Major Description
Ozone datanode service could be started in two different way:
- as a standalone process
- as a datanode plugin
We tested the second scenarion by compiling both ozone + hadoop trunk together and created a combined artifact. But we have no more full hadoop distribution in the ozone release package any more. And we had no answer how it could be started with an existing hadoop release.
We need a well defined way to add the datanode-service to the classpath of the hadoop datanode.
I propose here to create a lightweight shaded artifact (and here the shading only combines all the classes together without package name refactoring) to make it easier to extend an existing hadoop installation.
In this patch I add the shade plugin execution to the ozone objectstore-service and the shaded file will be copied to the distribution.
A new docker-compose based execution environment (ozone-hdfs) demonstrates/tests how it could work.
Tested with hadoop 3.1.0 and datanode service could be started without any problem