The Jenkins debian-glue jobs are used to magically create Debian packages out of Gerrit a patchset thanks to the [[ http://jenkins-debian-glue.org/ | jenkins-debian-glue ]] scripts. They magically create cow images for the targetted distribution but are missing the apt.wikimedia.org configuration.
@akosiaris provided a puppet class ( https://gerrit.wikimedia.org/r/#/c/194471/ ) which creates cow images for all distributions we care about. That let us switch easily between them by simply setting the DIST env variable. Thus, we can have all debian-glue jobs to be solely on Jessie instances.
The new puppet role is [[ https://gerrit.wikimedia.org/r/#/c/200525/ | role::package::builder ]]. It is to be applied on Jessie CI slaves, we have to make sure the extended disk space is mounted under /mnt and pbuilder default dir pointed to it.