[rdo-list] RDO Phase2 testing - DLRN API transition

[Attila Darazs]

Matt Young and I had a conversation about about how to move RDO Phase2 
over to use DLRN API seamlessly and we had some unanswered question that 
Javier helped to answer, so I'm posting the information here for future 
reference.

There's this file here on the DLRN server called "promote.sh": 
https://github.com/rdo-infra/ci-config/blob/master/jenkins/jobs/scripts/promote-repo-promote.sh#L4

That file is deployed using puppet-dlrn, it's in 
https://github.com/rdo-infra/puppet-dlrn/blob/master/files/promote.sh

The last line is something that Matt relies on when starting new 
promotion jobs. Once we switch Phase1 to promote using DLRN API call, 
this file won't be updated.

We can probably make a change in the puppet-dlrn role to create cronjob 
that uses a DLRN API call to periodically update that file with the 
history of promotions until the Phase2 jobs transitions to trigger by a 
different method.

I suggest to use what Phase1 does and check if the delorean.repo file 
changes:

https://github.com/rdo-infra/ci-config/blob/master/jenkins/jobs/promote-pike-current-tripleo.yml#L56-L61

Best regards,
Attila