Connect Superset to Druid

[stefanigel]

Acceptance Criteria

• Superset can connect to a Druid instance managed by Stackable

[fhennig]

Alright, so I just checked and this is already possible! Following the documentation:

1. Have a running druid and a running superset instance
2. In superset got to the Add Database form
3. Select to connect to Apache Druid
4. Enter the connect string: druid://simple-router-default:8888/druid/v2/sql
5. Done!

But I imagine that we'd want to use discovery. So we'd have a CR somewhere that is read by the superset-operator where we specify which druid cluster to connect to and then the operator configures the superset instance to connect to the druid cluster. This also requires discovery for Druid.

[fhennig]

Alright, druid discovery is on the way.

For setting up the connection in superset programmatically, I found this nifty feature tucked away in the documentation under "miscellaneous": https://superset.apache.org/docs/miscellaneous/importing-exporting-datasources Importing and exporting datasources from/to yaml files! We can use an import from a file inside the init container probably to set it up.

[fhennig]

Done
#71