Is there a specification for the YUM metadata?

Question

I'm trying to find a trusted point of truth for the following yum metadata files:

• primary.xml.gz
• filelists.xml.gz
• other.xml.gz
• repomd.gz
• groups.xml.gz

I've been looking around the Internet, but I haven't found a definitive reference, or guide. Is there a concrete specification, or RFC for this, or is this open for interpretation and implementation?

I've come across these useful links:

• Anatomy of YUM Repositories: A Look Under The Hood
• YUM Repository And Package Management: Complete Tutorial
• openSUSE: Standards RPM Metadata

But I haven't managed to find an actual specification for this. Does anybody know if there is one, or where to find more details?

Cyclosis

Well, the wiki for the project that defines the format has the line: "FIXME The specification needs better and more current documentation and needs to be included here." So that doesn't bode well, haha.. – Vague

I know! :) And I can see that the different Linux distributions have implemented their own interpretations of how it should work. We would like to implement a layout provider for YUM in our artifact repository manager (called Strongbox: github.com/strongbox/strongbox/issues/845). We are trying to gather the requirements of how to properly implement YUM metadata support (here: github.com/strongbox/strongbox/issues/993). This is why we're looking for a more definitive source of truth. We were hoping for an RFC of some sort... Any help would be welcome! :) – Cyclosis

Time to dig into the source for createrepo... – Arsenious

Ask the YUM mailinggroup : yum.baseurl.org – Dittman