flatcar-scripts/enter_chroot.sh
rspangler@google.com d74220d772 Start copying over source.
git-svn-id: svn://chrome-svn/chromeos/trunk@4 06c00378-0e64-4dae-be16-12b19f9950a1
2009-10-09 20:56:14 +00:00

127 lines
3.8 KiB
Bash
Executable File

#!/bin/bash
# Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
# Script to enter the chroot environment
# Load common constants. This should be the first executable line.
# The path to common.sh should be relative to your script's location.
. "$(dirname "$0")/common.sh"
# Script must be run outside the chroot
assert_outside_chroot
# Define command line flags
# See http://code.google.com/p/shflags/wiki/Documentation10x
DEFINE_string chroot "$DEFAULT_CHROOT_DIR" \
"The destination dir for the chroot environment." "d"
DEFINE_string trunk "$GCLIENT_ROOT" \
"The source trunk to bind mount within the chroot." "s"
DEFINE_boolean mount $FLAGS_FALSE "Only set up mounts."
DEFINE_boolean unmount $FLAGS_FALSE "Only tear down mounts."
DEFINE_boolean svn_rev $FLAGS_FALSE "Pass subversion revision into chroot."
# More useful help
FLAGS_HELP="USAGE: $0 [flags] [VAR=value] [-- \"command\"]
One or more VAR=value pairs can be specified to export variables into
the chroot environment. For example:
$0 FOO=bar BAZ=bel
If [-- \"command\"] is present, runs the command inside the chroot,
after changing directory to /$USER/trunk/src/scripts. Note that the
command should be enclosed in quotes to prevent interpretation by the
shell before getting into the chroot. For example:
$0 -- \"./build_platform_packages.sh\"
Otherwise, provides an interactive shell.
"
# Parse command line flags
FLAGS "$@" || exit 1
eval set -- "${FLAGS_ARGV}"
# Only now can we die on error. shflags functions leak non-zero error codes,
# so will die prematurely if 'set -e' is specified before now.
# TODO: replace shflags with something less error-prone, or contribute a fix.
set -e
function setup_env {
echo "Mounting chroot environment."
# Mount only if not already mounted
MOUNTED_PATH="$(readlink -f "$FLAGS_chroot/proc")"
if [ -z "$(mount | grep -F "on $MOUNTED_PATH")" ]
then
sudo mount none -t proc "$MOUNTED_PATH"
fi
MOUNTED_PATH="$(readlink -f "$FLAGS_chroot/dev/pts")"
if [ -z "$(mount | grep -F "on $MOUNTED_PATH")" ]
then
sudo mount none -t devpts "$MOUNTED_PATH"
fi
MOUNTED_PATH="$(readlink -f "${FLAGS_chroot}$CHROOT_TRUNK_DIR")"
if [ -z "$(mount | grep -F "on $MOUNTED_PATH")" ]
then
sudo mount --bind "$FLAGS_trunk" "$MOUNTED_PATH"
fi
}
function teardown_env {
echo "Unmounting chroot environment."
mount | grep "on $(readlink -f "$FLAGS_chroot")" | awk '{print $3}' \
| xargs -r -L1 sudo umount
}
if [ $FLAGS_mount -eq $FLAGS_TRUE ]
then
setup_env
echo "Make sure you run"
echo " $0 --unmount"
echo "before deleting $FLAGS_chroot"
echo "or you'll end up deleting $FLAGS_trunk too!"
exit 0
fi
if [ $FLAGS_unmount -eq $FLAGS_TRUE ]
then
teardown_env
exit 0
fi
# Make sure we unmount before exiting
trap teardown_env EXIT
setup_env
if [ $FLAGS_svn_rev -eq $FLAGS_TRUE ]
then
# Get the subversion revision to pass into the chroot.
#
# This must be determined outside the chroot because (1) there is no
# svn inside the chroot, and (2) if there were it would likely be
# the wrong version, which would mess up the .svn directories.
#
# Note that this fixes $CHROMEOS_REVISION at the time the chroot is
# entered. That's ok for the main use case of automated builds,
# which pass each command line into a separate call to enter_chroot
# so always have up-to-date info. For developer builds, there isn't
# really a single revision anyway, since the developer may have
# hand-sync'd some subdirs and edited files in others.
SVNREV="CHROMEOS_REVISION=$(svn info | grep "Revision: " | awk '{print $2}')"
fi
# Run command or interactive shell
sudo chroot "$FLAGS_chroot" sudo -i -u $USER $SVNREV "$@"
# Remove trap and explicitly unmount
trap - EXIT
teardown_env