Gentoo libvirt VM install

#!/bin/sh

DOMNAME="$1"
STAGE_TBZ="$2"
KERNEL_PKG="$3"

if [ -z "${DOMNAME}" ]; then
    echo "usage: ${0##*/} name [stage_tarball [kernel_pkg]]"
    exit 2
fi

unset $(env | awk -F= '/^LC_/{print $1}')
export LC_ALL=C

set -e


: ${POOL:=default}
: ${HOSTNAME:=$(printf ${DOMNAME} | tr '[A-Z]' '[a-z]')}
: ${BINPKG_DIR:=default-linux/amd64/amdfam10}
: ${PORTAGE_PROFILE=default/linux/amd64/13.0}

mountpoint=${TMPDIR:-/tmp}/${HOSTNAME}
mkdir ${mountpoint}

virsh vol-create-as ${POOL} ${DOMNAME}.img ${VDISKSIZE:-6G}
vol_path=$(virsh vol-path ${DOMNAME}.img ${POOL})

i=$(pgrep -fa ^nbd | sed -r 's/[0-9]+\s+nbd//' | sort -nr | head -n1)
blkdev=/dev/nbd$((${i:--1} + 1))
unset i

echo 'Creating logical volumes and filesystems ...'
sudo /bin/sh -e <<EOS
qemu-nbd -c ${blkdev} ${vol_path}

sgdisk -a 4096 -Z -g \
    -n 1::+1M \
    -t 1:EF02 \
    -c 1:'BIOS boot partition' \
    -n 2::+32M \
    -c 2:'Linux filesystem' \
    -n 3:: \
    -t 3:8E00 \
    -c 3:'Linux LVM' \
    ${blkdev}

pvscan > /dev/null

pvcreate ${blkdev}p3
vgcreate ${HOSTNAME} ${blkdev}p3
lvcreate -nswap -L1G ${HOSTNAME}
lvcreate -nroot -L300M ${HOSTNAME}
lvcreate -nusr -L1200M ${HOSTNAME}
lvcreate -nvar -L400M ${HOSTNAME}
lvcreate -nopt -L100M ${HOSTNAME}
lvcreate -nhome -L100M ${HOSTNAME}
mkswap -Lswap /dev/${HOSTNAME}/swap
mkfs.ext4 -q -Lboot ${blkdev}p2
for v in root usr var opt home; do
    mkfs.xfs -q -L\$v /dev/${HOSTNAME}/\$v
done
EOS

[ -z "${STAGE_TBZ}" ] && exit 0

echo 'Mounting filesystems ...'
sudo /bin/sh -e <<EOS
mount /dev/${HOSTNAME}/root ${mountpoint}

install -d ${mountpoint}/boot
mount ${blkdev}p2 ${mountpoint}/boot

for v in usr var opt home; do
    install -d ${mountpoint}/\$v
    mount /dev/${HOSTNAME}/\$v ${mountpoint}/\$v
done
EOS

echo 'Extracting stage tarball ...'
sudo tar -xaf "${STAGE_TBZ}" -C ${mountpoint}

portdir=$(portageq repos_config / | python3 -c '
import configparser, sys
c = configparser.ConfigParser()
c.read_file(sys.stdin)
s = c["DEFAULT"]["main-repo"]
print(c[s]["location"])
')
distdir=$(portageq envvar DISTDIR)
while ! mountpoint -q ${pkgdir:=$(portageq envvar PKGDIR)}; do
    pkgdir=${pkgdir%/*}
    test -n "${pkgdir}"
done

echo 'Configuring portage ...'
sudo /bin/sh -e <<EOS
cd ${mountpoint}
rm -rf run/openrc
mount -t proc proc proc
mount -t sysfs sysfs sys
mount -t tmpfs tmpfs tmp
mount -t tmpfs tmpfs run
mount -obind /dev dev
mount -obind /dev/pts dev/pts
mount -obind /dev/shm dev/shm

install -d \
    var/cache/portage/tree \
    var/cache/portage/distfiles \
    var/cache/portage/binpkgs
mount -obind ${portdir} var/cache/portage/tree
mount -obind ${distdir} var/cache/portage/distfiles
mount -obind ${pkgdir} var/cache/portage/binpkgs

cd ${mountpoint}/etc/portage
rm -rf repos.conf
mkdir repos.conf
sed -r -e s@/usr/portage@/var/cache/portage/tree@ \
    < /usr/share/portage/config/repos.conf \
    > repos.conf/gentoo.conf

rm -rf make.conf
mkdir make.conf
cat > make.conf/00_base.conf <<EOF
CHOST="x86_64-pc-linux-gnu"
CFLAGS="-O2 -pipe"
CXXFLAGS="\${CFLAGS}"

DISTDIR="${distdir}"
PKGDIR="${pkgdir}"

EMERGE_DEFAULT_OPTS="--usepkg --jobs --load-average=3 --quiet-fail=y"
FEATURES=""
MAKEOPTS="-j9"
EOF
cat > make.conf/05_default-use.conf <<EOF
USE="caps -cups filecaps -gpm"
EOF
cat > make.conf/10_cpu-flags.conf <<EOF
CPU_FLAGS_X86="3dnow 3dnowext mmx mmext sse sse2"
EOF
EOS

echo 'Configuring host ...'
sudo chroot ${mountpoint} /bin/sh -e <<EOS
env-update

eselect profile set ${PORTAGE_PROFILE}

FEATURES=-news emerge --noreplace --quiet grub xfsprogs
grub2-install ${blkdev}
cat > /boot/grub/grub.cfg <<EOF
timeout=1

menuentry 'Gentoo Linux' {
    root=hd0,gpt2
    linux /vmlinuz root=/dev/${HOSTNAME}/root dolvm net.ifnames=0 quiet
    initrd /initramfs
}
EOF

sed -i s/localhost/${HOSTNAME}/ /etc/conf.d/hostname

cat > /etc/fstab <<EOF
LABEL=swap  none    swap    sw  0 0
LABEL=boot  /boot   ext4    noauto,noatime  1 2
/dev/${HOSTNAME}/root   /   xfs ro,noatime  0 1
/dev/${HOSTNAME}/usr    /usr    xfs ro,noatime  0 2
/dev/${HOSTNAME}/var    /var    xfs noatime 0 2
/dev/${HOSTNAME}/opt    /opt    xfs ro,noatime  0 2
/dev/${HOSTNAME}/home   /home   xfs noatime 0 2
tmpfs   /tmp    tmpfs   defaults    0 0
EOF

ln -snf /proc/self/mounts /etc/mtab
ln -snf /run/resolv.conf /etc/resolv.conf
ln -snf /run/ntp.conf /etc/ntp.conf

passwd -d root
EOS

if [ -n "${KERNEL_PKG}" ]; then
    echo 'Extracting kernel package ...'
    sudo tar --no-same-owner --no-same-permissions --strip-components=1 \
        -xaf "${KERNEL_PKG}" -C ${mountpoint}
fi

echo 'Cleaning up ...'
awk '$5~/'${HOSTNAME}'/{print $5}' /proc/self/mountinfo | tac \
    | xargs sudo umount
sudo vgchange -an ${HOSTNAME}
sudo qemu-nbd -d ${blkdev}

virt-install --name ${DOMNAME} \
    --ram ${VRAM:-1024} \
    --vcpus ${VCPUS:-2} \
    --os-type linux \
    --os-variant rhel7 \
    --boot hd \
    --disk ${vol_path} \
    --network bridge=${VNET:-br0} \
    --graphics vnc \
    --video cirrus \
    --memballoon model=virtio \
    --noautoconsole

rmdir ${mountpoint}