#!/bin/bash -ex
. /usr/share/coreos/release

# Try to determine which channel contains this CoreOS version.
for group in stable beta alpha
do
        url="http://$group.release.core-os.net/$COREOS_RELEASE_BOARD/$COREOS_RELEASE_VERSION/coreos_developer_container.bin.bz2"
        curl --fail --head --location --silent "$url" >/dev/null && break
done

# Download, decompress, and verify the developer container image.
gpg2 --recv-keys 04127D0BFABEC8871FFB2CCE50E0885593D2DCB4
curl --fail --location "$url" |
    tee >(bzip2 --decompress > coreos_developer_container.bin) |
    gpg2 --verify <(curl --location --silent "$url.sig") -

# Run the build scripts in the container with the host modules directory.
systemd-nspawn \
    --bind=/lib/modules \
    --image=coreos_developer_container.bin \
    /bin/bash -ex <<- 'EOF'
	. /usr/share/coreos/release
	
	# Check out the current CoreOS version's ebuilds.
	emerge-gitclone
	git -C /var/lib/portage/coreos-overlay \
	    checkout "build-${COREOS_RELEASE_VERSION%%.*}" ||
	    :  # Stay on master if this version hasn't branched yet.
	
	# Prepare the Linux kernel source for building external modules.
	emerge -gKv coreos-sources
	gzip -cd /proc/config.gz > /usr/src/linux/.config
	make -C /usr/src/linux modules_prepare
	
	# Run any build scripts.
	shopt -s nullglob
	for project in /lib/modules/auto-update-kmods.d/*.sh
	do
	        (. "$project")
	done
	
	# Update the kernel module dependency files.
	depmod
	EOF

# Delete the developer container to save space.
rm --force coreos_developer_container.bin