[pve-devel] [PATCH pve-kernel-meta 0/5] proxmox-boot: add kernel pinning functionality (#3761)

[Stoiko Ivanov]

The following series adds:
* proxmox-boot-tool kernel pin <kabi-version> (to permanently set the
  default entry of the respective bootloader)
* proxmox-boot-tool kernel unpin (to undo a previous pin)
* proxmox-boot-tool kernel next-boot (to do a pin+touch a file, which causes
  an unpin on next boot)

This is the first functionality which is available for 'regular grub-setups'
(i.e. systems setup with lvm-thin with our ISO or systems installed on top
of plain debian) as well.

The first two patches are cleanup+refactoring (and should not change any
functionality)

The choices (those I think might benefit from a bit of feedback) for this
implementation were:
* for grub - automaticially rewrite '/etc/default/grub' (as this is where
  I'd look to check whether some default is set)
* for systemd - set the entry in the loader.conf and not in the efivars
  (`bootctl set-default/set-once`) - mostly from my bias towards config
  files instead of UEFI vars (depending on implementation quality of the
  UEFI) - another reason was to keep the implementation close for both
  boot-loaders
* for p-b-t booted systems the need to run `p-b-t refresh` manually
  afterwards (following the behavior of `p-b-t kernel add/remove`) could
  be changed to invoking the refresh directly (as with non-p-b-t booted
  systems). Especially since it might make sense to 'add' multiple kernels
  and then do the mount+copy+configupdate only once, whereas you can only
  pin on version anyways

Tested on three VMs installed from the 7.1 ISO (UEFI+ZFS, legacy+ZFS,
UEFI+lvm-thin).

Stoiko Ivanov (5):
  proxmox-boot: drop unused potential_esps function
  proxmox-boot: add get_first_line_from_file helper and use it
  proxmox-boot: fix #3671 add pin/unpin for kernel-version
  proxmox-boot: add kernel next-boot command
  proxmox-boot: add pin/unpin functionality for non-p-b-t systems

 bin/proxmox-boot-tool                     | 65 +++++++++++++++++++++--
 debian/pve-kernel-helper.install          |  1 +
 debian/rules                              |  3 ++
 proxmox-boot/Makefile                     |  4 ++
 proxmox-boot/functions                    | 46 ++++++++++++++++
 proxmox-boot/proxmox-boot-cleanup.service | 15 ++++++
 proxmox-boot/zz-proxmox-boot              | 15 +++---
 7 files changed, 137 insertions(+), 12 deletions(-)
 create mode 100644 proxmox-boot/proxmox-boot-cleanup.service

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2.30.2