proxmox-boot: add --next-boot option kernel pin command

by setting the desired version in a dedicated file, which is used
by the systemd service as condition for removing it and refreshing
upon reboot.

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Tested-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

bin/proxmox-boot-tool

@@ -288,11 +288,17 @@ list_kernels() {
 	echo "$boot_kernels"
 
 	pinned_kernel="$(get_first_line "$PINNED_KERNEL_CONF")"
+	nextboot_kernel="$(get_first_line "$NEXT_BOOT_PIN")"
 	if [ -n "$pinned_kernel" ]; then
 		echo ""
 		echo "Pinned kernel:"
 		echo "${pinned_kernel}"
 	fi
+	if [ -n "$nextboot_kernel" ]; then
+		echo ""
+		echo "Kernel pinned on next-boot:"
+		echo "${nextboot_kernel}"
+	fi
 }
 
 usage() {
@@ -303,8 +309,8 @@ usage() {
 	warn "       $0 clean [--dry-run]"
 	warn "       $0 refresh [--hook <name>]"
 	warn "       $0 kernel <add|remove> <kernel-version>"
-	warn "       $0 kernel pin <kernel-version>"
+	warn "       $0 kernel pin <kernel-version> [--next-boot]"
-	warn "       $0 kernel unpin"
+	warn "       $0 kernel unpin [--next-boot]"
 	warn "       $0 kernel list"
 	warn "       $0 status [--quiet]"
 	warn "       $0 help"
@@ -332,14 +338,16 @@ help() {
 	echo "    add/remove pve-kernel with ABI <kernel-version> to list of synced kernels, in addition to automatically selected ones."
 	echo "    NOTE: you need to manually run 'refresh' once you're finished with adding/removing kernels from the list"
 	echo ""
-	echo "USAGE: $0 kernel pin <kernel-version>"
+	echo "USAGE: $0 kernel pin <kernel-version> [--next-boot]"
 	echo ""
 	echo "    pin pve-kernel with ABI <kernel-version> as the default entry to be booted."
+	echo "    with --next-boot sets <kernel-version> only for the next boot."
 	echo "    NOTE: you need to manually run 'refresh' once you're finished with pinning kernels"
 	echo ""
-	echo "USAGE: $0 kernel unpin"
+	echo "USAGE: $0 kernel unpin [--next-boot]"
 	echo ""
-	echo "    unpin sets the latest kernel as the default entry (undoes a previous pin)"
+	echo "    unpin removes pinned and next-boot kernel settings."
+	echo "    with --next-boot only removes the pin for the next boot."
 	echo ""
 	echo "USAGE: $0 kernel list"
 	echo ""
@@ -412,6 +420,7 @@ status() {
 
 pin_kernel() {
 	ver="$1"
+	pin_file="$2"
 
 	if [ -z "$ver" ]; then
 		warn "E: <kernel-version> is mandatory"
@@ -419,17 +428,25 @@ pin_kernel() {
 		exit 1
 	fi
 
+	if [ -z "$pin_file" ]; then
+	    pin_file="$PINNED_KERNEL_CONF"
+	fi
+
 	if [ ! -e "/boot/vmlinuz-$ver" ]; then
 		warn "E: no kernel image found in /boot for '$ver', not setting default."
 		exit 1
 	fi
-	echo "$ver" > "$PINNED_KERNEL_CONF"
+	echo "$ver" > "$pin_file"
-	echo "Set kernel '$ver' $PINNED_KERNEL_CONF. Use the 'refresh' command to update the ESPs."
+	echo "Set kernel '$ver' in $pin_file. Use the 'refresh' command to update the ESPs."
 }
 
 unpin_kernel() {
+	rm -f "$NEXT_BOOT_PIN"
+	echo "Removed $NEXT_BOOT_PIN. Use the 'refresh' command to update the ESPs."
+	if [ -z "$1" ]; then
 		rm -f "$PINNED_KERNEL_CONF"
 		echo "Removed $PINNED_KERNEL_CONF. Use the 'refresh' command to update the ESPs."
+	fi
 }
 
 if [ -z "$1" ]; then
@@ -501,11 +518,25 @@ case "$1" in
 				exit 0
 			;;
 			'pin')
+				if [ "$#" -eq 3 ] && [ "$3" = '--next-boot' ]; then
+					pin_kernel "$2" "${NEXT_BOOT_PIN}"
+				elif [ "$#" -eq 2 ]; then
 					pin_kernel "$2"
+				else
+					usage
+					exit 1
+				fi
 				exit 0
 			;;
 			'unpin')
+				if [ "$#" -eq 2 ] && [ "$2" = '--next-boot' ]; then
 					unpin_kernel "$2"
+				elif [ "$#" -eq 1 ]; then
+					unpin_kernel
+				else
+					usage
+					exit 1
+				fi
 				exit 0
 			;;
 			*)

debian/pve-kernel-helper.install

@@ -2,6 +2,7 @@ etc/grub.d/000_proxmox_boot_header
 etc/kernel/postinst.d/*
 etc/kernel/postrm.d/*
 etc/initramfs/post-update.d/proxmox-boot-sync
+lib/systemd/system/proxmox-boot-cleanup.service
 usr/sbin/proxmox-boot-tool
 usr/sbin/grub-install
 usr/share/pve-kernel-helper/scripts/functions

debian/rules

@@ -12,5 +12,8 @@ debian/control: $(wildcard debian/*.in)
 %:
 	dh $@
 
+override_dh_installsystemd:
+	dh_installsystemd --no-start
+
 .PHONY: build clean
 build clean:

proxmox-boot/Makefile

@@ -2,12 +2,14 @@ KERNEL_HOOKSCRIPTS = proxmox-auto-removal zz-proxmox-boot
 INITRAMFS_HOOKSCRIPTS = proxmox-boot-sync
 SHARE_FILES = functions
 GRUB_CFG_SNIPPET = 000_proxmox_boot_header
+SYSTEMD_SERVICES = proxmox-boot-cleanup.service
 
 POSTINSTHOOKDIR = ${DESTDIR}/etc/kernel/postinst.d
 POSTRMHOOKDIR = ${DESTDIR}/etc/kernel/postrm.d
 POSTINITRAMFSHOOKDIR = ${DESTDIR}/etc/initramfs/post-update.d
 SHARE_SCRIPTDIR = ${DESTDIR}/usr/share/pve-kernel-helper/scripts
 GRUB_CFG_DIR = ${DESTDIR}/etc/grub.d
+SERVICE_DIR = ${DESTDIR}/lib/systemd/system
 
 .PHONY: all
 all:
@@ -23,6 +25,8 @@ install:
 	install -m 0755 ${SHARE_FILES} ${SHARE_SCRIPTDIR}
 	install -d ${GRUB_CFG_DIR}
 	install -m 0755 ${GRUB_CFG_SNIPPET} ${GRUB_CFG_DIR}
+	install -d ${SERVICE_DIR}
+	install -m 0644 ${SYSTEMD_SERVICES} ${SERVICE_DIR}
 
 .PHONY: clean distclean
 distclean:

proxmox-boot/functions

@@ -6,6 +6,7 @@ ESPTYPE='c12a7328-f81f-11d2-ba4b-00a0c93ec93b'
 
 MANUAL_KERNEL_LIST="/etc/kernel/pve-efiboot-manual-kernels"
 PINNED_KERNEL_CONF="/etc/kernel/proxmox-boot-pin"
+NEXT_BOOT_PIN="/etc/kernel/next-boot-pin"
 
 MOUNTROOT="${TMPDIR:-/var/tmp}/espmounts"
 # relative to the ESP mountpoint
@@ -60,6 +61,7 @@ kernel_keep_versions() {
 	fi
 
 	pinned_kernel="$(get_first_line "$PINNED_KERNEL_CONF")"
+	nextboot_kernel="$(get_first_line "$NEXT_BOOT_PIN")"
 
 	kernels="$(cat <<-EOF
 		$running_version
@@ -69,6 +71,7 @@ kernel_keep_versions() {
 		$series_metapackages
 		$oldseries_latest_kernel
 		$pinned_kernel
+		$nextboot_kernel
 		EOF
 	)"
 

proxmox-boot/proxmox-boot-cleanup.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=Clean up bootloader next-boot setting
+After=systemd-remount-fs.service
+ConditionPathExists=/etc/kernel/next-boot-pin
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=/usr/sbin/proxmox-boot-tool kernel unpin --next-boot
+ExecStart=/usr/sbin/proxmox-boot-tool refresh
+
+[Install]
+WantedBy=multi-user.target

proxmox-boot/zz-proxmox-boot

@@ -93,6 +93,9 @@ update_esp_func() {
 
 	pinned_kernel=$(get_first_line "${PINNED_KERNEL_CONF}")
 
+	if [ -e "${NEXT_BOOT_PIN}" ]; then
+	    pinned_kernel=$(get_first_line "${NEXT_BOOT_PIN}")
+	fi
 	if [ -d /sys/firmware/efi ]; then
 		set_systemd_boot_default "${mountpoint}" "${pinned_kernel}"
 		remove_old_kernels_efi "${mountpoint}"