Stage 4: Calamares installer and Btrfs snapshots (0.2.0)

- Package Calamares 3.4.3 (Qt6, widgets UI) with xbps-src. - das-installer: Calamares setup for Void/runit with Das OS branding and slides. It copies the clean live image (live-base), builds locales and the host-only initramfs, rewrites kernels without sparse tails (GRUB 2.12 cannot read Btrfs holes at the end of a file), then removes itself. - das-snapshots: flat Btrfs layout (@, @home, @snapshots, @var_log, @var_cache_xbps), snapper with hourly snapshots via cronie, grub-btrfs menu, snapper-rollback, and a dracut module that boots read-only snapshots with a RAM overlay. - das-settings 0.2.0: start LightDM with the system locale. - Live image: GRUB, efibootmgr and the new packages; Das OS /etc/issue. - Build: wipe stale destdirs before building packages. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-19 08:59:09 +03:00
parent b7399031c7
commit ecced4e3f4
51 changed files with 849 additions and 14 deletions
@@ -0,0 +1 @@
+../../../LICENSE
@@ -0,0 +1,49 @@
+#!/bin/sh
+# Set up snapper for a Das OS root file system on Btrfs.
+#
+# Expects the layout created by the installer: the root in subvolume @ and
+# snapshots in subvolume @snapshots mounted at /.snapshots, which is what
+# snapper-rollback needs. Safe to run again.
+set -eu
+
+msg() { echo "das-snapper-setup: $*"; }
+
+if [ "$(id -u)" -ne 0 ]; then
+	msg "must be run as root" >&2
+	exit 1
+fi
+if [ "$(findmnt -no FSTYPE /)" != btrfs ]; then
+	msg "the root file system is not Btrfs, nothing to do"
+	exit 0
+fi
+if [ "$(findmnt -no FSTYPE /.snapshots 2>/dev/null)" != btrfs ]; then
+	msg "/.snapshots is not a mounted Btrfs subvolume" >&2
+	exit 1
+fi
+
+if [ ! -e /etc/snapper/configs/root ]; then
+	install -m 640 /usr/share/das/snapper/root /etc/snapper/configs/root
+	msg "created /etc/snapper/configs/root"
+fi
+if ! grep -q '^SNAPPER_CONFIGS=".*\broot\b' /etc/conf.d/snapper; then
+	sed -i 's/^SNAPPER_CONFIGS=.*/SNAPPER_CONFIGS="root"/' /etc/conf.d/snapper
+fi
+chmod 750 /.snapshots
+chgrp wheel /.snapshots
+
+# snapper-rollback mounts the top-level subvolume from this device.
+dev=$(findmnt -no SOURCE / | sed 's/\[.*\]$//')
+uuid=$(blkid -s UUID -o value "$dev")
+sed -i "s|^#\?\s*dev = .*|dev = /dev/disk/by-uuid/$uuid|" /etc/snapper-rollback.conf
+
+# Name the GRUB submenu that grub-btrfs adds
+cfg=/etc/default/grub-btrfs/config
+if [ -f "$cfg" ] && ! grep -q '^GRUB_BTRFS_SUBMENUNAME=' "$cfg"; then
+	echo 'GRUB_BTRFS_SUBMENUNAME="Das OS snapshots"' >>"$cfg"
+fi
+
+# Hourly snapshots come from cron, and grub-btrfs adds them to the boot menu.
+for sv in cronie grub-btrfs; do
+	ln -sfn "/etc/sv/$sv" "/etc/runit/runsvdir/default/$sv"
+done
+msg "snapshots are enabled"
@@ -0,0 +1,2 @@
+# Lets a read-only snapper snapshot boot from the GRUB menu (see das-snapshot-overlay).
+add_dracutmodules+=" das-snapshot-overlay "
@@ -0,0 +1,14 @@
+#!/bin/sh
+# Snapper snapshots are read-only, and the system can't start from a read-only
+# root. When GRUB boots a snapshot, mount it under an overlay whose writable
+# layer lives in RAM. Changes made in that session are lost at shutdown.
+
+[ "$(btrfs property get -ts "$NEWROOT" ro 2>/dev/null)" = "ro=true" ] || return 0
+
+info "das-snapshot-overlay: read-only snapshot, adding a writable overlay"
+lower=$(mktemp -d -p /)
+ram=$(mktemp -d -p /)
+mount --move "$NEWROOT" "$lower"
+mount -t tmpfs -o mode=0755 das-overlay "$ram"
+mkdir -p "$ram/upper" "$ram/work"
+mount -t overlay -o "lowerdir=$lower,upperdir=$ram/upper,workdir=$ram/work" das-overlay "$NEWROOT"
@@ -0,0 +1,20 @@
+#!/bin/bash
+# Dracut module: boot read-only Btrfs snapshots with a writable overlay in RAM.
+
+check() {
+	require_binaries btrfs || return 1
+	return 0
+}
+
+depends() {
+	echo btrfs
+}
+
+installkernel() {
+	hostonly='' instmods overlay
+}
+
+install() {
+	inst_multiple btrfs mktemp
+	inst_hook pre-pivot 10 "$moddir/das-snapshot-overlay.sh"
+}
@@ -0,0 +1,37 @@
+# Snapper configuration for the Das OS root file system.
+# das-snapper-setup copies it to /etc/snapper/configs/root.
+
+SUBVOLUME="/"
+FSTYPE="btrfs"
+QGROUP=""
+
+# Snapshots may use at most half of the file system and must leave 20% free.
+SPACE_LIMIT="0.5"
+FREE_LIMIT="0.2"
+
+# Members of wheel can list and compare snapshots without sudo.
+ALLOW_USERS=""
+ALLOW_GROUPS="wheel"
+SYNC_ACL="yes"
+
+BACKGROUND_COMPARISON="yes"
+
+# Snapshots made by das-update and by hand.
+NUMBER_CLEANUP="yes"
+NUMBER_MIN_AGE="3600"
+NUMBER_LIMIT="20"
+NUMBER_LIMIT_IMPORTANT="10"
+
+# Hourly snapshots made by cron.
+TIMELINE_CREATE="yes"
+TIMELINE_CLEANUP="yes"
+TIMELINE_MIN_AGE="3600"
+TIMELINE_LIMIT_HOURLY="5"
+TIMELINE_LIMIT_DAILY="7"
+TIMELINE_LIMIT_WEEKLY="2"
+TIMELINE_LIMIT_MONTHLY="0"
+TIMELINE_LIMIT_QUARTERLY="0"
+TIMELINE_LIMIT_YEARLY="0"
+
+EMPTY_PRE_POST_CLEANUP="yes"
+EMPTY_PRE_POST_MIN_AGE="3600"