crosutils: move enter_chroot.sh to sdk_lib, code unchanged

* Removed boilerplate, simplified search code.
* Fixed one too long line

This will unfortunately kill all outstanding CLs into enter_chroot.

BUG=chromium-os:18750
TEST=run it

Change-Id: I39c45fa8163d92487b512e7e8d298ce9231f4bd2
Reviewed-on: http://gerrit.chromium.org/gerrit/5830
Tested-by: Zdenek Behan <zbehan@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
Reviewed-by: Anush Elangovan <anush@chromium.org>
Reviewed-by: Richard Barnette <jrbarnette@chromium.org>
Reviewed-by: David James <davidjames@chromium.org>
diff --git a/sdk_lib/enter_chroot.sh b/sdk_lib/enter_chroot.sh
new file mode 100755
index 0000000..0827432
--- /dev/null
+++ b/sdk_lib/enter_chroot.sh
@@ -0,0 +1,443 @@
+#!/bin/bash
+
+# Copyright (c) 2011 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
+
+# The script lives in scripts/ or scripts/sdk_lib/
+for path in "$(dirname $0)" "$(dirname $0)/../"; do
+  if [ -r "${path}/common.sh" ]; then
+    SCRIPT_ROOT=${path}
+    break
+  fi
+done
+
+. "${SCRIPT_ROOT}/common.sh" || { echo "Unable to load common.sh"; exit 1; }
+
+# Script must be run outside the chroot and as a regular user.
+assert_outside_chroot
+assert_not_root_user
+
+# 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_string build_number "" \
+  "The build-bot build number (when called by buildbot only)." "b"
+DEFINE_string chrome_root "" \
+  "The root of your chrome browser source. Should contain a 'src' subdir."
+DEFINE_string chrome_root_mount "/home/$USER/chrome_root" \
+  "The mount point of the chrome broswer source in the chroot."
+
+DEFINE_boolean official_build $FLAGS_FALSE \
+  "Set CHROMEOS_OFFICIAL=1 for release builds."
+DEFINE_boolean mount $FLAGS_FALSE "Only set up mounts."
+DEFINE_boolean unmount $FLAGS_FALSE "Only tear down mounts."
+DEFINE_boolean ssh_agent $FLAGS_TRUE "Import ssh agent."
+DEFINE_boolean verbose $FLAGS_FALSE "Print out actions taken"
+
+# More useful help
+FLAGS_HELP="USAGE: $0 [flags] [VAR=value] [-- command [arg1] [arg2] ...]
+
+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 neither
+the command nor args should include single quotes.  For example:
+
+    $0 -- ./build_platform_packages.sh
+
+Otherwise, provides an interactive shell.
+"
+
+# Version of info from common.sh that only echos if --verbose is set.
+function debug {
+  if [ $FLAGS_verbose -eq $FLAGS_TRUE ]; then
+    info "$*"
+  fi
+}
+
+# Parse command line flags
+FLAGS "$@" || exit 1
+eval set -- "${FLAGS_ARGV}"
+
+if [ $FLAGS_official_build -eq $FLAGS_TRUE ]; then
+   CHROMEOS_OFFICIAL=1
+fi
+
+# Only now can we die on error.  shflags functions leak non-zero error codes,
+# so will die prematurely if 'set -e' is specified before now.
+# TODO: replace shflags with something less error-prone, or contribute a fix.
+set -e
+
+INNER_CHROME_ROOT=$FLAGS_chrome_root_mount  # inside chroot
+CHROME_ROOT_CONFIG="/var/cache/chrome_root"  # inside chroot
+INNER_DEPOT_TOOLS_ROOT="/home/$USER/depot_tools"  # inside chroot
+FUSE_DEVICE="/dev/fuse"
+AUTOMOUNT_PREF="/apps/nautilus/preferences/media_automount"
+SAVED_AUTOMOUNT_PREF_FILE="/tmp/.automount_pref"
+
+sudo chmod 0777 "$FLAGS_chroot/var/lock"
+
+LOCKFILE="$FLAGS_chroot/var/lock/enter_chroot"
+SYNCERPIDFILE="${FLAGS_chroot}/var/tmp/enter_chroot_sync.pid"
+
+
+function ensure_mounted {
+  # If necessary, mount $source in the host FS at $target inside the
+  # chroot directory with $mount_args.
+  local source="$1"
+  local mount_args="$2"
+  local target="$3"
+
+  local mounted_path="$(readlink -f "${FLAGS_chroot}/$target")"
+
+  if [ -z "$(mount | grep -F "on ${mounted_path} ")" ]; then
+    # Attempt to make the mountpoint as the user.  This depends on the
+    # fact that all mountpoints that should be owned by root are
+    # already present.
+    mkdir -p "${mounted_path}"
+
+    # NB:  mount_args deliberately left unquoted
+    debug mount ${mount_args} "${source}" "${mounted_path}"
+    sudo -- mount ${mount_args} "${source}" "${mounted_path}" || \
+      die "Could not mount ${source} on ${mounted_path}"
+  fi
+}
+
+function env_sync_proc {
+  # This function runs and performs periodic updates to the chroot env, if
+  # necessary.
+
+  local poll_interval=10
+  local sync_files="etc/resolv.conf etc/hosts"
+
+  # Make sure the synced files are writable by normal user, so that we
+  # don't have to sudo inside the loop.
+  for file in ${sync_files}; do
+    sudo chown ${USER} ${FLAGS_chroot}/${file} 1>&2
+  done
+
+  # Drop stdin, stderr, stdout, and chroot lock.
+  # This is needed for properly daemonizing the process.
+  exec 0>&- 1>&- 2>&- 200>&-
+
+  while true; do
+    # Sync files
+    for file in ${sync_files}; do
+      if ! cmp /${file} ${FLAGS_chroot}/${file} &> /dev/null; then
+        cp -f /${file} ${FLAGS_chroot}/${file}
+      fi
+    done
+
+    sleep ${poll_interval}
+  done
+}
+
+function copy_ssh_config {
+  # Copy user .ssh/config into the chroot filtering out strings not supported
+  # by the chroot ssh. The chroot .ssh directory is passed in as the first
+  # parameter.
+
+  # ssh options to filter out. The entire strings containing these substrings
+  # will be deleted before copying.
+  local bad_options=(
+    'UseProxyIf='
+    'GSSAPIAuthentication no'
+  )
+  local sshc="${HOME}/.ssh/config"
+  local chroot_ssh_dir="${1}"
+  local filter
+  local option
+
+  if [ ! -f "${sshc}" ]; then
+    return # Nothing to copy.
+  fi
+
+  for option in "${bad_options[@]}"
+  do
+    if [ -z "${filter}" ]; then
+      filter="${option}"
+    else
+      filter+="\\|${option}"
+    fi
+  done
+
+  sed "/^.*\(${filter}\).*$/d" "${sshc}" > "${chroot_ssh_dir}/config"
+}
+
+function setup_env {
+  # Validate sudo timestamp before entering the critical section so that we
+  # don't stall for a password while we have the lockfile.
+  # Don't use sudo -v since that has issues on machines w/ no password.
+  sudo echo "" > /dev/null
+
+  (
+    flock 200
+    echo $$ >> "$LOCKFILE"
+
+    # If there isn't a syncer daemon started already, start one.  The
+    # daemon is considered to not be started under the following
+    # conditions:
+    #
+    #   o There is no PID file
+    #
+    #   o The PID file is 0 bytes in size, which might be a partial
+    #     manifestation of chromium-os:17680.  This situation will not
+    #     occur anymore, but you might have a chroot which was already
+    #     affected.
+    #
+    #   o The /proc node for the process named by the PID file does
+    #     not exist.
+    #
+    #     Note: This does not address PID recycling.  While
+    #           increasingly unlikely, it is possible for the PID in
+    #           the PID file to refer to a running process that is not
+    #           the syncer process.  Since the PID file is now
+    #           removed, I think it is only possible for this to occur
+    #           if your system crashes and the PID file exists after
+    #           restart.
+    #
+    # The daemon is killed by the enter_chroot that exits last.
+    if [ -f "${SYNCERPIDFILE}" ] && [ ! -s "${SYNCERPIDFILE}" ] ; then
+        info "You may have suffered from chromium-os:17680 and";
+        info "could have stray 'enter_chroot.sh' processes running.";
+        info "You must manually kill any such stray processes.";
+        info "Exit all chroot shells; remaining 'enter_chroot.sh'";
+        info "processes are probably stray.";
+        sudo rm -f "${SYNCERPIDFILE}";
+    fi;
+    if ! [ -f "${SYNCERPIDFILE}" ] || \
+       ! [ -d /proc/$(cat "${SYNCERPIDFILE}") ]; then
+      debug "Starting sync process"
+      env_sync_proc &
+      echo $! > "${SYNCERPIDFILE}"
+      disown $!
+    fi
+
+    debug "Mounting chroot environment."
+    ensure_mounted none "-t proc" /proc
+    ensure_mounted none "-t sysfs" /sys
+    ensure_mounted /dev "--bind" /dev
+    ensure_mounted none "-t devpts" /dev/pts
+    ensure_mounted "${FLAGS_trunk}" "--bind" "${CHROOT_TRUNK_DIR}"
+
+    if [ $FLAGS_ssh_agent -eq $FLAGS_TRUE ]; then
+      TARGET_DIR="$(readlink -f "${FLAGS_chroot}/home/${USER}/.ssh")"
+      if [ -n "${SSH_AUTH_SOCK}" -a -d "${HOME}/.ssh" ]; then
+        mkdir -p "${TARGET_DIR}"
+        cp -r "${HOME}/.ssh/known_hosts" "${TARGET_DIR}"
+        cp -r ${HOME}/.ssh/*.pub "${TARGET_DIR}"
+        copy_ssh_config "${TARGET_DIR}"
+        ASOCK="$(dirname "${SSH_AUTH_SOCK}")"
+        ensure_mounted "${ASOCK}" "--bind" "${ASOCK}"
+      fi
+    fi
+
+    MOUNTED_PATH="$(readlink -f "${FLAGS_chroot}${INNER_CHROME_ROOT}")"
+    if [ -z "$(mount | grep -F "on $MOUNTED_PATH ")" ]; then
+      ! CHROME_ROOT="$(readlink -f "$FLAGS_chrome_root")"
+      if [ -z "$CHROME_ROOT" ]; then
+        ! CHROME_ROOT="$(cat "${FLAGS_chroot}${CHROME_ROOT_CONFIG}" \
+          2>/dev/null)"
+        CHROME_ROOT_AUTO=1
+      fi
+      if [[ ( -n "$CHROME_ROOT" ) ]]; then
+        if [[ ( ! -d "${CHROME_ROOT}/src" ) ]]; then
+          error "Not mounting chrome source"
+          sudo rm -f "${FLAGS_chroot}${CHROME_ROOT_CONFIG}"
+          if [[ ! "$CHROME_ROOT_AUTO" ]]; then
+            exit 1
+          fi
+        else
+          debug "Mounting chrome source at: $INNER_CHROME_ROOT"
+          sudo bash -c "echo '$CHROME_ROOT' > \
+            '${FLAGS_chroot}${CHROME_ROOT_CONFIG}'"
+          mkdir -p "$MOUNTED_PATH"
+          sudo mount --bind "$CHROME_ROOT" "$MOUNTED_PATH" || \
+            die "Could not mount $MOUNTED_PATH"
+        fi
+      fi
+    fi
+
+    MOUNTED_PATH="$(readlink -f "${FLAGS_chroot}${INNER_DEPOT_TOOLS_ROOT}")"
+    if [ -z "$(mount | grep -F "on $MOUNTED_PATH ")" ]; then
+      if [ $(which gclient 2>/dev/null) ]; then
+        debug "Mounting depot_tools"
+        DEPOT_TOOLS=$(dirname "$(which gclient)")
+        mkdir -p "$MOUNTED_PATH"
+        if ! sudo mount --bind "$DEPOT_TOOLS" "$MOUNTED_PATH"; then
+          warn "depot_tools failed to mount; perhaps it's on NFS?"
+          warn "This may impact chromium build."
+        fi
+      fi
+    fi
+
+    # Install fuse module.
+    if [ -c "${FUSE_DEVICE}" ]; then
+      sudo modprobe fuse 2> /dev/null ||\
+        warn "-- Note: modprobe fuse failed.  gmergefs will not work"
+    fi
+
+    # Turn off automounting of external media when we enter the
+    # chroot; thus we don't have to worry about being able to unmount
+    # from inside.
+    if [ $(which gconftool-2 2>/dev/null) ]; then
+      gconftool-2 -g ${AUTOMOUNT_PREF} > \
+        "${FLAGS_chroot}${SAVED_AUTOMOUNT_PREF_FILE}"
+      if [ $(gconftool-2 -s --type=boolean ${AUTOMOUNT_PREF} false) ]; then
+        warn "-- Note: USB sticks may be automounted by your host OS."
+        warn "-- Note: If you plan to burn bootable media, you may need to"
+        warn "-- Note: unmount these devices manually, or run image_to_usb.sh"
+        warn "-- Note: outside the chroot."
+      fi
+    fi
+
+    if [ -d "$HOME/.subversion" ]; then
+      TARGET="/home/${USER}/.subversion"
+      mkdir -p "${FLAGS_chroot}${TARGET}"
+      ensure_mounted "${HOME}/.subversion" "--bind" "${TARGET}"
+    fi
+
+    # Configure committer username and email in chroot .gitconfig
+    git config -f ${FLAGS_chroot}/home/${USER}/.gitconfig --replace-all \
+      user.name "$(cd /tmp; git var GIT_COMMITTER_IDENT | \
+      sed -e 's/ *<.*//')" || true
+    git config -f ${FLAGS_chroot}/home/${USER}/.gitconfig --replace-all \
+      user.email "$(cd /tmp; git var GIT_COMMITTER_IDENT | \
+        sed -e 's/.*<\([^>]*\)>.*/\1/')" || true
+
+    # Fix permissions on shared memory to allow non-root users access to POSIX
+    # semaphores.
+    sudo chmod -R 777 "${FLAGS_chroot}/dev/shm"
+  ) 200>>"$LOCKFILE" || die "setup_env failed"
+}
+
+function teardown_env {
+  # Validate sudo timestamp before entering the critical section so that we
+  # don't stall for a password while we have the lockfile.
+  # Don't use sudo -v since that has issues on machines w/ no password.
+  sudo echo "" > /dev/null
+
+  # Only teardown if we're the last enter_chroot to die
+  (
+    flock 200
+
+    # check each pid in $LOCKFILE to see if it's died unexpectedly
+    TMP_LOCKFILE="$LOCKFILE.tmp"
+
+    echo -n > "$TMP_LOCKFILE"  # Erase/reset temp file
+    cat "$LOCKFILE" | while read PID; do
+      if [ "$PID" = "$$" ]; then
+        # ourself, leave PROC_NAME empty
+        PROC_NAME=""
+      else
+        PROC_NAME=$(ps --pid $PID -o comm=)
+      fi
+
+      if [ ! -z "$PROC_NAME" ]; then
+        # All good, keep going
+        echo "$PID" >> "$TMP_LOCKFILE"
+      fi
+    done
+    # Remove any dups from lock file while installing new one
+    sort -n "$TMP_LOCKFILE" | uniq > "$LOCKFILE"
+
+    if [ $(which gconftool-2 2>/dev/null) ]; then
+      SAVED_PREF=$(cat "${FLAGS_chroot}${SAVED_AUTOMOUNT_PREF_FILE}")
+      gconftool-2 -s --type=boolean ${AUTOMOUNT_PREF} ${SAVED_PREF} || \
+        warn "could not re-set your automount preference."
+    fi
+
+    if [ -s "$LOCKFILE" ]; then
+      debug "At least one other pid is running in the chroot, so not"
+      debug "tearing down env."
+    else
+      debug "Stopping syncer process"
+      # If another process entering the chroot is blocked on this
+      # flock in setup_env(), it can be a race condition.
+      #
+      # When this locked region is exited, the setup_env() flock can
+      # be entered before the script can exit and the /proc entry for
+      # the PID is removed.  The newly-created chroot will not end up
+      # with a syncer process.  To avoid that situation, remove the
+      # syncer PID file.
+      #
+      # The syncer PID file should also be removed because the kernel
+      # will reuse PIDs.  It's possible that the PID in the syncer PID
+      # has been reused by another process; make sure we don't skip
+      # starting the syncer process when this occurs by deleting the
+      # PID file.
+      kill $(cat "${SYNCERPIDFILE}") && \
+          sudo rm -f "${SYNCERPIDFILE}" || \
+          debug "Unable to clean up syncer process.";
+
+      MOUNTED_PATH=$(readlink -f "$FLAGS_chroot")
+      debug "Unmounting chroot environment."
+      # sort the list of mounts in reverse order, to ensure umount of
+      # cascading mounts in proper order
+      for i in \
+        $(mount | grep -F "on $MOUNTED_PATH/" | sort -r | awk '{print $3}'); do
+        safe_umount "$i"
+      done
+    fi
+  ) 200>>"$LOCKFILE" || die "teardown_env failed"
+}
+
+if [ $FLAGS_mount -eq $FLAGS_TRUE ]; then
+  setup_env
+  info "Make sure you run"
+  info "    $0 --unmount"
+  info "before deleting $FLAGS_chroot"
+  info "or you'll end up deleting $FLAGS_trunk too!"
+  exit 0
+fi
+
+if [ $FLAGS_unmount -eq $FLAGS_TRUE ]; then
+  teardown_env
+  exit 0
+fi
+
+# Make sure we unmount before exiting
+trap teardown_env EXIT
+setup_env
+
+CHROOT_PASSTHRU="BUILDBOT_BUILD=$FLAGS_build_number \
+CHROMEOS_OFFICIAL=$CHROMEOS_OFFICIAL"
+CHROOT_PASSTHRU="${CHROOT_PASSTHRU} \
+CHROMEOS_RELEASE_APPID=${CHROMEOS_RELEASE_APPID:-"{DEV-BUILD}"}"
+
+# Set CHROMEOS_VERSION_TRACK, CHROMEOS_VERSION_AUSERVER,
+# CHROMEOS_VERSION_DEVSERVER as environment variables to override the default
+# assumptions (local AU server). These are used in cros_set_lsb_release, and
+# are used by external Chromium OS builders.
+CHROOT_PASSTHRU="${CHROOT_PASSTHRU} \
+CHROMEOS_VERSION_TRACK=${CHROMEOS_VERSION_TRACK} \
+CHROMEOS_VERSION_AUSERVER=${CHROMEOS_VERSION_AUSERVER} \
+CHROMEOS_VERSION_DEVSERVER=${CHROMEOS_VERSION_DEVSERVER}"
+
+# Pass proxy variables into the environment.
+for type in http_proxy ftp_proxy all_proxy GIT_PROXY_COMMAND GIT_SSH; do
+   eval value=\$${type}
+   if [ -n "${value}" ]; then
+      CHROOT_PASSTHRU="${CHROOT_PASSTHRU} ${type}=${value}"
+   fi
+done
+
+# Run command or interactive shell.  Also include the non-chrooted path to
+# the source trunk for scripts that may need to print it (e.g.
+# build_image.sh).
+sudo -- chroot "$FLAGS_chroot" sudo -i -u $USER $CHROOT_PASSTHRU \
+  EXTERNAL_TRUNK_PATH="${FLAGS_trunk}" SSH_AGENT_PID="${SSH_AGENT_PID}" \
+  SSH_AUTH_SOCK="${SSH_AUTH_SOCK}" "$@"
+
+# Remove trap and explicitly unmount
+trap - EXIT
+teardown_env