[feature request] download logs from all the containers

[huijunw]

A feature request from out customer: a way to download the logs from all of the containers?

The customer would like to search something in the logs. He has to narrow down search container range first, which may not be always easy to do.

[aahmed-se]

generally that's not a thing distributed systems do, I guess one would write a script to do it, but ideally log collectors should be deployed in the cluster

[maosongfu]

Another thought is to see whether we could integrate with existing tool/service providing similar features, like LogLens.

[Code0x58]

This seems very close to https://github.com/apache/incubator-heron/issues/1453 which I also think can be closed

[nicknezis]

In the past we have used a simple script to gather all logs. Perhaps this could be a feature added in the Heron CLI? I would be interested in the ability to add a log collector alongside a running topology. For Kubernetes, I've thought of ways to add a sidecar promtail instance to feed Loki. But I feel like solutions like this should be a seperate issue.

@huijunw Would you want this issue to reflect a feature request on the Heron CLI? Or can we close this issue?