[yocto] Disabling sshd is harder than it should be

[Loïc Domaigné]

Guten Abend Richard, 

> > When selecting systemd as the init manager, the following line is
> > recommended.
> > DISTRO_FEATURES_BACKFILL_CONSIDERED += "sysvinit"
> > Then you should only need: SYSTEMD_AUTO_ENABLE = "disable"
> 
> Thanks a lot for your suggestion!
> But doesn't this line imply that recipes which don't supply systemd servies
> files won't work since the init.d scipt fallback will be disabled?

As per Mega-manual (section "using systemd Exclusively"):
# switch to systemd init
DISTRO_FEATURES_append = " systemd"
VIRTUAL-RUNTIME_init_manager = "systemd" 

# The next 2 lines:
# -prevent sysvinit of being automatically added to the image (BACKFILL_CONSIDERED), 
# -remove the initscripts from the image (VIRTUAL-RUNTIME_initscripts) 
DISTRO_FEATURES_BACKFILL_CONSIDERED = "sysvinit"
VIRTUAL-RUNTIME_initscripts = ""

Now "pokying around" further in meta/ and meta-poky/, it turns out that that later variable might be what you're looking for. 

As far as I can see, it can be set to:
VIRTUAL-RUNTIME_initscripts = ""
VIRTUAL-RUNTIME_initscripts = "initscripts"
VIRTUAL-RUNTIME_initscripts = "systemd-compat-units"

Also using "+=" operator for BACKFILL_CONSIDERED as suggested by Qi sounds more generic to me than using a plain assignment.

Speaking of which... Additional findings (meta/conf/distro/include/maintainers.inc) let me also think that Qi is simply just the right address for these kind of questions ;-) 

Ah, and yes. If you are moving from sysvinit -> systemd for an existing project, you might need a clean build as DISTRO_FEATURES is changed.

Hope this helps!
Loic.