Seeing any snap via snap_preseed will evaluate the base for each snap
and seed the appropriate base. There should be no reason to explicitly
seed the 'core' snap and with snaps moving to 'core18' this will add
'core' without need.
The _snap_post_process function is meant to install snapd if core18 is the
only core snap installed or removed snapd if core is installed and snapd
was not explicitly installed. But the current logic in _snap_preseed
will never call _snap_post_process. $core_name will never be empty
with the existing logic, but even if it were that would only be for the
'core' snap and we'd miss using the 'core18' logic that pulls in snapd.
Given the case statement in _snap_post_process can handle doing the
right thing given any snap we can just call it unconditionally.
Back in 2017 some code was added to ignore failures tearing down loop
devices. But debugging that growpart race on cloud images made me (very)
aware of a potential cause of the race: doing something like zerofree on
a device will cause udev scripts to run, and if they are still running
by the time kpartx is called, you would expect the kpartx -d to fail. So
lets see if a udevadm settle helps, and get rid of one of the "sometimes
this fails but we don't know why" comments...
With the removal of snap-tool failures are seen in image builds that do
not have the 'core' snap included by the seed. This is the case for the
minimized subproject of the ubuntu-cpc project where lxd/core is removed.
In that subproject, any binary hook which adds a snap that is based
on 'core' will not add 'core' and fail 'snap debug validate-seed'.
snap-tool included the following logic in the 'snap-tool info' when
determining snap bases:
# Have "base" initialized to something meaningful.
if self.is_core_snap():
snap_data["snap"]["base"] = ""
elif snap_data["snap"].get("base") is None:
snap_data["snap"]["base"] = "core"
The snap store does not return a base if the base is core which makes
this necessary. This patch looks for the base in 'snap info' output
and if none is found (and the snap is not snapd or core) it assumes the
base is 'core' and installs it. This restores the behavior lost in the
migration from snap-tool to snap cli.
snap-tool was added to support a deprecate cohort-key feature of the snap store.
Recent changes in snap assertions have added additional fields which snap-tool
is not retrieving. This resulted in snap install failures on first boot.
This patch removes snap-tool and returns to using the snap cli. This ensures
snap downloads will function without odd incompatibilities.
When getting the list of snaps to include on an image via germinate, we
process the snaps in alphabetical order. Currently we seed several
packages `gnome-foo` and also `gtk-common-themes`, the default provider
of `gtk-3-themes`. Since `gtk-common-themes` is alphabetically after
`gnome-foo`, the `seed.yaml` we generate is invalid when we are part way
through generating.
What we really care about, though, is not that the `seed.yaml` is always
valid at every step, but it is that it is valid at the *end* of seeding.
So for the germinate case, let's defer validation to happen once at the
end. Other callsites of `snap_preseed`, where callers are careful to
seed snaps in the right order, are unaffected by this.
This is apparently still required; without it snapd gives an error
message like:
stateengine.go:102: state ensure error: devicemgr: cannot proceed without seeding "core"
Util-linux 2.33 fixed mount --rbind --make-rslave which did not pass MS_REC
with MS_BIND and livecd-rootfs did only --bind --make-rslave effectively with
prior mount versions.
While mount --rbind --rslave are properly passed the flags to mount()
unmounting did not work cleanly with --make-rslave.
To clearly stop propagation of umount, --make-private is used instead of
--make-rslave and it is always set before umounts. Umount -R is replaced
with a simple umount since submounts are tore down in teardown_mountpoint()
earlier.
LP: #1813730
