#!/bin/bash
# These are useful, or at worst not harmful, for all images we build.

set -eu
set -o pipefail

[ -n "$ARCH" ]
[ -n "$TARGET_ROOT" ]

shopt -s extglob

DIB_CLOUD_IMAGES=${DIB_CLOUD_IMAGES:-http://cloud-images.ubuntu.com/}
DIB_RELEASE=${DIB_RELEASE:-saucy}
BASE_IMAGE_FILE=${BASE_IMAGE_FILE:-$DIB_RELEASE-server-cloudimg-$ARCH-root.tar.gz}
SHA256SUMS=${SHA256SUMS:-https://${DIB_CLOUD_IMAGES##http?(s)://}/$DIB_RELEASE/current/SHA256SUMS}
CACHED_FILE=$DIB_IMAGE_CACHE/$BASE_IMAGE_FILE

if [ -n "$DIB_OFFLINE" -a -f "$CACHED_FILE" ] ; then
    echo "Not checking freshness of cached $CACHED_FILE."
else
  echo "Fetching Base Image"
  $TMP_HOOKS_PATH/bin/cache-url $SHA256SUMS $DIB_IMAGE_CACHE/SHA256SUMS.ubuntu.$DIB_RELEASE.$ARCH
  $TMP_HOOKS_PATH/bin/cache-url $DIB_CLOUD_IMAGES/$DIB_RELEASE/current/$BASE_IMAGE_FILE $CACHED_FILE
  pushd $DIB_IMAGE_CACHE
  grep "$BASE_IMAGE_FILE" SHA256SUMS.ubuntu.$DIB_RELEASE.$ARCH | sha256sum --check -
  popd
fi
# Extract the base image (use --numeric-owner to avoid UID/GID mismatch between
# image tarball and host OS e.g. when building Ubuntu image on an openSUSE host)
sudo tar -C $TARGET_ROOT --numeric-owner -xzf $DIB_IMAGE_CACHE/$BASE_IMAGE_FILE
if [ -e "$TARGET_ROOT/lost+found" ]; then
  sudo rmdir $TARGET_ROOT/lost+found
fi