-- psrtition the drive --

parted /dev/sda mklabel msdos
parted /dev/sda mkpart primary 1 500
parted /dev/sda set 1 boot on
parted /dev/sda mkpart primary 501 100%
parted /dev/sda set 2 lvm on

pvcreate /dev/sda2
vgcreate gentoo /dev/sda2
lvcreate -L 2G -n tmp gentoo
lvcreate -L 4G -n swap gentoo
lvcreate -L 4G -n var_log gentoo
lvcreate -l100%FREE -n root gentoo

-- setup file systems --

mkfs.ext4 /dev/sda1
mkfs.ext4 /dev/gentoo/root
mkfs.ext4 /dev/gentoo/var_log
mkfs.ext4 /dev/gentoo/tmp
mkswap /dev/gentoo/swap
swapon /dev/gentoo/swap

-- mount partitions --

mount /dev/gentoo/root /mnt
cd /mnt
mkdir -p boot tmp var/log
mount /dev/sda1 /mnt/boot
mount /dev/gentoo/var_log /mnt/var/log
mount /dev/gentoo/tmp /mnt/tmp
chmod 1777 /mnt/tmp

-- install systemd stage3 --

wget http://mirrors.linux.iu.edu/linux/gentoo/releases/amd64/autobuilds/current-stage3-amd64-systemd/stage3-amd64-systemd-20180318.tar.bz2.DIGESTS
wget http://mirrors.linux.iu.edu/linux/gentoo/releases/amd64/autobuilds/current-stage3-amd64-systemd/stage3-amd64-systemd-20180318.tar.bz2
grep 'SHA512' -A 1 stage3-amd64-systemd-20180318.tar.bz2.DIGESTS| grep -v 'CONTENTS' | grep 'stage3'
openssl dgst -r -sha512 stage3-amd64-systemd-20180318.tar.bz2

tar xpf stage3-amd64-systemd-20180318.tar.bz2 --xattrs-include='*.*' --numeric-owner
rm stage3-amd64-systemd-20180318.tar.bz2 stage3-amd64-systemd-20180318.tar.bz2.DIGESTS

-- setup portage rsync repo --

mkdir --parents /mnt/etc/portage/repos.conf
cp /mnt/usr/share/portage/config/repos.conf /mnt/etc/portage/repos.conf/gentoo.conf

-- enter systemd namespace --

sed -i -e 's/^root:\*/root:/' /mnt/etc/shadow
systemd-nspawn -bD /mnt

-- setup system locale --

locale -a | grep -i us

cat << EOF >> /etc/locale.gen
en_US ISO-8859-1
en_US.UTF-8 UTF-8
EOF

locale-gen

localectl list-locales | grep -i us
localectl set-locale LANG=en_US.utf8

localectl list-keymaps | grep -i us
localectl set-keymap us

-- set hostname -- 

hostnamectl set-hostname gentoo-systemd
echo "127.0.1.1 gentoo-systemd.localdomain gentoo-systemd" >> /etc/hosts

-- setup timezone --

timedatectl list-timezones | grep -i america
timedatectl set-timezone America/Indiana/Indianapolis
timedatectl set-ntp yes

-- leave systemd namespace --

poweroff

-- chroot into gentoo --

mount -t proc none /mnt/proc
mount --rbind /dev /mnt/dev
mount --rbind /sys /mnt/sys

chroot /mnt /bin/bash
source /etc/profile
export PS1="(chroot) $PS1"

-- setup portage --

emerge-webrsync

-- optional: update package repo to current --

emerge --sync

-- update portage if it is suggested (optional) --

emerge -1 sys-apps/portage

-- configure portage --

echo 'MAKEOPTS="-j4"' >> /etc/portage/make.conf
sed -i.bak -e 's/bindist/device-mapper/' \
	-e 's/CFLAGS="/CFLAGS="-march=native /' /etc/portage/make.conf

-- configure fstab --

cat <<EOF >> /etc/fstab
/dev/sda1               /boot           ext4            noatime         0 2
/dev/gentoo/root        /               ext4            noatime         0 1
/dev/gentoo/var_log     /var/log        ext4            noatime         0 2
/dev/gentoo/tmp         /tmp            ext4            noatime         0 2

/dev/gentoo/swap        none            swap            sw              0 0
EOF

-- optional: rebuild packages with new USE flags --

emerge -auDN @world

-- install kernel and system tools --

emerge gentoo-sources lvm2 linux-firmware genkernel-next cronie mlocate rsyslog grub
systemctl enable rsyslog
systemctl enable cronie

-- configure networkd --

cat <<EOF > /etc/systemd/network/50-dhcp_eth0.network
[Match]
Name=eth0
 
[Network]
DHCP=yes
EOF

systemctl enable systemd-networkd.service
ln -snf /run/systemd/resolve/resolv.conf /etc/resolv.conf
systemctl enable systemd-resolved.service

-- configure and compile the kernel --

sed -i.bak -e 's/^#LVM="no"/LVM="yes"/' \
    -e 's/^#MAKEOPTS="-j[1-9]"/MAKEOPTS="-j4"/' \
    -e 's/#UDEV="[A-Za-z]*"/UDEV="yes"/' /etc/genkernel.conf

genkernel --menuconfig all
  select systemd from gentoo specific init systems

-- configure and install grub --

echo 'GRUB_CMDLINE_LINUX="init=/usr/lib/systemd/systemd dolvm"' >> /etc/default/grub

grub-install /dev/sda
grub-mkconfig -o /boot/grub/grub.cfg

-- set root passwd --

passwd

-- optional: create normal user account --

useradd -m -G users,wheel,systemd-journal -s /bin/bash syseng
passwd syseng

-- reboot into gentoo system --

exit
reboot