NIFI-7833 - Add Ozone support in Hadoop components where appropriate

[pvillard31]

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Enables X functionality; fixes bug NIFI-YYYY.

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[pvillard31]

Tested against a cluster where Ozone 1.0.0 was installed with Kerberos enabled.

• Added core-site, and ozone-site XML files as configuration files
• Ensured that the proper properties are indicated in core-site.xml

<property>
  <name>fs.AbstractFileSystem.o3fs.impl</name>
  <value>org.apache.hadoop.fs.ozone.OzFs</value>
</property>
<property>
  <name>fs.defaultFS</name>
  <value>o3fs://bucket.volume</value>
</property>

It's important to note that for the FetchHDFS processor, it's important to specify the fully qualified path and not just the relative path to the bucket. In other words, ListHDFS will list a file with path equal to / and name equal to foo.txt, if leaving the default property for FetchHDFS, you might get this error:

2020-09-25 11:16:24,155 WARN org.apache.nifi.controller.tasks.ConnectableTask: Administratively Yielding FetchHDFS[id=c04a869b-0174-1000-0000-00003e0aa21b] due to uncaught Exception: java.lang.StringIndexOutOfBoundsException: String index out of range: -1
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
	at java.lang.String.substring(String.java:1931)
	at org.apache.hadoop.fs.ozone.BasicOzoneFileSystem.pathToKey(BasicOzoneFileSystem.java:748)
	at org.apache.hadoop.fs.ozone.BasicOzoneFileSystem.open(BasicOzoneFileSystem.java:212)
	at org.apache.nifi.processors.hadoop.FetchHDFS$1.run(FetchHDFS.java:161)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:360)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1710)
	at org.apache.nifi.processors.hadoop.FetchHDFS.onTrigger(FetchHDFS.java:140)
	at org.apache.nifi.processor.AbstractProcessor.onTrigger(AbstractProcessor.java:27)
	at org.apache.nifi.controller.StandardProcessorNode.onTrigger(StandardProcessorNode.java:1176)
	at org.apache.nifi.controller.tasks.ConnectableTask.invoke(ConnectableTask.java:213)
	at org.apache.nifi.controller.scheduling.TimerDrivenSchedulingAgent$1.run(TimerDrivenSchedulingAgent.java:117)
	at org.apache.nifi.engine.FlowEngine$2.run(FlowEngine.java:110)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

You'll need to change the property in the FetchHDFS processor to use o3fs://bucket.volume/${path}/${name} instead of the default ${path}/${name}.

[bbende]

Looks good, will merge, thanks!