[JIRA] (OVIRT-2189) Imrpove mock_runner.sh speed, containment and maintainability

Imrpove mock_runner.sh speed, containment and maintainability ------------------------------------------------------------- Key: OVIRT-2189 URL: https://ovirt-jira.atlassian.net/browse/OVIRT-2189 Project: oVirt - virtualization made easy Issue Type: Epic Components: mock_runner Reporter: Barak Korren Assignee: infra {{mock_runner.sh}} is the core of all STDCI, yet it has multiple issues and shortcomings that make it less the ideal. Many of the ways {{mock_runner.sh}} does things have to do with the way {{mock}} worked a few years ago when the script was first written. However, {{mock}} had been improved over time, and the new features it includes allow for making improvements to the way {{mock_runner.sh}} works without a very big time investment. h3. Acceptance Criteria # {{mock_runner.sh}} uses systemsd-nspawn for containment rather then simple chroot # {{mock_runner.sh}} can start a chroot from cache in less then 10 seconds. # {{mock_runner.sh}} does not reinstall the whole chroot if just a few packages in the *.packages file were changed. # {{mock_runner.sh}} invokes {{mock}} only once when it runs # {{mock_runner.sh}} can use the mock config files that are shipped with {{mock}} directly without the CI team having to maintain their own set of files.