"Snap" question

[Oliver Grawert]

hi,
Am Donnerstag, den 10.12.2020, 18:13 -0500 schrieb Robert Heller:
> I just installed xv under snap using the instructions here:
> 
> https://snapcraft.io/install/xv/ubuntu
> 
> And I am encountering a "weirdness" (at least to me).  I can only
> access and 
> view images that are under $HOME.  Images located elsewhere yield a
> file not 
> found error (the files are in fact there and I was able to view them
> with xv 
> installed under CentOS 6 (from a standard RPM).

this is pretty normal behavior for confined snaps, they access the
outside world of their confinement vi interfaces, typically desktop
apps have the home interface auto-connected (as you found) that enables
you to access all iles in ~/ with the exception of any hidden dirs (so
we can guarantee that a snapped app can not access any information of
any other app unless you allow it to explicitly)

often apps also have the removable-media interface available, that
allows access to /mnt and /media ... so the easiest to give apps access
to your additional disks would be to mount them there ... 

one part of file access confinement is managed by the kernels apparmor
security mechanism, apparmor does not allow you to follow links t
outside areas of teh defined confinement *but* it allows access to
mounts, so another option to gain access to your disks is to simply set
up a bind mount between their mount points and an accessible place
(/home/mydisk-foo ... /media/mydisk-bar ... )


> Is there some "magic" to allow xv to view files anywhere on any file
> system 
> (permissions permitting)?

all that above said, the xv snap is clearly only available in the edge
channel *and* only installable by defining --devmode ...

the first one here tells you that this snap is not really done yet,
typically things in edge are under development, untested, buggy etc 

second, if you install it with the --devmode option (as installing it
from comandline will suggest to you) you turn off all confinement and
as such, you should be able to access any place on the filesystem.

did you use --jailmode instead of -devmode when installing it ?

ciao
	oli
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