Entries start
+# with the target name in square brackets, followed by an arbitrary
+# number of lines. The entry stops when either the end of file has
+# been reached, or when the beginning of a new target is encountered.
+# This means, we cannot easily match for a range of lines in
+# "sed". Instead, we actually have to iterate over each line and check
+# whether it is the beginning of a new entry.
+sudo sed -ni '/^[[]'"${target%bit}"']$/,${:1;n;/^[[]/b2;b1;:2;p;n;b2};p'       \
+         /etc/schroot/schroot.conf
+
+# Download base system. This takes some time
+grep ubuntu.com /usr/share/debootstrap/scripts/"${distname}" >&/dev/null &&
+ mirror="http://archive.ubuntu.com/ubuntu" ||
+ mirror="http://ftp.us.debian.org/debian"
+ sudo debootstrap ${archflag} "${distname}" /var/lib/chroot/"${target}"        \
+                  "$mirror"
+
+# Add new entry to /etc/schroot/schroot.conf
+grep ubuntu.com /usr/share/debootstrap/scripts/"${distname}" >&/dev/null &&
+  brand="Ubuntu" || brand="Debian"
+sudo sh -c 'cat >>/etc/schroot/schroot.conf' <<EOF
+[${target%bit}]
+description=${brand} ${distname} ${arch}
+type=directory
+directory=/var/lib/chroot/${target}
+priority=3
+users=root
+groups=admin
+root-groups=admin
+personality=linux$([ "${arch}" != 64bit ] && echo 32)
+script-config=script-${target}
+
+EOF
+
+# Set up a special directory that changes contents depending on the target
+# that is executing.
+sed '/^FSTAB=/s,/mount-defaults",/mount-'"${target}"'",'                       \
+         /etc/schroot/script-defaults |
+  sudo sh -c 'cat >/etc/schroot/script-'"${target}"
+sudo cp /etc/schroot/mount-defaults /etc/schroot/mount-"${target}"
+echo "$HOME/chroot/.${target} $HOME/chroot none rw,bind 0 0" |
+  sudo sh -c 'cat >>/etc/schroot/mount-'"${target}"
+mkdir -p "$HOME/chroot/.${target}"
+
+# Install a helper script to launch commands in the chroot
+sudo sh -c 'cat >/usr/local/bin/'"${target%bit}" <<EOF
+#!/bin/bash
+if [ \$# -eq 0 ]; then
+  exec schroot -c ${target%bit} -p
+else
+  p="\$1"; shift
+  exec schroot -c ${target%bit} -p "\$p" -- "\$@"
+fi
+exit 1
+EOF
+sudo chown root:root /usr/local/bin/"${target%bit}"
+sudo chmod 755 /usr/local/bin/"${target%bit}"
+
+# Add a few more repositories to the chroot
+[ -r /var/lib/chroot/${target}/etc/apt/sources.list ] &&
+sudo sed -i 's/ main$/ main restricted universe multiverse/
+             p
+             t1
+             d
+          :1;s/^deb/deb-src/
+             t
+             d' /var/lib/chroot/${target}/etc/apt/sources.list
+
+# Update packages
+sudo schroot -c "${target%bit}" -p -- /bin/sh -c '
+  apt-get update; apt-get -y dist-upgrade' || :
+
+# Install a couple of missing packages
+for i in debian-keyring ubuntu-keyring locales sudo; do
+  [ -d "/var/lib/chroot/${target}/usr/share/doc/$i" ] ||
+    sudo schroot -c "${target%bit}" -p -- apt-get -y install "$i" || :
+done
+
+# Configure locales
+sudo schroot -c "${target%bit}" -p -- /bin/sh -c '
+  l='"${LANG:-en_US}"'; l="${l%%.*}"
+  [ -r /etc/locale.gen ] &&
+    sed -i "s/^# \($l\)/\1/" /etc/locale.gen
+  locale-gen $LANG en_US en_US.UTF-8' || :
+
+# Configure "sudo" package
+sudo schroot -c "${target%bit}" -p -- /bin/sh -c '
+  egrep '"'^$(id -nu) '"' /etc/sudoers >/dev/null 2>&1 ||
+  echo '"'$(id -nu) ALL=(ALL) ALL'"' >>/etc/sudoers'
+
+# Install a few more commonly used packages
+sudo schroot -c "${target%bit}" -p -- apt-get -y install                       \
+  autoconf automake1.9 dpkg-dev g++-multilib gcc-multilib gdb less libtool     \
+  strace
+
+# If running a 32bit environment on a 64bit machine, install a few binaries
+# as 64bit.
+if [ "${arch}" = 32bit ] && file /bin/bash 2>/dev/null | grep -q x86-64; then
+  sudo schroot -c "${target%bit}" -p -- apt-get -y install                     \
+    lib64expat1 lib64ncurses5 lib64readline6 lib64z1
+  dep=
+  for i in binutils gdb strace; do
+    [ -d /usr/share/doc/"$i" ] || dep="$dep $i"
+  done
+  [ -n "$dep" ] && sudo apt-get -y install $dep
+  sudo cp /usr/bin/gdb /var/lib/chroot/${target}/usr/local/bin/
+  sudo cp /usr/bin/ld /var/lib/chroot/${target}/usr/local/bin/
+  for i in libbfd libpython; do
+    lib="$({ ldd /usr/bin/ld; ldd /usr/bin/gdb; } |
+           grep "$i" | awk '{ print $3 }')"
+    if [ -n "$lib" -a -r "$lib" ]; then
+      sudo cp "$lib" /var/lib/chroot/${target}/usr/lib64/
+    fi
+  done
+  for lib in libssl libcrypt; do
+    sudo cp /usr/lib/$lib* /var/lib/chroot/${target}/usr/lib64/ || :
+  done
+fi
+
+# Clean up package files
+sudo schroot -c "${target%bit}" -p -- apt-get clean
+sudo apt-get clean
+
+# Let the user know what we did
+trap '' INT TERM QUIT
+trap '' EXIT
+cat <<EOF
+
+
+Successfully installed ${distname} ${arch}
+
+You can run programs inside of the chroot by invoking the "${target%bit}"
+command.
+
+Your home directory is shared between the host and the chroot. But I configured
+$HOME/chroot to be private to the chroot environment. You can use it
+for files that need to differ between environments.
+EOF