[PATCH RFC] base-files: sysupgrade: always setup overlay when creating backup

[Eric]

On Tuesday, February 13th, 2024 at 13:31, Rafał Miłecki <zajec5 at gmail.com> wrote:
> From: Rafał Miłecki rafal at milecki.pl
> 
> Setting overlay while creating backup allows including extra files in
> archive without actually writing them to flash. Right now this feature
> is limited to /etc/backup/ directory and is used only for including
> installed_packages.txt.
> 
> Extend this solution to make it more generic:
> 1. Always mount overlay while creating backup
> 2. Overlay whole / to don't limit it to /etc/backup/
> 
> This allows including any additional files in backups and adding more
> sysupgrade features.
... 
> ---
> This will allow me to include /etc/uci-defaults/ scripts in backups so
> we can e.g. have script disabling previously disabled services.

There is a pending PR[1] against the auc package that looks for
    /rom/etc/uci-defaults/99-asu-defaults
and if found sends its contents in a request to the ASU build server
for inclusion in uci-defaults.  Am I correct in assuming that this
proposal would allow an alternative mechanism for accomplishing the
same thing, thus making the PR (and, in fact, the 'defaults' mechanism
of the ASU build server) redundant?

Also, what are the implications for uci-defaults on ext4?  Do we need
something that creates a first-boot-backup for sysupgrade to use later?

[1] - https://github.com/openwrt/packages/pull/22144

Eric