sdk_lib/*: Make --cache_dir option required.

This is forced by cros_sdk; in conjunction w/ this,
drop --distfiles and mangle the chroot on during entrance
dropping a symlink in the old /var/cache/distfiles location
pointing to the new mounted cache_dir location.

Additionally, thread CHROMEOS_CACHEDIR down through the end.
Do this without relying on a version upgrade script- we can't
require they be run before entering, thus we exploit the fact
that cros_sdk explicitly forces a write lock to do the upgrade,
if we see the old form we know we can do the upgrade w/out
worrying about collisions.

CQ-DEPEND=CL:33871

BUG=chromium-os:34457
TEST=manual testing.

Change-Id: I6805266e3ec683f05d3ba615f9e8840642a28e48
Reviewed-on: https://gerrit.chromium.org/gerrit/33868
Commit-Ready: Brian Harring <ferringb@chromium.org>
Reviewed-by: Brian Harring <ferringb@chromium.org>
Tested-by: Brian Harring <ferringb@chromium.org>

sdk_lib/enter_chroot.sh

@@ -27,8 +27,7 @@ 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_string distfiles "" \
+DEFINE_string cache_dir "" "Directory to use for caching."
-  "Override the destination dir used for distfiles."
 
 DEFINE_boolean official_build $FLAGS_FALSE \
   "Set CHROMEOS_OFFICIAL=1 for release builds."
@@ -73,8 +72,8 @@ if [ $FLAGS_official_build -eq $FLAGS_TRUE ]; then
    CHROMEOS_OFFICIAL=1
 fi
 
-[ -z "${FLAGS_distfiles}" ] && \
+[ -z "${FLAGS_cache_dir}" ] && \
-  FLAGS_distfiles="${FLAGS_trunk}/distfiles"
+  die "--cache_dir is required"
 
 # Only now can we die on error.  shflags functions leak non-zero error codes,
 # so will die prematurely if 'switch_to_strict_mode' is specified before now.
@@ -359,10 +358,25 @@ setup_env() {
     fi
     unset REFERENCE_DIR
 
-    debug "Setting up shared distfiles directory."
+    chroot_cache='/var/cache/chromeos-cache'
-    mkdir -p "${FLAGS_distfiles}"/{target,host}
+    debug "Setting up shared cache dir directory."
-    sudo mkdir -p "${FLAGS_chroot}/var/cache/distfiles/"
+    mkdir -p "${FLAGS_cache_dir}"/distfiles/{target,host}
-    queue_mount "${FLAGS_distfiles}" "--bind" "/var/cache/distfiles"
+    sudo mkdir -p "${FLAGS_chroot}/${chroot_cache}"
+    queue_mount "${FLAGS_cache_dir}" "--bind" "${chroot_cache}"
+    # TODO(build): remove this as of 12/01/12.
+    # Because of how distfiles -> cache_dir was deployed, if this isn't
+    # a symlink, we *know* the ondisk pathways aren't compatible- thus
+    # fix it now.
+    distfiles_path="${FLAGS_chroot}/var/cache/distfiles"
+    if [ ! -L "${distfiles_path}" ]; then
+      # While we're at it, ensure the var is exported w/in the chroot; it
+      # won't exist if distfiles isn't a symlink.
+      p="${FLAGS_chroot}/etc/profile.d/chromeos-cache.sh"
+      sudo_multi "rm -rf '${distfiles_path}'" \
+                 "ln -s chromeos-cache/distfiles '${distfiles_path}'" \
+                 "echo 'export CHROMEOS_CACHEDIR=${chroot_cache}' > '${p}'" \
+                 "chmod 0644 '${p}'"
+    fi
 
     if [ $FLAGS_ssh_agent -eq $FLAGS_TRUE ]; then
       if [ -n "${SSH_AUTH_SOCK}" -a -d "${HOME}/.ssh" ]; then

sdk_lib/make_chroot.sh

@@ -45,6 +45,7 @@ DEFINE_string stage3_date "2010.03.09" \
   "Use the stage3 with the given date."
 DEFINE_string stage3_path "" \
   "Use the stage3 located on this path."
+DEFINE_string cache_dir "" "Directory to store caches within."
 
 # Parse command line flags.
 FLAGS_HELP="usage: $SCRIPT_NAME [flags]"
@@ -63,6 +64,10 @@ umask 022
 # TODO: replace shflags with something less error-prone, or contribute a fix.
 switch_to_strict_mode
 
+[[ "${FLAGS_delete}" == "${FLAGS_FALSE}" ]] && \
+  [[ -z "${FLAGS_cache_dir}" ]] && \
+  die "--cache_dir is required"
+
 . "${SCRIPT_ROOT}"/sdk_lib/make_conf_util.sh
 
 FULLNAME="ChromeOS Developer"
@@ -93,7 +98,8 @@ ENTER_CHROOT_ARGS=(
 
 # Invoke enter_chroot.  This can only be used after sudo has been installed.
 enter_chroot() {
-  "$ENTER_CHROOT" --chroot "$FLAGS_chroot" -- "${ENTER_CHROOT_ARGS[@]}" "$@"
+  "$ENTER_CHROOT" --cache_dir "${FLAGS_cache_dir}" --chroot "$FLAGS_chroot" \
+    -- "${ENTER_CHROOT_ARGS[@]}" "$@"
 }
 
 # Invoke enter_chroot running the command as root, and w/out sudo.
@@ -101,6 +107,7 @@ enter_chroot() {
 early_env=()
 early_enter_chroot() {
   "$ENTER_CHROOT" --chroot "$FLAGS_chroot" --early_make_chroot \
+    --cache_dir "${FLAGS_cache_dir}" \
     -- "${ENTER_CHROOT_ARGS[@]}" "${early_env[@]}" "$@"
 }
 
@@ -208,8 +215,15 @@ init_setup () {
 
    # Create directories referred to by our conf files.
    sudo mkdir -p -m 775 "${FLAGS_chroot}/var/lib/portage/pkgs" \
-     "${FLAGS_chroot}/var/cache/distfiles" \
+     "${FLAGS_chroot}/var/cache/"chromeos-{cache,chrome} \
-     "${FLAGS_chroot}/var/cache/chromeos-chrome"
+     "${FLAGS_chroot}/etc/profile.d"
+
+   echo "export CHROMEOS_CACHEDIR=/var/cache/chromeos-cache" | \
+     sudo_clobber "${FLAGS_chroot}/etc/profile.d/chromeos-cachedir.sh"
+   sudo_multi \
+       "chmod 0644 '${FLAGS_chroot}/etc/profile.d/chromeos-cachedir.sh'" \
+       "rm -rf '${FLAGS_chroot}/var/cache/distfiles'" \
+       "ln -s chromeos-cache/distfiles '${FLAGS_chroot}/var/cache/distfiles'"
 
    # Run this from w/in the chroot so we use whatever uid/gid
    # these are defined as w/in the chroot.
@@ -217,10 +231,10 @@ init_setup () {
 
    # These are created for compatibility while transitioning
    # make.conf and friends over to the new location.
-   # TODO(ferringb): remove this 03/12 or so.
+   # TODO(ferringb): remove this 01/13 or so.
-   sudo ln -s ../../cache/distfiles/host \
+   sudo ln -s ../../cache/chromeos-cache/distfiles/host \
      "${FLAGS_chroot}/var/lib/portage/distfiles"
-   sudo ln -s ../../cache/distfiles/target \
+   sudo ln -s ../../cache/chromeos-cache/distfiles/target \
      "${FLAGS_chroot}/var/lib/portage/distfiles-target"
 
    # Add chromite/bin and depot_tools into the path globally; note that the