NIFI-4443 Increase StoreInKiteDataset flexibility

* The configuration property CONF_XML_FILE now support Expression
  Language and reuse a Hadoop validator;
* The ADDITIONAL_CLASSPATH_RESOURCES property has been added, so that
  things such as writing to Azure Blob Storage should become possible.

This closes #2186.

Signed-off-by: Bryan Bende <bbende@apache.org>

nifi-nar-bundles/nifi-kite-bundle/nifi-kite-processors/pom.xml

@@ -281,6 +281,10 @@
             <scope>test</scope>
             <version>${kite.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.apache.nifi</groupId>
+            <artifactId>nifi-hadoop-utils</artifactId>
+        </dependency>
 
     </dependencies>
 

nifi-nar-bundles/nifi-kite-bundle/nifi-kite-processors/src/main/java/org/apache/nifi/processors/kite/AbstractKiteProcessor.java

@@ -37,7 +37,7 @@ import org.apache.nifi.components.ValidationResult;
 import org.apache.nifi.components.Validator;
 import org.apache.nifi.processor.AbstractProcessor;
 import org.apache.nifi.processor.ProcessContext;
-import org.apache.nifi.processor.util.StandardValidators;
+import org.apache.nifi.processors.hadoop.HadoopValidators;
 import org.kitesdk.data.DatasetNotFoundException;
 import org.kitesdk.data.Datasets;
 import org.kitesdk.data.SchemaNotFoundException;
@@ -47,33 +47,16 @@ import org.kitesdk.data.spi.DefaultConfiguration;
 abstract class AbstractKiteProcessor extends AbstractProcessor {
 
     private static final Splitter COMMA = Splitter.on(',').trimResults();
-    protected static final Validator FILES_EXIST = new Validator() {
-        @Override
-        public ValidationResult validate(String subject, String configFiles,
-                ValidationContext context) {
-            if (configFiles != null && !configFiles.isEmpty()) {
-                for (String file : COMMA.split(configFiles)) {
-                    ValidationResult result = StandardValidators.FILE_EXISTS_VALIDATOR
-                            .validate(subject, file, context);
-                    if (!result.isValid()) {
-                        return result;
-                    }
-                }
-            }
-            return new ValidationResult.Builder()
-                    .subject(subject)
-                    .input(configFiles)
-                    .explanation("Files exist")
-                    .valid(true)
-                    .build();
-        }
-    };
 
     protected static final PropertyDescriptor CONF_XML_FILES
             = new PropertyDescriptor.Builder()
             .name("Hadoop configuration files")
-            .description("A comma-separated list of Hadoop configuration files")
+            .displayName("Hadoop configuration Resources")
-            .addValidator(FILES_EXIST)
+            .description("A file or comma separated list of files which contains the Hadoop file system configuration. Without this, Hadoop "
+                    + "will search the classpath for a 'core-site.xml' and 'hdfs-site.xml' file or will revert to a default configuration.")
+            .required(false)
+            .addValidator(HadoopValidators.ONE_OR_MORE_FILE_EXISTS_VALIDATOR)
+            .expressionLanguageSupported(true)
             .build();
 
     protected static final Validator RECOGNIZED_URI = new Validator() {
@@ -163,7 +146,7 @@ abstract class AbstractKiteProcessor extends AbstractProcessor {
     protected static final Validator SCHEMA_VALIDATOR = new Validator() {
         @Override
         public ValidationResult validate(String subject, String uri, ValidationContext context) {
-            Configuration conf = getConfiguration(context.getProperty(CONF_XML_FILES).getValue());
+            Configuration conf = getConfiguration(context.getProperty(CONF_XML_FILES).evaluateAttributeExpressions().getValue());
             String error = null;
 
             final boolean elPresent = context.isExpressionLanguageSupported(subject) && context.isExpressionLanguagePresent(uri);
@@ -195,7 +178,7 @@ abstract class AbstractKiteProcessor extends AbstractProcessor {
     protected void setDefaultConfiguration(ProcessContext context)
             throws IOException {
         DefaultConfiguration.set(getConfiguration(
-                context.getProperty(CONF_XML_FILES).getValue()));
+                context.getProperty(CONF_XML_FILES).evaluateAttributeExpressions().getValue()));
     }
 
     protected static Configuration getConfiguration(String configFiles) {

nifi-nar-bundles/nifi-kite-bundle/nifi-kite-processors/src/main/java/org/apache/nifi/processors/kite/StoreInKiteDataset.java

@@ -38,6 +38,7 @@ import org.apache.nifi.processor.ProcessSession;
 import org.apache.nifi.processor.Relationship;
 import org.apache.nifi.processor.exception.ProcessException;
 import org.apache.nifi.processor.io.InputStreamCallback;
+import org.apache.nifi.processor.util.StandardValidators;
 import org.apache.nifi.util.StopWatch;
 import org.kitesdk.data.DatasetIOException;
 import org.kitesdk.data.DatasetWriter;
@@ -79,10 +80,21 @@ public class StoreInKiteDataset extends AbstractKiteProcessor {
             .required(true)
             .build();
 
+    public static final PropertyDescriptor ADDITIONAL_CLASSPATH_RESOURCES = new PropertyDescriptor.Builder()
+            .name("additional-classpath-resources")
+            .displayName("Additional Classpath Resources")
+            .description("A comma-separated list of paths to files and/or directories that will be added to the classpath. When specifying a " +
+                    "directory, all files with in the directory will be added to the classpath, but further sub-directories will not be included.")
+            .required(false)
+            .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+            .dynamicallyModifiesClasspath(true)
+            .build();
+
     private static final List<PropertyDescriptor> PROPERTIES
             = ImmutableList.<PropertyDescriptor>builder()
             .addAll(AbstractKiteProcessor.getProperties())
             .add(KITE_DATASET_URI)
+            .add(ADDITIONAL_CLASSPATH_RESOURCES)
             .build();
 
     private static final Set<Relationship> RELATIONSHIPS

nifi-nar-bundles/nifi-kite-bundle/nifi-kite-processors/src/test/java/org/apache/nifi/processors/kite/TestConfigurationProperty.java

@@ -21,6 +21,7 @@ package org.apache.nifi.processors.kite;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import org.apache.avro.generic.GenericData.Record;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.nifi.processor.ProcessContext;
 import org.apache.nifi.util.TestRunner;
@@ -29,8 +30,12 @@ import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
+import org.junit.After;
 import org.junit.rules.TemporaryFolder;
+import org.kitesdk.data.DatasetDescriptor;
+import org.kitesdk.data.Datasets;
 import org.kitesdk.data.spi.DefaultConfiguration;
+import org.kitesdk.data.Dataset;
 
 public class TestConfigurationProperty {
 
@@ -38,6 +43,9 @@ public class TestConfigurationProperty {
     public final TemporaryFolder temp = new TemporaryFolder();
     public File confLocation;
 
+    private String datasetUri = null;
+    private Dataset<Record> dataset = null;
+
     @Before
     public void saveConfiguration() throws IOException {
         Configuration conf = new Configuration(false);
@@ -49,6 +57,20 @@ public class TestConfigurationProperty {
         out.close();
     }
 
+    @Before
+    public void createDataset() throws Exception {
+        DatasetDescriptor descriptor = new DatasetDescriptor.Builder()
+                .schema(TestUtil.USER_SCHEMA)
+                .build();
+        this.datasetUri = "dataset:file:" + temp.newFolder("ns", "temp").toString();
+        this.dataset = Datasets.create(datasetUri, descriptor, Record.class);
+    }
+
+    @After
+    public void deleteDataset() throws Exception {
+        Datasets.delete(datasetUri);
+    }
+
     @Test
     public void testConfigurationCanary() throws IOException {
         TestRunner runner = TestRunners.newTestRunner(StoreInKiteDataset.class);
@@ -73,4 +95,18 @@ public class TestConfigurationProperty {
                 AbstractKiteProcessor.CONF_XML_FILES, temp.newFile().toString());
         runner.assertNotValid();
     }
+
+    @Test
+    public void testConfigurationExpressionLanguage() throws IOException {
+        TestRunner runner = TestRunners.newTestRunner(StoreInKiteDataset.class);
+        runner.setProperty(
+                AbstractKiteProcessor.CONF_XML_FILES, "${filename:substring(0,0):append('pom.xml')}");
+        runner.setProperty(
+                StoreInKiteDataset.KITE_DATASET_URI, datasetUri);
+        runner.assertValid();
+        // botch the Expression Language evaluation
+        runner.setProperty(
+                AbstractKiteProcessor.CONF_XML_FILES, "${filename:substring(0,0):");
+        runner.assertNotValid();
+    }
 }