manjaro2archcachy/attempt_1.sh

#!/usr/bin/bash

# Yes, this is a disaster of a bash script.
# I'm really hacking things together here.

# Fail on command failure.
# This acts funky, and prevents failure on reserved words like:
#
# "The  -e  setting shall be ignored when executing the compound list following the
# while, until, if, or elif reserved word, a pipeline beginning with the !  reserved word,
# or any command of an AND-OR list other than the last." - set man page
#set -e

RED='\e[31m'
GREEN='\e[32m'

assert() {
    if ! $1; then
        echo "Script depends on $2 to function, please resolve manually."
    fi

    # Yes, this is always true, but anyway.
    return $1
}

is_installed() {
    return ! which "$1" > /dev/null
}

run_unprivileged() {
    sudo -u "$USERNAME" "$@"
}

log() {
    if "$1"; then
        echo -e "$2...${GREEN}yes $3"
    else
        echo -e "$2...${RED}no"
    fi
}

# Checks

[ $(id -u) = 0 ]
if ! $?; then
    echo "Script must be run with elevated permissions."
    exit 1
fi

# As much as I highly doubt that pacman, curl, lspci, and mhwd-kernel will be missing,
# might as well do the easy check.
#
# Also, if sudo cannot be called, the user might be using doas, in which case they'll need to fix
# their aliases or patch the privilege drop for run_unprivileged.

SUDO=$(is_installed sudo)
PACMAN=$(is_installed pacman)
YAY=$(is_installed yay)
CURL=$(is_installed curl)
LSPCI=$(is_installed lspci)
REFLECTOR=$(is_installed reflector)
MHWD_KERNEL=$(is_installed mhwd-kernel)
DKMS=$(is_installed dkms)

log $(assert $SUDO "sudo") "sudo"
log $(assert $PACMAN "pacman") "pacman"
log $YAY "yay"
log $CURL "curl"
log $(assert $LSPCI "lspci") "lspci"
log $REFLECTOR "reflector"
log $(assert $MHWD_KERNEL "mhwd-kernel") "mhwd-kernel"
log $DKMS "dkms"

pacman -Qs pamac
PAMAC=$?

USERNAME=$(logname)
[ $#USERNAME > 0]
log $? "unprivileged_user" "$USERNAME"

[ $(lspci | grep "VGA" | grep "nvidia") > 0 ]
NVIDIA_GPU=$?
log $NVIDIA_GPU "nvidia_gpu"

# Identify installed Manjaro kernels
mhwd_dump=$(mhwd-kernel -li | grep "linux")

re="linux\d+"

ACTIVE_KERNEL=$(echo "$mhwd_dump" | grep "running" | grep -Po "$re" )
ALTERNATE_KERNELS=$(echo "$mhwd_dump" | grep -Po "$re" | grep -v "$ACTIVE_KERNEL")

[ $#ACTIVE_KERNEL > 0]
log $? "active_kernel" "$ACTIVE_KERNEL"

[ $#ALTERNATE_KERNELS > 0 ]
log $? "alternate_kernels"

# no dkms, no propagation
# dkms, no nvidia, guaranteed propagation
# dkms, w/ nvidia, possible propagation
PROPAGATE_DKMS=$DKMS
if $DKMS && $NVIDIA_GPU; then
    [ $(dkms status | grep -v "nvidia") > 0 ]
    PROPAGATE_DKMS=$?
fi

log "$PROPAGATE_DKMS" "propagate_dkms"

# Prep
pacman -Syy

if $PAMAC; then
    echo "Pamac is installed, removing..."
    # TODO: Uninstall pamac if present
fi

if ! $YAY; then
    echo "Yay is not installed, calling: pacman -S yay"
    pacman -S yay

    assert $(is_installed yay) "yay"

    run_unprivileged yay -Syy
fi

if ! $CURL; then
    echo "Curl is not installed, calling: pacman -S curl"
    pacman -S curl

    assert $(is_installed curl) "curl"
fi

if ! $REFLECTOR; then
    echo "Reflector is not installed, calling: yay -S reflector"
    run_unprivileged yay -S reflector

    assert $(is_installed reflector) "reflector"
fi

# Configure new mirrorlists

# CachyOS
# See: https://wiki.cachyos.org/features/optimized_repos/#adding-our-repositories-to-an-existing-arch-linux-install

cd $(mktemp -d)
curl https://mirror.cachyos.org/cachyos-repo.tar.xz -o cachyos-repo.tar.xz
tar xvf cachyos-repo.tar.xz
cd cachyos-repo

# Just in case, ensure the script can be executed.
if [[ ! -x "cachyos-repo.sh" ]]; then
    chmod +x cachyos-repo.sh
fi

./cachyos-repo.sh

# Arch
# Backup the old Manjaro mirrorlist
DEFAULT_MIRRORLIST='/etc/pacman.d/mirrorlist'

mv $DEFAULT_MIRRORLIST "$DEFAULT_MIRRORLIST.bak"
curl -o "$DEFAULT_MIRRORLIST" https://archlinux.org/mirrorlist/all/

reflector\
    --fastest 32\
    --protocol https\
    --sort rate\
    --country CA,NZ,DE,NL,PL,SE\
    --save /etc/pacman.d/mirrorlist

pacman -Syy

# Install new kernel

DEFAULT_KERNEL="linux-cachyos"
PROPAGATE_MANJARO="Keep all currently installed Manjaro kernels"

# yes, they're hard-coded. For now at least.
KNOWN_KERNELS=(
    "$PROPAGATE_MANJARO",
    "linux",
    "linux-lts",
    "linux-hardened",
    "linux-rt",
    "linux-cachyos",
    "linux-cachyos-lts",
    "linux-cachyos-hardened",
    "linux-cachyos-bore",
    "linux-cachyos-eevdf",
    "linux-cachyos-bmq",
    "linux-cachyos-deckify",
    "linux-cachyos-rc",
    "linux-cachyos-rt-bore",
    "linux-cachyos-server",
    "linux-zen"
    #"linux-cachyos-cacule",
    #"linux-cachyos-debug",
    #"linux-cachyos-gcc",
)

echo "INSTALL NEW KERNEL"
echo "Warning: All options except 0 will remove all Manjaro kernels except the active one."
echo "         If you have no additional kernels installed, then this will do nothing."
echo "Note: Multiple options can be chosen with comma separation."
echo

# List KNOWN_KERNELS
for idx in "${!KNOWN_KERNELS[@]}"; do
    printf "%s\t%s\n" "$idx" "${KNOWN_KERNELS[$idx]}"
done

# Print default kernel selection
for idx in "${!KNOWN_KERNELS[@]}"; do
    if [[ "${KNOWN_KERNELS[$idx]}" == "$DEFAULT_KERNEL" ]]; then
        printf "Default: %s (%s)" "$idx" "$DEFAULT_KERNEL"
        kernels="$idx"
    fi
done

echo -n "Kernel(s): "
read -r tmp

if [[ ${#tmp} > 0 ]]; then
    # Credit to bgoldst on StackOverflow for this solution.
    # https://stackoverflow.com/questions/10586153/how-to-split-a-string-into-an-array-in-bash
    kernels=$(readarray -td, a <<< "$tmp,"; unset 'a[-1]'; declare -p a)
fi

if [[ $ALTERNATE_KERNELS > 0 ]]; then
    # Determine if the user wants to maintain the installed kernel(s).
    for idx in "${kernels}"; do
        if [[ "${KNOWN_KERNELS[$idx]}" == "$PROPAGATE_MANJARO" ]]; then
            run_unprivileged yay -R "${ALTERNATE_KERNELS[@]}"
            break
        fi
    done
fi

# TODO: Install kernels
# TODO: dkms module propagation
# TODO: Remove DKMS if only present for nvidia-dkms [ ! $PROPAGATE_DKMS ]
# TODO: Kill Orphans