#!/bin/bash
#
# Copyright (c) 2013 The CoreOS 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 uses Gentoo's catalyst for very thoroughly building images from scratch.
# For reference the procedure it performs is this:
#
# 1. seed: Take a recent SDK, dev container, or custom tarball as a seed to
#     build stage 1 with. Before proceeding, update relevant packages that have
#     changed sub-slot to avoid missing library issues later in the build.
#
# 2. stage1: Using the above seed tarball as a build environment, build a
#     minimal root file system into a clean directory using ROOT=... and USE=-*
#     The restricted USE flags are key be small and avoid circular dependencies.
#     NOTE that stage1 LACKS PROPER STAGE ISOLATION. Binaries produced in stage1
#     will be linked against the SEED SDK libraries, NOT against libraries built
#     in stage 1.
#
# 3. stage2: Run portage-stable/scripts/bootstrap.sh
#     This rebuilds the toolchain using Gentoo bootstrapping, ensuring it's not linked
#     to or otherwise influenced by whatever was in the "seed" tarball.
#     The toolchain rebuild may contain updated package ebuilds from
#     third_party/(portage-stable|coreos-overlay).
#     This and all following stages use portage-stable and coreos-overlay
#     from third_party/... (see 1.)
#
# 4. stage3: Run emerge -e system to rebuild everything using the fresh updated
#     toolchain from 3., using the normal USE flags provided by the profile. This
#     will also pull in assorted base system packages that weren't included
#     in the minimal environment stage1 created.
#
# 5. stage4: Install any extra packages or other desired tweaks. For the
#     sdk we just install all the packages normally make_chroot.sh does.
#
# Usage: bootstrap_sdk [stage1 stage2 etc]
# By default all four stages will be built using the latest stage4 as a seed.

SCRIPT_ROOT=$(dirname $(readlink -f "$0"))
. "${SCRIPT_ROOT}/common.sh" || exit 1

TYPE="flatcar-sdk"

. "${BUILD_LIBRARY_DIR}/catalyst.sh" || exit 1

# include upload options
. "${BUILD_LIBRARY_DIR}/release_util.sh" || exit 1


## Define the stage4 config template
catalyst_stage4() {
cat <<EOF
pkgcache_path: $BINPKGS
stage4/packages: coreos-devel/sdk-depends
stage4/fsscript: ${BUILD_LIBRARY_DIR}/catalyst_sdk.sh
stage4/root_overlay: ${ROOT_OVERLAY}
stage4/empty: /root /var/cache/edb
stage4/rm: /etc/machine-id /etc/resolv.conf
EOF
catalyst_stage_default 4
}

# Switch to HTTP because early boostrap stages do not have SSL support.
GENTOO_MIRRORS=$(portageq envvar GENTOO_MIRRORS)
GENTOO_MIRRORS="${GENTOO_MIRRORS//https:\/\//http://}"
export GENTOO_MIRRORS

catalyst_init "$@"
check_gsutil_opts
ROOT_OVERLAY=${TEMPDIR}/stage4_overlay

if [[ "$STAGES" =~ stage4 ]]; then
    info "Setting release to ${FLATCAR_VERSION}"
    rm -rf "${ROOT_OVERLAY}"
    # need to setup the lib->lib64 symlink correctly
    libdir=$(get_sdk_libdir)
    mkdir -p "${ROOT_OVERLAY}/usr/${libdir}"
    if [[ "${libdir}" != lib ]]; then
        if [[ "$(get_sdk_symlink_lib)" == "yes" ]]; then
            ln -s "${libdir}" "${ROOT_OVERLAY}/usr/lib"
        else
            mkdir -p "${ROOT_OVERLAY}/usr/lib"
        fi
    fi
    "${BUILD_LIBRARY_DIR}/set_lsb_release" \
        --root "${ROOT_OVERLAY}"
fi

# toolchain_util.sh is required by catalyst_sdk.sh
# To copy it, we need to create /tmp with the right permissions as it will be
# used in the exported chroot.
mkdir -p "${ROOT_OVERLAY}/tmp"
chmod 1777 "${ROOT_OVERLAY}/tmp"
cp "${BUILD_LIBRARY_DIR}/toolchain_util.sh" "${ROOT_OVERLAY}/tmp"


# Stage 1 uses "known-good" ebuilds (from both coreos-overlay and portage-stable)
#  to build a minimal toolchain (USE="-*") for stage 2.
#
# No package updates must happen in stage 1, so we use the portage-stable and
#  coreos-overlay paths included with the current SDK (from the SDK chroot's
#  /var/gentoo/repos/). "Current SDK" refers to the SDK we entered with
#  'cork enter', i.e. the SDK we run ./bootstrap_sdk in.
#
# Using ebuilds from the above mentioned sources will ensure that stage 1 builds
#  a minimal stage 2 from known-good ebuild versions - the same ebuild versions
#  that were used to build the very SDK we run ./bootstrap_sdk in.
#
# DANGER ZONE
#
# Stage 1 lacks proper isolation and will link all packages built for
#  stage 2 against its own seed libraries ("/" in the catalyst chroot) instead of against libraries
#  installed into the FS root of the stage 2 seed ("/tmp/stage1root" in the catalyst chroot).
#  This is why we must prevent any updated package ebuilds to "leak" into stage 1, hence we use
#  "known good" ebuild repo versions outlined above.
#
# In special circumstances it may be required to circumvent this and use custom paths
#  for either (or both) portage and overlay. The command line options
#  --stage1-portage-path and --stage1-overlay-path may be used to specify
#  a repo path known to work for stage1. In that case the stage1 seed (i.e. the seed SDK)
#  will be updated prior to starting to build stage 2.
#  NOTE that this should never be used to introduce library updates in stage 1. All binaries
#  produced in stage 1 are linked against libraries in the seed tarball, NOT libraries produced
#  by stage one. Therefore, these binaries will cease to work in stage 2 when linked against
#  outdated "seed tarball" libraries which have been updated to newer versions in stage 1.

catalyst_build

if [[ "$STAGES" =~ stage4 ]]; then
    info "Build complete! Changing output name to something more sensible."
    build_name="stage4-${ARCH}-${FLAGS_version}.tar.bz2"
    release_name="${TYPE}-${ARCH}-${FLAGS_version}.tar.bz2"
    build_image="${BUILDS}/${build_name}"
    release_image="${BUILDS}/${release_name}"
    build_contents="${build_image}.CONTENTS.gz"
    release_contents="${release_image}.CONTENTS.gz"
    build_digests="${build_image}.DIGESTS"
    release_digests="${release_image}.DIGESTS"
    ln -f "${build_image}" "${release_image}"
    ln -f "${build_contents}" "${release_contents}"
    sed -e "s/${build_name}/${release_name}/" \
        "${build_digests}" > "${release_digests}"

    # Validate we didn't break the DIGESTS with sed
    verify_digests "${release_image}" "${release_contents}"

    info "SDK ready: ${release_image}"

    def_upload_path="${UPLOAD_ROOT}/sdk/${ARCH}/${FLAGS_version}"
    sign_and_upload_files "tarball" "${def_upload_path}" "" \
        "${release_image}" "${release_contents}" "${release_digests}"
    sign_and_upload_files "packages" "${def_upload_path}" "pkgs/" \
        "${BINPKGS}"/*

    if [ -d "${BINPKGS}/crossdev" ]; then
        # Upload the SDK toolchain packages
        sign_and_upload_files "cross toolchain packages" "${def_upload_path}" \
            "toolchain/" "${BINPKGS}/crossdev"/*
    fi
fi

command_completed