DRILL-6494: Drill Plugins Handler - Storage Plugins Handler service is used op the Drill start-up stage and it updates storage plugins configs from storage-plugins-override.conf file. If plugins configs are present in the persistence store - they are updated, otherwise bootstrap plugins are updated and the result configs are loaded to persistence store. If the enabled status is absent in the storage-plugins-override.conf file, the last plugin config enabled status persists. - 'drill.exec.storage.action_on_plugins_override_file' Boot option is added. This is the action, which should be performed on the storage-plugins-override.conf file after successful updating storage plugins configs. Possible values are: "none" (default), "rename" and "remove". - The "NULL" issue with updating Hive plugin config by REST is solved. But clients are still being instantiated for disabled plugins - DRILL-6412. - "org.honton.chas.hocon:jackson-dataformat-hocon" library is added for the proper deserializing HOCON conf file - additional refactoring: "com.typesafe:config" and "org.apache.commons:commons-lang3" are placed into DependencyManagement block with proper versions; correct properties for metrics in "drill-override-example.conf" are specified
DRILL-1133: Default cp and dfs storage plugin instances do not appear in Drill Web UI after installing Drill. * Modified StoragePluginRegistry to scan for ALL 'bootstrap-storage-plugins.json' files in the classpath instead of only the first one. * Moved 'hbase' and 'hive' plugin instance definitions to their own module from 'java-exec'. * Renamed the test storage plugin instances to 'dfs_test' and 'hive_test' and updated the test cases to reflect this change.