Added flowLabel, includeLabelInRouter flow fields + relabel output

[gvizdpeter]

Fixes #1115

[gvizdpeter]

@pepov This is probably logic, that you requested 82747df ,
if FlowLabel is empty, automatically include flow in router unless explicitly defined to exclude
if FlowLabel is not empty, automatically exclude flow from router unless explicitly defined to include
Unfortunately this logic can not be in builder.go, as there is flow label already calculated.

Or do you want to completely remove includeLabelInRouter param from user control, and drive it only by existence of FlowLabel?

[pepov]

With some minor fixes, this is exactly what I was asking for, thank you!

[gvizdpeter]

Thank you as well, hope it is OK now

[pepov]

@gvizdpeter thanks for the nice contribution, merging this now!

[pepov]

Created a follow up issue for the docs: kube-logging/kube-logging.github.io#131

@gvizdpeter could you please help with the documentation part? No need to figure out the right place or the proper wording, just creating a sketch with a general description and the most important use-cases.

[gvizdpeter]

Hello @pepov I will try to add something to opened issues.

[Jorricks]

Does someone happen to have a nice example of this with the concat plugin using timeout_label and then the relabel in action?

[pepov]

If concat produces messages with new labels, then you don't need relabel, just a flow with the label you want to redirect timeouted messages:

apiVersion: logging.banzaicloud.io/v1beta1
kind: Flow
metadata:
  name: concat-timeout-flow
spec:
  flowLabel: '@concat-timeout'
  includeLabelInRouter: false
  localOuputs: ...

Maybe the question is what do you want to do with those messages ran into timeout?