chroot-build.sh

#!/bin/sh

################################################################################
# Builds age-plugin-se in a Debian chroot, and copies the binary
# and all its dynamically loaded libraries into the destination dir.
#
# Has to be run as root
################################################################################

set -e

NAME=age-plugin-se
BIN_NAME=$NAME

# Sources directories necessary for the build. 
# These will be copied to the chroot.
SOURCES="Sources Tests Package.swift"

# List of dynamic libraries the resulting binary depends upon
# These will be bundled, together with the dynamic linker
LIBS="libm.so.6 libstdc++.so.6 libgcc_s.so.1 libc.so.6"

if [ -z "$PREFIX" ]; then
  PREFIX=/usr/local
fi
if [ -z "$DESTDIR" ]; then
  DESTDIR=.build/chroot-build
fi

ARCH=$(uname -m)
CHROOT_DIR=/mnt/$NAME-build-chroot
CHROOT_BUILD_DIR=/opt/build


if [ "$ARCH" == "aarch64" ]; then
  SWIFT_PACKAGE_SUFFIX=-aarch64
  LINKER=ld-linux-aarch64.so.1
else
  SWIFT_PACKAGE_SUFFIX=
  LINKER=ld-linux-x86-64.so.2
fi

SWIFT_PACKAGE_URL=https://download.swift.org/swift-5.10.1-release/debian12$SWIFT_PACKAGE_SUFFIX/swift-5.10.1-RELEASE/swift-5.10.1-RELEASE-debian12$SWIFT_PACKAGE_SUFFIX.tar.gz
SWIFT_DIR=/usr/local/swift-5.10.1-RELEASE-debian12$SWIFT_PACKAGE_SUFFIX
SWIFT=$SWIFT_DIR/usr/bin/swift

################################################################################
# Create Debian chroot
################################################################################

if [ ! -d "$CHROOT_DIR" ]; then
  mkdir -p $CHROOT_DIR
  /usr/sbin/debootstrap --variant=minbase stable $CHROOT_DIR https://deb.debian.org/debian/
fi


################################################################################
# Install swift (+dependencies) in the chroot
################################################################################

if [ ! -d "$CHROOT_DIR$SWIFT_DIR" ]; then
  wget -q -O - $SWIFT_PACKAGE_URL | tar -C $CHROOT_DIR/usr/local -x -v -z 
fi
echo -e "$SWIFT_DIR/usr/lib/swift/linux\\n$SWIFT_DIR/usr/lib/swift/host" > $CHROOT_DIR/etc/ld.so.conf.d/swift.conf
/usr/sbin/chroot $CHROOT_DIR sh -c 'apt-get update && apt-get -y install sqlite3 libncurses6 libcurl4 libxml2 binutils libc6-dev libgcc-12-dev git libstdc++-12-dev'


################################################################################
# Add sources to the chroot
################################################################################

mkdir -p $CHROOT_DIR$CHROOT_BUILD_DIR
rsync --delete -a $SOURCES $CHROOT_DIR$CHROOT_BUILD_DIR


################################################################################
# Build in the chroot
################################################################################

/usr/sbin/chroot $CHROOT_DIR sh -c "mount -t proc /proc proc/"

set +e
/usr/sbin/chroot $CHROOT_DIR sh -c "set -e; cd $CHROOT_BUILD_DIR && $SWIFT build -c release --static-swift-stdlib -Xlinker -rpath='\$ORIGIN'/../lib/$NAME  -Xlinker '--dynamic-linker=$PREFIX/lib/$NAME/$LINKER' && cp \$($SWIFT build -c release --show-bin-path)/$BIN_NAME ."
set -e

/usr/sbin/chroot $CHROOT_DIR sh -c "umount /proc"


################################################################################
# Copy all files from the chroot to the target dir
################################################################################

mkdir -p $DESTDIR$PREFIX/bin $DESTDIR$PREFIX/lib/$NAME
cp $CHROOT_DIR$CHROOT_BUILD_DIR/$BIN_NAME $DESTDIR$PREFIX/bin
cp $CHROOT_DIR/lib/$ARCH-linux-gnu/$LINKER $DESTDIR$PREFIX/lib/$NAME
for lib in $LIBS; do
  cp $CHROOT_DIR/lib/$ARCH-linux-gnu/$lib $DESTDIR$PREFIX/lib/$NAME
done