Add web ui route to schema for SparkCluster

[elmiko]

Description:

When a user has requested a spark cluster with the web ui exposed, it would be nice to associate the exposed route, where available, in the cluster schema data. This would prevent consumers of the SparkCluster schema from needing an extra call to determine the URL.

One potential downside of this is that it might require monitoring any route objects that get created to ensure that the spark cluster object is updated appropriately.

Question:

I think this would be a nice feature to help with the creation of downstream tooling, I am not sure how far from the sparkcluster.k8s.io schema we want to stray or how we might consider these type of modifications in general. I'm curious to hear opinions about this feature, and would like to know if this is a welcome addition?

[elmiko]

additional comment

~after reviewing the code, i am less certain about what the sparkWebUI option is doing.~ i am wondering if this should be creating routes automatically on openshift?

i think this would be a nice convenience on openshift

[jkremser]

Creating the route/ingress and writing the URL back to the corresponding sparkcluster would allow another useful printer column (additionalPrinterColumns in CRD) as it was introduced here https://github.com/radanalyticsio/spark-operator/issues/246

Drawback is making things more complex, because updating the CR would trigger another (no-op) event in the operator (onModify)