Re: What exactly is Snap or Flatpack ?

On 10/19/2024 15:55, Rich wrote:

Lars Poulsen <lars@cleo.beagle-ears.com> wrote:

I feel like I have been living under a rock for the the last decade
whenever people mention /snap/ and /flatpack/.
>
1) Are they the same idea as /kubernetes/, and if not, then what is
    *that*?

 In a /similar/ ballpark, but not quite /the same/:
 Snap: https://en.wikipedia.org/wiki/Snap_(software)
 Flatpak: https://en.wikipedia.org/wiki/Flatpak
 

2) What is the difference between them (other than that they are two
    incompatible brands, like /apt/ and /yum/ (aka /dnf/) are functionally
    the same thing, but incompatible with each other)?

 They are very similar to each other, to the point that one looks to be
a NIH syndrome [1] of the other.
 

Is it just packaging the executable with all the libraries it references
and a wrapper that sets up paths to those libraries, or is there a
virtual machine involved?

 Both run inside a "sandbox".  So they therefore depend upon whether
your definition of "virtual machine" extends to include "sandboxed"
software.
 

Do these wrapped applications see the full file system, or is there a
shell game of /chroot/ and links or loopback mounts to break out?

 Presumably they have a limited view of the native filesystem.  The snap
wikipedia page says "limited access to the host system" but does not
define if the "limits" included "limited access to native filesystem".
The Flatpak wikipedia page says "Flatpak[s] need permission to access
... files" so it somewhat more explicitly implies a limited view of the
native filesystem.
 

At 74 I am old, but I hope to still learn some new things!

 [1] Not Invented Here
  

Just to add to what has already been said, snap and flatpak packages tend to include all their dependencies so it is a self-contained packages that doesn't tend to need dependencies beyond the package manager itself. If I recall (I don't use flatpaks) they are mostly statically linked within the pack so regardless of which distribution or GNU/Linux installation you use, it's compatible (within reason). Based on the technical definition of a virtual machine (a self-contained hypervisor that is isolated from the rest of the hardware within the CPU and memory mapping) it is not a VM. And I don't consider it a container either (although others will likely disagree). it's just a package that contains everything the application needs to run. And since it's kept in a nice package, it's easy to remove as well.
--
Phillip Frabott
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