[AppStream] Metadata repository

[Laura Morales]

So, if I understand correctly, I should be able to create my own archive by downloading all the "collection metadata" from various distributions? Right?
And if I download all this data, can I use it to draw package statistics across distributions? For example like "software-1 is available on Debian Stretch and Fedora 28, but not Arch"?

 
 

Sent: Tuesday, April 10, 2018 at 4:27 AM
From: "Matthias Klumpp" <matthias at tenstral.net>
To: "Laura Morales" <lauretas at mail.com>
Cc: appstream at lists.freedesktop.org
Subject: Re: [AppStream] Metadata repository
2018-04-06 12:46 GMT+02:00 Laura Morales <lauretas at mail.com>:
> I've just learned about AppStream, if I understand correctly it's a way to standardize packages metadata across distributions.

Saying "package metadata" is very misleading. The metadata is
"component metadata" which describes software components. There is
some overlap with "package" metadata, but it is not the same.
The AppStream metadata is commonly supplied by upstream projects and
then only transformed slightly by the Linux distribution for
consumption by software centers.

I think I answered a related question recently already:
https://github.com/ximion/appstream/issues/176


> Is there already a public, downloadable repository of such metadata?

It is important to note that there are two types of "AppStream
metadata": Metainfo files, that are supplied by upstream projects
directly, and Collection metadata, that is usually assembled by
distributors and contains a collection of the metainfo data in a
slightly different format.

While the metainfo data exists only in XML, the collection data can
exist in YAML or XML.
See https://appstream.debian.org/data/sid/main/[https://appstream.debian.org/data/sid/main/] for Debian's
collection data for example, or
https://apps.fedoraproject.org/packages/appstream-data/[https://apps.fedoraproject.org/packages/appstream-data/] for a Fedora
package with their data.