balena-supervisor/base-image/build.sh

#!/bin/bash

set -o errexit

BUILD_DIR='/home/builder/tmp'

case "$ARCH" in
'amd64')
	export TARGET_MACHINE='generic-x86-64'
;;
'i386')
	export TARGET_MACHINE='generic-x86'
;;
'rpi')
	export TARGET_MACHINE='generic-armv6'
;;
'armv7hf')
	export TARGET_MACHINE='generic-armv7hf'
;;
'armel')
	export TARGET_MACHINE='generic-armv5'
;;
'aarch64')
	export TARGET_MACHINE='generic-armv8'
;;
esac

export SOURCE_DIR=/source
export DEST_DIR=/dest
export SHARED_DOWNLOADS=/yocto/shared-downloads
export SHARED_SSTATE=/yocto/shared-sstate
# Make sure shared directories are in place
mkdir -p $SHARED_DOWNLOADS
mkdir -p $SHARED_SSTATE
mkdir -p $DEST_DIR

groupadd -g $BUILDER_GID builder
useradd -m -u $BUILDER_UID -g $BUILDER_GID builder
sudo -H -u builder \
	/bin/bash -c "mkdir -p $BUILD_DIR \
	&& cp -r $SOURCE_DIR/* $BUILD_DIR/ \
	&& cd $BUILD_DIR \
	&& source oe-core/oe-init-build-env build bitbake \
	&& DL_DIR=$SHARED_DOWNLOADS SSTATE_DIR=$SHARED_SSTATE MACHINE=$TARGET_MACHINE $BUILD_DIR/bitbake/bin/bitbake core-image-minimal > /dev/null"
tar xzf $BUILD_DIR/build/tmp-glibc/deploy/images/$TARGET_MACHINE/core-image-minimal-$TARGET_MACHINE.tar.gz  -C $DEST_DIR
# Delete the sstate and downloads directory so that the resulting image isn't huge
# If https://github.com/moby/moby/issues/32507 gets implemented we can start using
# a bind mounted cached directory instead
rm -rf $SHARED_DOWNLOADS
rm -rf $SHARED_SSTATE
rm -rf $BUILD_DIR