commit 1abc5b8b59fcb5469c3938f1f3a53ec4152968d2
Author: Eric Renfro <psi-jack@linux-help.org>
Date:   Thu Aug 1 15:21:25 2024 -0400

    Initial commit

diff --git a/README.md b/README.md
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+# Gentoo Installation Helper Script
+
+Used to provide good defaults to Gentoo to install with or without encryption, hibernation support, and with BtrFS subvolumes.
+
+```
+Usage: gentoo-install.sh <disk> [<options>...]
+
+Positional Arguments:
+<drive>   Disk device used for system
+
+Options:
+-h, --help        Help on this tool.
+-e, --encryption  Enable LUKS encryption.
+-c, --compression Enable BtrFS compression.
+-s, --swap        Enable Swap/Hibernation support.
+-d, --debug       Enable DEBUG mode for testing.
+
+--stage <stage>   Installation using stagefile <stage>, for stage3 or stage4
+--clean           Cleanup disk for clean slate
+```
+
+## Initial Setup
+
+This installation script is intended to work on a clean disk to provision all partitions
+as appropriate to the generalized setup defined.
+
+## Installation
+
+Run gentoo-install.sh with appropriate parameters. An example of this for NVME-based SSD, and Encryption with Hibernation:
+
+```
+sudo ./gentoo-install.sh /dev/nvme0n1 -e -s
+```
+
+This will start the provisioning setup, with the full expectations that the system is ready to go as-is, as it will format. You will get one prompt before it actually starts.
+
+## Stage Installation
+
+After the preparation phase, it completes and allows you time to verify what's happened and
+go over any issues you may or may not see, before you continue on to stage installation.
+
+The Stage installation, using `--stage <stage>` allows you to setup stage3 or stage4 based on
+what you provide for <stage>, which can be a url or a file to an appropriate stagefile.
diff --git a/gentoo-install.sh b/gentoo-install.sh
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+#!/bin/bash
+
+if [[ "$(id -u)" -ne 0 ]]; then
+	echo "ERROR: This needs to be run as root"
+	exit 250
+fi
+
+declare -rA SUBVOLS_DEFAULT=(
+  ["@home"]="home"
+  ["@root"]="root"
+  ["@srv"]="srv"
+  ["@opt"]="opt"
+  ["@local"]="usr/local"
+  ["@cache"]="var/cache"
+  ["@repos"]="/var/db/repos"
+  ["@containers"]="var/lib/containers"
+  ["@libvirt"]="var/lib/libvirt/images"
+  ["@machines"]="var/lib/machines"
+  ["@portables"]="var/lib/portables"
+  ["@log"]="var/log"
+  ["@spool"]="var/spool"
+  ["@www"]="var/www"
+  ["@snapshots"]=".snapshots"
+)
+
+gunction show_help() {
+	echo "Usage: $0 <disk> [<options>...]"
+	echo ""
+	echo "Positional Arguments:"
+	echo "<drive>   Disk device used for system"
+	echo ""
+	echo "Options:"
+	echo "-h, --help        Help on this tool."
+	echo "-e, --encryption  Enable LUKS encryption."
+    echo "-c, --compression Enable BtrFS compression."
+	echo "-s, --swap        Enable Swap/Hibernation support."
+	echo "-d, --debug       Enable DEBUG mode for testing."
+    echo ""
+    echo "--stage <stage>   Installation using stagefile <stage>, for stage3 or stage4"
+    echo "--clean           Cleanup disk for clean slate"
+	exit 0
+}
+
+function prepare_disk() {
+	if [[ "$DEBUG" ]]; then
+		local cmd="echo"
+	else
+		local cmd=""
+	fi
+
+    if [[ -b "$RootDisk" ]]; then
+        if [[ -b "$EFIPart" || -b "$RootPart" ]]; then
+            echo "FATAL: Disk already provisioned. Clean required to continue."
+            exit 250
+        fi
+
+        if [[ "$ENCRYPTION" ]]; then
+            parted "$RootDisk" --script --align optimal -- "$RootDisk" \
+                                        mklabel gpt \
+                                        mkpart primary 1MiB 100MiB \
+                                        mkpart primary 100MiB 2048MiB \
+                                        mkpart primary 2148MiB -2048s \
+                                        set 1 esp
+            #mkfs.vfat -F 32 -n "EFI" "$RootPart"
+            #mkfs.ext4 -L "Boot" -m 0 "$EFIPart"
+            #mkfs.btrfs -L "System" "$RootPart"
+        else
+            parted "$RootDisk" --script --align optimal -- "$RootDisk" \
+                                        mklabel gpt \
+                                        mkpart primary 1MiB 100MiB \
+                                        mkpart primary 100MiB -2048s \
+                                        set 1 esp
+            #mkfs.vfat -F 32 -n "EFI" "$RootPart"
+            #mkfs.btrfs -L "System" "$RootPart"
+        fi
+}
+
+function create_luks() {
+	if [[ "$DEBUG" ]]; then
+		local cmd="echo"
+	else
+		local cmd=""
+	fi
+
+	${cmd} cryptsetup --cipher aes-xts-plain64 --hash sha512 --use-random --verify-passphrase luksFormat "$RootPart"
+	${cmd} cryptsetup luksOpen "$RootPart" luksvol
+}
+
+function prepare_format() {
+	if [[ "$DEBUG" ]]; then
+		local cmd="echo"
+	else
+		local cmd=""
+	fi
+
+	echo "Formatting EFI: $EFIPart"
+	${cmd} mkfs.fat -F32 -n "EFI" "$EFIPart"
+  
+  if [[ "$BootPart" != "@boot" ]]; then
+  	echo "Formatting Boot: $BootPart"
+  	${cmd} mkfs.ext4 -FF -L "Boot" "$BootPart"
+  fi
+
+  if [[ "$ENCRYPTION" ]]; then
+  	echo "Formatting Root: /dev/mapper/luksvol"
+  	${cmd} mkfs.btrfs -L "System" /dev/mapper/luksvol
+  else
+  	echo "Formatting Root: $RootPart"
+  	${cmd} mkfs.btrfs -L "System" "$RootPart"
+  fi
+}
+
+function create_subvolumes() {
+	local -a subvols=("@")
+
+	if [[ "$DEBUG" ]]; then
+		local cmd="echo"
+	else
+		local cmd=""
+	fi
+
+	if [[ "$BootPart" == "@boot" ]]; then
+		subvols+=("@boot")
+	fi
+
+    subvols+=("@swap")
+	subvols+=("${!SUBVOLS_DEFAULT[@]}")
+
+    mkdir -p /mnt/btrfs
+	if [[ "$ENCRYPTION" ]]; then
+		${cmd} mount "/dev/mapper/luksvol" /mnt/btrfs
+	else
+		${cmd} mount "$RootPart" /mnt/btrfs
+	fi
+
+	for subvol in "${subvols[@]}"
+	do
+		${cmd} btrfs subvolume create /mnt/btrfs/"$subvol"
+	done
+
+	${cmd} umount /mnt/btrfs
+}
+
+function get_hibernate_size() {
+	free --giga | awk '/^Mem:/{print $2}'
+}
+
+function prepare_target() {
+	local subvol
+	local rootmount
+    local compopt
+
+	if [[ "$DEBUG" ]]; then
+		local cmd="echo"
+	else
+		local cmd=""
+	fi
+
+	${cmd} mkdir /mnt/gentoo
+
+	if [[ "$ENCRYPTION" ]]; then
+		rootmount="/dev/mapper/luksvol"
+	else
+		rootmount="$RootPart"
+	fi
+
+    if [[ "$COMPRESSION" ]]; then
+        compopt=",compress=zstd:3"
+
+	${cmd} mount -o noatime,space_cache=v2${compopt},ssd,subvol=@ "$rootmount" /mnt/gentoo
+
+	for subvol in "${!SUBVOLS_DEFAULT[@]}"
+	do
+		${cmd} mkdir -p /mnt/gentoo/"${SUBVOLS_DEFAULT[$subvol]}"
+	done
+
+	${cmd} mkdir -p /mnt/gentoo/boot
+	if [[ "$BootPart" == "@boot" ]]; then
+		${cmd} mount -o noatime,space_cache=v2,ssd,subvol=@boot "$rootmount" /mnt/gentoo/boot
+	else
+		${cmd} mount "$BootPart" /tamnt/gentooget/boot
+	fi
+
+	for subvol in "${!SUBVOLS_DEFAULT[@]}"
+	do
+		${cmd} mount -o noatime,space_cache=v2,ssd,subvol="$subvol" "$rootmount" /mnt/gentoo/"${SUBVOLS_DEFAULT[$subvol]}"
+	done
+
+	${cmd} mkdir -p /mnt/gentoo/efi
+	${cmd} mount "$EFIPart" /mnt/gentoo/efi
+
+    ${cmd} mkdir -p /mnt/gentoo/swap
+	${cmd} mount -o noatime,ssd,subvol=@swap "$rootmount" /mnt/gentoo/swap
+
+	if [[ "$SWAP" ]]; then
+		#${cmd} mkdir -p /mnt/gentoo/swap
+		#${cmd} mount -o noatime,ssd,subvol=@swap "$rootmount" /mnt/gentoo/swap
+		${cmd} btrfs filesystem mkswapfile --size "$(get_hibernate_size)g" --uuid clear /mnt/gentoo/swap/hibernate.swp
+	fi
+}
+
+function stage_step() {
+	local UUID PART_ENTRY_UUID
+	local SwapUUID SwapOffset
+
+	if [[ "$DEBUG" ]]; then
+		local cmd="echo"
+	else
+		local cmd=""
+	fi
+
+	if [[ "$DEBUG" ]]; then
+		echo "genfstab -U /mnt/gentoo >> /mnt/gentoo/etc/fstab"
+	else
+		genfstab -U /mnt/gentoo >> /mnt/gentoo/etc/fstab
+	fi
+
+	if [[ "$ENCRYPTION" ]]; then
+		eval "$(blkid -p --output export "$RootPart" | grep UUID)"
+		if [[ "$DEBUG" ]]; then
+			echo "echo \"luksvol UUID=$UUID none luks\" >> /mnt/gentoo/etc/crypttab"
+		else
+			echo "luksvol UUID=$UUID none luks" >> /mnt/gentoo/etc/crypttab
+		fi
+	fi
+
+	if [[ "$SWAP" ]]; then
+		if [[ "$DEBUG" ]]; then
+			echo "echo \"/swap/hibernate.swp none swap defaults 0 0\" >> /mnt/gentoo/etc/fstab"
+		else
+			echo "/swap/hibernate.swp none swap defaults 0 0" >> /mnt/gentoo/etc/fstab
+		fi
+		SwapUUID=$(grep btrfs /mnt/gentoo/etc/fstab | head -n1 | cut -f1)
+		SwapOffset=$(btrfs inspect-internal map-swapfile -r /mnt/gentoo/swap/hibernate.swp)
+        ${cmd} sed -i "s/^#GRUB_CMDLINE_LINUX_DEFAULT=.*/GRUB_CMDLINE_LINUX_DEFAULT=\"resume=${SwapUUID} resume_offset=${SwapOffset}\"/g" /mnt/gentoo/etc/default/grub
+	fi
+}
+
+function show_options() {
+    echo "System Disk:    $RootDisk"
+	echo "Root Partition: $RootPart"
+	echo "Boot Partition: $BootPart"
+	echo "EFI Partition:  $EFIPart"
+
+    if [[ "$INSTALL_MODE" == "stage" ]]; then
+        echo "Install Mode:   Stage"
+        echo "STAGE File:     $INSTALL_STAGE"
+    elif [[ "$INSTALL_MODE" == "clean" ]]; then
+        echo "Install Mode:   Clean"
+    else
+        echo "Install Mode:   Normal"
+    fi
+
+	if [[ "$ENCRYPTION" ]]; then
+		echo "Encryption:     Enabled"
+	else
+		echo "Encryption:     Disabled"
+	fi
+
+    if [[ "$COMPRESSION" ]]; then
+		echo "Compression:    Enabled"
+	else
+		echo "Compression:    Disabled"
+	fi
+
+	if [[ "$SWAP" ]]; then
+		echo "Swap:           Enabled"
+	else
+		echo "Swap:           Disabled"
+	fi
+
+	if [[ "$DEBUG" ]]; then
+		echo "Debug:          Enabled"
+	else
+		echo "Debug:          Disabled"
+	fi
+	echo
+}
+
+function install_prep() {
+	show_options
+
+	read -rsn1 -p"Preparation: To proceed, press enter to continue." proceed
+	echo
+	if [[ "$proceed" != "" ]]; then
+		echo "Aborting."
+		exit 1
+	fi
+
+    echo "Creating Partitions on ${RootDisk}..."
+    prepare_disk
+
+	if [[ "$ENCRYPTION" ]]; then
+		echo
+		echo "Initiallizing LUKSv2 on ${RootPart}:"
+		create_luks
+	fi
+
+	echo
+	echo "Formatting Filesystems..."
+	prepare_format
+
+	echo
+	echo "Preparing Subvolumes..."
+	create_subvolumes
+
+	echo
+	echo "Preparing Installation Target..."
+	prepare_target
+
+    echo
+    echo "Installation is ready and mounted in /mnt/gentoo for stage3 or stage4 install"
+    echo "Please verify all went well, and re-run this script with --stage <stagefile>"
+    echo "as appropriate, to continue."
+}
+
+function install_stage() {
+	show_options
+
+	read -rsn1 -p"Stage-Installation: To proceed, press enter to continue." proceed
+	echo
+
+	if [[ "$proceed" != "" ]]; then
+		echo "Aborting."
+		exit 1
+	fi
+
+	echo
+	echo "Running Stage-Mode Installation Steps..."
+    stage_step
+}
+
+function install_cleanup() {
+	show_options
+
+    echo "!!!WARNING!!! This is about to destructively wipe ${RootDisk}!"
+	read -rsn -p"Enter YES to continue." proceed
+	echo
+	if [[ "${proceed,,}" != "yes" ]]; then
+		echo "Aborting."
+		exit 1
+	fi
+
+	if [[ "$DEBUG" ]]; then
+		local cmd="echo"
+	else
+		local cmd=""
+	fi
+
+	for subvol in "${!SUBVOLS_DEFAULT[@]}"
+	do
+		${cmd} umount /mnt/gentoo/"${SUBVOLS_DEFAULT[$subvol]}"
+	done
+
+	${cmd} umount /mnt/gentoo/efi
+	${cmd} umount /mnt/gentoo/boot
+	${cmd} umount /mnt/gentoo/swap
+	${cmd} umount /mnt/gentoo
+
+	if [[ "$ENCRYPTION" ]]; then
+		${cmd} cryptsetup luksClose luksvol
+	fi
+
+    ${cmd} dd if=/dev/zero of="${RootDisk}" bs=1024 count=10
+}
+
+
+declare -a POSITIONAL_ARGS=()
+declare INSTALL_MODE="normal"
+
+while [[ $# -gt 0 ]]; do
+	case $1 in
+		-h|--help)
+			show_help
+			;;
+		-e|--encryption)
+			ENCRYPTION=true
+			shift
+			;;
+        -c|--compression)
+            COMPRESSION=true
+            shift
+            ;;
+		-s|--swap)
+			SWAP=true
+			shift
+			;;
+		-d|--debug)
+			DEBUG=true
+			shift
+			;;
+		--stage)
+			INSTALL_MODE=stage
+            INSTALL_STAGE=$1
+			shift 2
+			;;
+		--clean)
+			INSTALL_MODE=clean
+			shift
+			;;
+		*)
+			POSITIONAL_ARGS+=("$1") # save positional arg
+			shift
+			;;
+	esac
+done
+
+set -- "${POSITIONAL_ARGS[@]}" # restore positional parameters
+
+RootDisk="$1"
+
+if [[ ! -b "$RootDisk" ]]; then
+    echo "ERROR: Invalid parameters. See --help for help"
+    exit 3
+elif
+    if [[ "$ENCRYPTION" ]]; then
+        diskdev="${RootDisk##*/}"
+        if [[ "$diskdev" =~ ^nvme.* ]]; then
+            RootPart="${RootDisk}p3"
+            BootPart="${RootDisk}p2"
+            EFIPart="${RootDisk}p1"
+        else
+            RootPart="${RootDisk}3"
+            BootPart="${RootDisk}2"
+            EFIPart="${RootDisk}1"
+        fi
+    else
+        BootPart="@boot"
+        if [[ "$diskdev" =~ ^nvme.* ]]; then
+            RootPart="${RootDisk}p2"
+            EFIPart="${RootDisk}p1"
+        else
+            RootPart="${RootDisk}2"
+            EFIPart="${RootDisk}1"
+        fi
+    fi
+
+	case "$INSTALL_MODE" in
+		normal) install_prep;;
+		stage)	install_stage;;
+		clean)  install_cleanup;;
+		*)
+			echo "Error, unknown installation mode detected."
+			exit 3
+			;;
+	esac
+fi