Krita snap cannot access a mounted HDD

snap
1

I installed Krita successfully on Ubuntu 22.04 I have a second HDD auto mounted (fstab) at /PHOTOS but krita cannot see it.

When I install Krita with apt the hard drive is visible normally.

I’ve read that this is a security measure, but if so it would be nice if there was a way of circumventing it.

2

If I’m not mistaken, a Snap app that has the removable-media plug can access HDDs mounted in /media, run/media, and /mnt.

I installed Krita and it has this plug; it even connects automatically.

3

Thanks… but I’m not talking about removable media. This is an installed second drive with a permanent fstab entry.

4

“removable-media” is just a name; it doesn’t mean it’s only for USB flash drives, for example.

5

(post deleted by author)

6

A bind-mount to an accessible place (e.g. in /media, /run/media, or /mnt with removable-media; or your home directory…) should work as a workaround.

Also note according to its assert file, that the krita snap has automatic r/w access to $HOME/\.local/share/krita, so that may be also worth considering to bind-mount. But I cant find that when looking into its snapcraft.yaml file, so maybe that does not work. (Yikes, i had to snap download and unsquashfs to figure all that out; isnt there UI for seeing permissions without installing a snap(?)). According to the snapcraft yaml it supports the home and removable-media connections; if that is not auto-connected you could add those connection manually.

Rechecking the assert file, ~/.local/share/krita and removable-media are auto-connected, so in your shoes I would mount (or adding a bind-mount) at /mnt/PHOTOS. That does not give extra permissions to the snap and seems okayish.

On the other hand I am bit surprised, I would expect krita to use the file picker portal (where you should be able to any path AFAIK); isnt that so or is it not working with your hdd or is that simply not enough for your use case?

7

I’ve used an unconventional mount point for the HDD, namely /PHOTOS

I can’t think of any unix reason not to do this and I have lots of mini scripts etc for my setup, which I would have to change.

Can someone tell me where to look … I’ve looked at the Krita snapcraft.yaml and all I can find is

 plugs:
  - home
  - removable-media
  - cups

If this is the right place to look, can I specify the whole filesystem, and if so, how? Where would I find the documentation for all the options? I’ve looked at the docs for snapcraft.yaml but there doesn’t seem to be a list of options apart from home and removable-media. It’s a bit opaque.

Any help appreciated… thanks.

8

I can’t think of any unix reason not to do this and I have lots of mini scripts etc for my setup, which I would have to change.

Just remember this is not “unix” territory, this is “nested operating systems in your host system” or “installing applications from external ecosystems”. So there are valid reasons which are not directly applicable to “normal” unix.

There is no direct support for arbitrary host paths in the snap ecosystem. If you want to see official documentation for a similar case: Home directories outside of '/home' | Snapcraft documentation

What you should not do: It may be possible to circumvent the container/sandbox and there is a chance krita works on your system without any safety or other guarantees.

What you should do - if you want to use the krita snap and keep the data in the /PHOTOS location, use a bind mount so the snap can find it.

It should work like this (if you use /mnt as base);

$ sudo mkdir -p /mnt/PHOTOS
$ sudo mount --bind /PHOTOS /mnt/PHOTOS