[PATCH v2] base-files: restore status of system-services after sysupgrade

[Sven Roederer]

Am Dienstag, 12. Januar 2021, 19:56:54 CET schrieb Hannu Nyman:
> Martin Schiller kirjoitti 12.1.2021 klo 9.25:
> > On 2021-01-11 23:07, Sven Roederer wrote:
> >> Restore the status of the system-services after sysupgrade.
> >> Create a file with the status of all known services and keep it during
> >> upgrade. After upgrade run a uci-default script to restore every
> >> single service.
> > 
> > Doing the restore in an uci-default script is to late, because then you
> > are already in the procd rcS helper "loop" and new added init links
> > won't get called.
> > 
> > Also, have you thought about a backup/restore of the configuration?
> > The whole thing should/must work there as well.
> > 
> > I would do the restore at the end of the pre-init stage.
> > 
> > Martin
> 
> My two cents to the discussion:
> 
> * I assume that a small minority of users actually disable services, or at
> least disable several services, so defaulting to "lets by default always
> store status of all services" sounds like overkill.
> 
> * Backuping always info that the dozens of standard services are enabled
> sounds unncessary. As services are installed by default as "enabled" to the
> image, it might make sense to store only info about "disabled" services and
> disable those when restoring the backup in sysupgrade.  (Re-enabling the
> already enabled services is unnecessary.)  That would also help to keep the
> amount of new backup info small.
> 
> * make clear in sysupgrade script help texts and documentation that
> saving/restoring service status depends on "keep settings". If settings are
> not kept, the service status can not be copied in sysupugrade as there is no
> sysupgrade.tar.gz to be passed. (And naturally it would not even make sense
> to e.g. revert network settings to defaults but keep selected network
> services disabled. Easy to cause soft-bricks that way.)
> 
> 
Hannu,

as long as no service was disabled with the "DISABLED_SERVICES" option of the 
imagebuilder the explicit "enable" is not required.
Indeed enabling a service that have been disabled during image creation is a 
bit edge-case, but I prefer here the "full featured" way. Not enabling such a 
service also breaks the user experience like the disable case.

For sure I can add a explicit note, that the "-n" option will not keep the 
states. But "do not save configuration over reflash" imho implicitly means all 
image defaults are used.