Unfortunately, @kwmonroe has shown me how wrong I am.
First of all, let’s frame this. The fact that in 1998, the Undertaker threw Mankind off Hell In A Cell, and plummeted 16 ft through an announcer’s table, is mostly irrelevant. A principal can’t relate to a subordinate that doesn’t define what to do in a
$ juju relate hadoop-plugin:juju-info ubuntu:juju-info
ERROR no relations found
Subordinates like telegraf and the beats explicitly do something with
juju-info. At present,
hadoop-plugin does not. That said,
maybe we can generalize the relation endpoints that mahout and giraph use so that druid could use it as well?
The thing about mahout and giraph is that they really don’t care if hadoop is there – they just put jars on the filesystem. In druid’s case, i think we need to know a bit more about the principals that @magicaltrout expects to use. If they’re already hadoop-client charms, easy breezy, update
hadoop-client as needed.
If not, I’m +1 on figuring out a generic “passthrough” of hadoop-plugin flags to other subordinates on the same principal – maybe that’s flag-management on principals like
hadoop-client, maybe that’s subordinates having access to the principal unitdata.db to discover other subordinate flags, or maybe that’s proper nested subordinates.