[JIRA] (OVIRT-2165) Use the Overlayfs mock plugin

Barak Korren created OVIRT-2165: ----------------------------------- Summary: Use the Overlayfs mock plugin Key: OVIRT-2165 URL: https://ovirt-jira.atlassian.net/browse/OVIRT-2165 Project: oVirt - virtualization made easy Issue Type: Epic Components: mock_runner Reporter: Barak Korren Assignee: infra mock has a plugin that allows it to store chroots on overlayfs instead of the normal FS: Details about the plugin can be found here: https://github.com/rpm-software-management/mock/wiki/Plugin-Overlayfs The plugin allows to quickly restore a chroot from a snapshot - this can at the very least make the CI faster by 20 seconds, by saving time spent on extracting the tarball from the chroot cache. the plugin also adds a full snapshot and restore mechanism to mock, this can allow us to make CI much faster by adopting something like the following scheme: # Store and use snapshots of base-OS chroots (without modifications from *.repos or *.packages files) # Add the modifications from *.repos or *.packages files and snapshot them as well. This will make mock and CI run quite fast even if the *.repos or *.packages files are changed. Bottom line - this can essentially make mock run almost as fast as Docker (Almost because one case will still be slow - when we don't have a base snapshot and we need to build it, but if we decide that is an issue, we can think up ways to pre-build it) -- This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100087)