App access to SD card

[Borim]

Currently there is no possibility for applications to ask for permission to access the SD card for application specific data. Bug #1391930 solved the issue for pictures and videos.
In my eyes the usefulness of the SD card is strongly reduced, as app data can not be moved to external memory.

If you develop a app which need a lot of data you have currently only the possibility to miss use the picture/video access rights for the SD card or to bypass the predefined policy groups.
Both solutions goes in the wrong direction.

An example is OSMScout (https://github.com/fransschreuder/OSMScout-ubuntu) the offline navi app for Ubuntu. The maps are way too big for the internal memory (I own a bq E4.5).
I choose to compile OSMScout myself with the tweaked apparmor profile used in the open store version.

I am sure this is not the only app which is affected by the missing permission issue.

Currently the app specific data is stored under $(HOME)/.local/share/$(APP_ID). Why not apply a similar folder structure on the SD card?

[Jamie Strandboge (jdstrand)]

Thank you for reporting a bug. This isn't a missing permission but instead intentionally left out of the policy because we can't depend on the SD card's filesystem to properly handle long filenames. But beyond that, the platform does not currently support external storage in a way that apps can easily consume. This is being worked on and has been discussed at length several times on the ubuntu-phone@ mailing list. The latest thread is here:
https://lists.launchpad.net/ubuntu-phone/msg13432.html

I'm going to change this away from apparmor-easyprof-ubuntu to content-hub, since that is where the work is expected to happen.