alpine-container.sh

## alpine-container.sh
#!/bin/bash -e
# Creates a systemd-nspawn container with Alpine

MIRROR=http://nl.alpinelinux.org/alpine
ARCH=x86_64
VERSION=v3.8
APKTOOLS_VERSION=2.10.0-r0


if [ $UID -ne 0 ]; then
	echo "run this script as root" >&2
	exit 1
fi

if [ -z "$1" ]; then
	echo "Usage: $0 <destination>" >&2
	exit 0
fi

dest="$1"
apkdir=$(mktemp -d)
guestarch=x86
[ "$(uname -m)" == x86_64 ] && guestarch=x86_64

wget -qO- $MIRROR/latest-stable/main/x86/apk-tools-static-$APKTOOLS_VERSION.apk \
	| tar -xz -C $apkdir || \
	{ echo "Couldn't download apk-tools, the version might have changed..."; exit 1; }

$apkdir/sbin/apk.static \
	-X $MIRROR/$VERSION/main -U --arch $guestarch \
	--allow-untrusted --root "$dest" \
	--initdb add alpine-base

mkdir -p "$dest"/{etc/apk,root}
printf '%s/%s/main\n' $MIRROR $VERSION >"$dest"/etc/apk/repositories
sed '/tty[0-9]:/ s/^/#/' -i "$dest"/etc/inittab
printf 'console::respawn:/sbin/getty 38400 console\n' >>"$dest"/etc/inittab
for s in hostname bootmisc syslog; do
	ln -s /etc/init.d/$s "$dest"/etc/runlevels/boot/$s
done
for s in killprocs savecache; do
	ln -s /etc/init.d/$s "$dest"/etc/runlevels/shutdown/$s
done


rm -r $apkdir
echo ""
echo "Alpine $VERSION container was created successfully."

## arch-container.sh
#!/bin/bash -e
# Creates a systemd-nspawn container with Arch Linux

MIRROR=http://mirror.rackspace.com/archlinux
ISO_DATE=2018.07.01
PACKAGES="base"


if [ $UID -ne 0 ]; then
	echo "run this script as root" >&2
	exit 1
fi

if [ -z "$1" ]; then
	echo "Usage: $0 <destination>" >&2
	exit 0
fi

dest="$1"
tarfile=$(mktemp)

wget $MIRROR/iso/$ISO_DATE/archlinux-bootstrap-$ISO_DATE-x86_64.tar.gz -O $tarfile
mkdir "$dest"
tar -xzf $tarfile -C "$dest" --strip-components=1

printf 'Server = %s/$repo/os/$arch\n' $MIRROR >"$dest"/etc/pacman.d/mirrorlist
systemd-nspawn -q -D "$dest" sh <<SCRIPT
pacman-key --init
pacman-key --populate archlinux

pacman -Sy
# avoid installing the kernel
pkgs=\$(pacman -Sg $PACKAGES | while read _ p;do [[ "\$p" == "linux"* ]]||echo -n "\$p ";done)
pacman -S --noconfirm --needed \$pkgs
SCRIPT


rm $tarfile
echo ""
echo "Arch $ISO_DATE container was created successfully."

## ubuntu-container.sh
#!/bin/bash -e
# Creates a systemd-nspawn container with Ubuntu
# external dependency: squashfs-tools (unsquashfs)

CODENAME=bionic
VERSION=18.04


if [ $UID -ne 0 ]; then
	echo "run this script as root" >&2
	exit 1
fi

if [ -z "$1" ]; then
	echo "Usage: $0 <destination>" >&2
	exit 0
fi

dest="$1"
filesys=$(mktemp)

[ -d "$dest" ] && rmdir "$dest"
wget "http://cloud-images.ubuntu.com/minimal/releases/$CODENAME/release/ubuntu-${VERSION}-minimal-cloudimg-amd64.squashfs" -O $filesys
unsquashfs -d "$dest" $filesys

sed '/^root:/ s|\*||' -i "$dest/etc/shadow"
rm "$dest/etc/resolv.conf"
disable="ebtables rsync systemd-timesyncd"
disable="$disable networkd-dispatcher systemd-networkd systemd-networkd-wait-online systemd-resolved"
for s in $disable; do
	rm -f "$dest/etc/systemd/system/"*.target.wants"/$s.service" "$dest"/etc/rc[S5].d/S??"$s"
done
# ssh and iscsi cause various errors, linux kernel is dead weight
systemd-nspawn -q -D "$dest" apt-get -qq purge -y openssh-server open-iscsi linux-base


rm $filesys
echo ""
echo "Ubuntu $VERSION container was created successfully."