Log pipeline CI is pushing duplicate images

[timothyb89]

It seems the log pipeline CI is pushing duplicate images in some cases.

For example: https://hub.docker.com/r/monasca/agent-collector/tags/

Two images (master-20171019-195001 and master-20171019-194745) were pushed ~3 minutes apart. The build log for that patch shows that the log pipeline job built and pushed the two agent containers, even though the metrics pipeline already published the images: https://travis-ci.org/monasca/monasca-docker/jobs/290158679

[Brandstetter]

I detected the same issue...question is: should the metric pipeline build and push log components? Should be the task of the log pipeline, shouldn't it?

[timothyb89]

Ideally I think metrics should push metrics and logs should push logs, though it may be simpler to implement if we picked one or the other.