CI/CD Transformation

Collect documents, questions, and comments related to transforming Anuket's CI/CD environment.

Weekly Technical Discuss - Aug. 10th, 2020

There is an overall objective within LFN to consolidate resources (processes / costs / support) and improve developer resources. New LFN projects are encouraged to move to GitLab-CI.
Gerrit is used in our upstream community (OpenStack) and along with Jenkins adds a lot of features/functionality for developers - more flexibility but requires additional maintenance.
The integration team in ONAP is currently using GitLab-CI to gate releases: This required use of so-cat to watch changes in Gerrit and communicate back results. ONAP is possibly looking into GitLab-CI in the longer term
Jenkins JJB are very powerful and Jenkins fits the test daily jobs (not linked to any code repo)
OPNFV could have rather implement the JJB middleware (JJB per branch) in Releng.
Gerrit is felt to be more flexible than GitLab for patch review management (see opendev.org)
Functest job scheduling requires more work with GitLab-CI (Lots of rework to migrate JJB for Functest)

Weekly Technical Discuss - Aug. 17th, 2020

Question regarding limiting concurrency of job (ex: 4 out of 10). GitLab responded there are multiple ways this could be solved. Some suggestions were:
- Using labels and runners
- Environment tags
- Limiting resources
Concern expressed around GitLab jobs having to clone code - Suggestion from GitLab team was to use `GIT_STRATEGY: none`
There was some concern around the timing of the transition - Lots of changes going on in OPNFV as a project (CNTT & FMO)
Airship, Kuberef interested in doing some proof-of-concept work in GitLab-CI
Functest prefers Gerrit due to the patchset dependency workflow
Because jobs are linked to the repository, branch specific CI would need to be backported to support previous releases.