Package createrepo

Creates a common metadata repository

http://createrepo.baseurl.org/

This utility will generate a common metadata repository from a directory of rpm
packages.

General Commands (Section 1)
mergerepo
mergerepo is a program that allows you merge multiple repositories into a single repository while referring to the remote location for all packages.
modifyrepo
modifyrepo is a program that allows you to insert arbitrary metadata into a repomd (xml-based rpm metadata) repository.
System Administration (Section 8)
createrepo
createrepo is a program that creates a repomd (xml-based rpm metadata) repository from a set of rpms.