Using mkosi and AUR to install packages

mkosi.build.chroot

#!/usr/bin/env bash
set -ex

PACKAGES=(
    neovim-git
)

# All this is basically to get around makepkg calling pacman with sudo
# Otherwise we could just call `aur sync` and be done with it

cd /tmp

pacman_deps=$(aur depends ${PACKAGES[@]} --json --all | jq -r '.[] | select(.ID == null) | .Name')
pacman -S --needed --noconfirm ${pacman_deps[@]}

# We install needed deps in topological order using tsort
aur_deps=$(aur depends ${PACKAGES[@]} -r | tsort)

aur fetch ${aur_deps[@]}
for pkg in ${aur_deps[@]}; do
    pushd ${pkg}
    sudo -u nobody BUILDDIR="/tmp/build" SRCDEST="/tmp/build" aur build --no-sync
    pacinstall --dbsync --no-confirm --yolo ${pkg}
    popd
done

# Move what we actually need into the image
cp -r --no-preserve=ownership /aur ${DESTDIR}
cp --parents /etc/pacman.d/aur.conf ${DESTDIR}

reflector --latest 5 --sort rate --save ${DESTDIR}/etc/pacman.d/mirrorlist

mkosi.postinst.chroot

#!/usr/bin/env bash
set -ex

# Setup pacman to read modular configs
mkdir -p /etc/pacman.d
echo > /etc/pacman.d/dummy.conf "# This exists just so /etc/pacman.d is never empty and we can Include = /etc/pacman.d/*.conf"
echo -e "\nInclude = /etc/pacman.d/*.conf" >> /etc/pacman.conf

# Configure pacman
pacman-key --init
pacman-key --populate

# Install the aur packages we just built
pacman -Sy
pacinstall --dbsync \
    --no-confirm \
    --yolo \
    $(pacman -Sql aur)

mkosi.prepare.chroot

#!/usr/bin/env bash
set -e

if [[ "${1}" != "build" ]]; then
    exit 0
fi

# Setup pacman
reflector --latest 5 --sort rate --save /etc/pacman.d/mirrorlist
pacman-key --init
pacman-key --populate

cd /tmp

# Manually build and install aurutils
sudo -u nobody git clone https://aur.archlinux.org/aurutils.git
pushd aurutils
(
  source ./PKGBUILD
  pacman -S \
      --needed \
      --noconfirm \
      "${makedepends[@]}" "${depends[@]}" "${checkdepends[@]}"
)
sudo -u nobody PKGDEST="/tmp" PKGEXT=".pkg.tar" makepkg --clean --cleanbuild
popd

pacman -U --noconfirm /tmp/aurutils-*.pkg.tar

# Add local repo reference
echo > /etc/pacman.d/aur.conf "
[aur]
SigLevel = Optional TrustAll
Server = file:///aur"
echo -e "\nInclude = /etc/pacman.d/*.conf" >> /etc/pacman.conf

# Create empty repository
# All the arch tooling assumes we can use sudo when we can't here
# so we own this repo as -u nobody and call pacman explicitly

install -d /aur -o nobody
sudo -u nobody tar -ca -f /aur/aur.db.tar.xz -T /dev/null
sudo -u nobody ln -s /aur/aur.db.tar.xz /aur/aur.db

pacman -Sy