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

closes #1345

3 files changed, 85 insertions, 13 deletions

diff --git a/distribution/src/assemble/bin.xml b/distribution/src/assemble/bin.xml
index e044801f9..712f3ec59 100644
--- a/distribution/src/assemble/bin.xml
+++ b/distribution/src/assemble/bin.xml
@@ -420,6 +420,11 @@
       <source>src/resources/drill-on-yarn-example.conf</source>
       <outputDirectory>conf</outputDirectory>
       <fileMode>0640</fileMode>
-   </file>
+    </file>
+    <file>
+      <source>src/resources/storage-plugins-override-example.conf</source>
+      <outputDirectory>conf</outputDirectory>
+      <fileMode>0640</fileMode>
+    </file>
   </files>
 </assembly>
diff --git a/distribution/src/resources/drill-override-example.conf b/distribution/src/resources/drill-override-example.conf
index fa2e39555..296cd8b60 100644
--- a/distribution/src/resources/drill-override-example.conf
+++ b/distribution/src/resources/drill-override-example.conf
@@ -58,17 +58,10 @@ drill.exec: {
         batch.size: 4000
       },
       partition.column.label: "dir"
-    }
-  },
-  metrics : {
-    context: "drillbit",
-    jmx: {
-      enabled : true
     },
-    log: {
-      enabled : false,
-      interval : 60
-    }
+    # The action on the storage-plugins-override.conf after it's use.
+    # Possible values are "none" (default), "rename", "remove"
+    action_on_plugins_override_file: "none"
   },
   zk: {
 	connect: "localhost:2181",
@@ -252,6 +245,15 @@ drill.exec: {
     #ssl provider. May be "JDK" or "OPENSSL". Default is "JDK"
     provider: "JDK"
   }
-}
-
+},
 
+drill.metrics : {
+  context: "drillbit",
+  jmx: {
+    enabled : true
+  },
+  log: {
+    enabled : false,
+    interval : 60
+  }
+}
diff --git a/distribution/src/resources/storage-plugins-override-example.conf b/distribution/src/resources/storage-plugins-override-example.conf
new file mode 100644
index 000000000..360ba2c0a
--- /dev/null
+++ b/distribution/src/resources/storage-plugins-override-example.conf
@@ -0,0 +1,65 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This file involves storage plugins configs, which can be updated on the Drill start-up.
+# This file is in HOCON format, see https://github.com/typesafehub/config/blob/master/HOCON.md for more information.
+
+  "storage":{
+    cp: {
+      type: "file",
+      connection: "classpath:///",
+      formats: {
+        "csv" : {
+          type: "text",
+          extensions: [ "csv" ],
+          delimiter: ","
+        }
+      }
+    }
+  }
+  "storage":{
+    dfs: {
+      type: "file",
+      connection: "hdfs:///",
+      workspaces: {
+        "root": {
+          "location": "/",
+          "writable": false,
+          "defaultInputFormat": null,
+          "allowAccessOutsideWorkspace": false
+        }
+      },
+      formats: {
+        "parquet": {
+          "type": "parquet"
+        }
+      },
+      enabled: false
+    }
+  }
+  "storage":{
+    mongo : {
+      type:"mongo",
+      connection:"mongodb://test_host:27017/",
+      enabled: true
+    }
+  }
+  "storage": {
+    openTSDB: {
+      type: "openTSDB",
+      connection: "http://localhost:8888",
+      enabled: true
+    }
+  }