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There are some packages that utilise a functionality called streams. Modularity makes it possible to have multiple versions of the same package in the same repository and enables version switching. To be able to build module packages, we are using something called Module Build Service, MBS for short. It is also called fm-orchestrator.

Packages that have modular entries should not be built directly from their dist/ repository as that will not tag that package correctly as a stream.

The correct {name}.yaml file is generated during import with srpmproc and is derived from SOURCES/modulemd.src.txt.

Koji setup

MBS should be able to use content generators so Koji can manage artifacts. To enable content generation run the following queries against the database:

insert into content_generator (name) values ('module-build-service');
insert into btype (name) values ('module');

Grant the mbs user on koji cg-access with:

koji grant-cg-access mbs module-build-service

Also create a tag named modular-updates-candidate with:

koji add-tag modular-updates-candidate

Modular packages should be added to this tag.


Latest MBS version is required. Version 2.32 lacks the mock.yum.module_hotfixes=1 flag on the tags and DNF fail-safe mechanisms break the build.

More info on Modularity here and how we utilise MBS