When I install a snap with snap install <SNAPNAME> then it is being downloaded and mounted. When I remove it with snap remove <SNAPNAME> then 'everything' is being deleted like the snap, user settings dependecies and so on. But when I re-install the snap after removing it, it has no download time so the snap must be stored somewhere.
How can I clear the cache of snapd with all uninstalled snaps?
When I type:
$ mount|grep snap
/var/lib/snapd/snaps/ubuntu-core_352.snap on /snap/ubuntu-core/352 type squashfs (ro,relatime)
/var/lib/snapd/snaps/ubuntu-core_423.snap on /snap/ubuntu-core/423 type squashfs (ro,relatime)
/var/lib/snapd/snaps/ubuntu-core_122.snap on /snap/ubuntu-core/122 type squashfs (ro,relatime)
I see several old snap "mounted" and available while only the latest version is used as current in /snap/ubuntu-core
It's not a big deal but do I need older ubuntu core ? Isn't this a bug there are not deleted ? Could I simply unmount and delete the files ?
In recent c't (sadly paywalled) there is an article about Snap and Flatpak.
This sounds very similar to Docker, lots of concepts are the same. Now my question what's the difference between Snap and Docker? Are those different use cases?
I know that I can update a snap package using
sudo snap refresh <package>
But is there a way to update all snaps, like
sudo apt dist-upgrade
Before everyone rushes to mark this as a duplicate, I have indeed read the other threads here and here, googled this, and visited the snappy homepage here searching to clear my confusion, and I couldn't. I ask here because I still remain confused. I understand that it is some sort of a minimal working ubuntu, and the spirit of this question is not what is "in it", rather what it is and how it works.
What is the snappy approach to applications? The homepage describes some of it's merits, but as a user, how will I get the apps? Do I still sudo apt-get install XXXX? Or something else?
Will regular ubuntu applications work if I install snappy (the same thing that works on my normal ubuntu install using apt-get or by downloading a deb package), or does someone need to do something special to make an app work in snappy?
Snappy Core is available for Raspberry Pi, for instance, which is a different (mobile) processor, if I install snappy on that, will regular desktop apps still work on Pi? Is that the point of snappy?
If the standard approach does not work, how do I get applications, where do I search for what applications are available for snappy, and how do I install them.
Thank you. My questions are formulated to the best of my understanding of how applications work and are installed in Ubuntu, but please edit them to make more sensible if you get what I mean to ask.