granthenke commented on a change in pull request #3732: NIFI-6662: Adding Kudu Lookup Service URL: https://github.com/apache/nifi/pull/3732#discussion_r324428922
########## File path: nifi-nar-bundles/nifi-kudu-bundle/nifi-kudu-controller-service/src/main/java/org/apache/nifi/controller/kudu/KuduLookupService.java ########## @@ -0,0 +1,323 @@ +/* + * 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. + */ +package org.apache.nifi.controller.kudu; + +import org.apache.kudu.ColumnSchema; +import org.apache.kudu.Schema; +import org.apache.kudu.Type; +import org.apache.kudu.client.AsyncKuduClient; +import org.apache.kudu.client.KuduClient; +import org.apache.kudu.client.KuduException; +import org.apache.kudu.client.KuduPredicate; +import org.apache.kudu.client.KuduScanner; +import org.apache.kudu.client.KuduTable; +import org.apache.kudu.client.RowResult; +import org.apache.nifi.annotation.documentation.CapabilityDescription; +import org.apache.nifi.annotation.documentation.Tags; +import org.apache.nifi.annotation.lifecycle.OnDisabled; +import org.apache.nifi.annotation.lifecycle.OnEnabled; +import org.apache.nifi.components.PropertyDescriptor; +import org.apache.nifi.controller.AbstractControllerService; +import org.apache.nifi.controller.ConfigurationContext; +import org.apache.nifi.controller.ControllerServiceInitializationContext; +import org.apache.nifi.expression.ExpressionLanguageScope; +import org.apache.nifi.kerberos.KerberosCredentialsService; +import org.apache.nifi.lookup.RecordLookupService; +import org.apache.nifi.processor.util.StandardValidators; +import org.apache.nifi.reporting.InitializationException; +import org.apache.nifi.security.krb.KerberosAction; +import org.apache.nifi.security.krb.KerberosKeytabUser; +import org.apache.nifi.security.krb.KerberosUser; +import org.apache.nifi.serialization.SimpleRecordSchema; +import org.apache.nifi.serialization.record.MapRecord; +import org.apache.nifi.serialization.record.Record; +import org.apache.nifi.serialization.record.RecordField; +import org.apache.nifi.serialization.record.RecordFieldType; +import org.apache.nifi.serialization.record.RecordSchema; + +import javax.security.auth.login.LoginException; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Base64; +import java.util.Collections; +import java.util.HashMap; +import java.util.HashSet; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.Set; +import java.util.concurrent.TimeUnit; +import java.util.stream.Collectors; + + +@CapabilityDescription("Lookup a record from Kudu Server associated with the specified key. Binary columns are base64 encoded. Only one matched row will be returned") +@Tags({"lookup", "enrich", "key", "value", "kudu"}) +public class KuduLookupService extends AbstractControllerService implements RecordLookupService { + + static final PropertyDescriptor KUDU_MASTERS = new PropertyDescriptor.Builder() + .name("kudu-lu-masters") + .displayName("Kudu Masters") + .description("Comma separated addresses of the Kudu masters to connect to.") + .required(true) + .addValidator(StandardValidators.NON_EMPTY_VALIDATOR) + .expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY) + .build(); + + static final PropertyDescriptor KERBEROS_CREDENTIALS_SERVICE = new PropertyDescriptor.Builder() + .name("kudu-lu-kerberos-credentials-service") + .displayName("Kerberos Credentials Service") + .description("Specifies the Kerberos Credentials to use for authentication") + .required(false) + .identifiesControllerService(KerberosCredentialsService.class) + .build(); + + static final PropertyDescriptor KUDU_OPERATION_TIMEOUT_MS = new PropertyDescriptor.Builder() + .name("kudu-lu-operations-timeout-ms") + .displayName("Kudu Operation Timeout") + .description("Default timeout used for user operations (using sessions and scanners)") + .required(false) + .defaultValue(AsyncKuduClient.DEFAULT_OPERATION_TIMEOUT_MS + "ms") + .addValidator(StandardValidators.TIME_PERIOD_VALIDATOR) + .expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY) + .build(); + + public static final PropertyDescriptor TABLE_NAME = new PropertyDescriptor.Builder() + .name("kudu-lu-table-name") + .displayName("Kudu Table Name") + .description("Name of the table to access.") + .required(true) + .defaultValue("default") + .addValidator(StandardValidators.NON_BLANK_VALIDATOR) + .expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY) + .build(); + + static final PropertyDescriptor RETURN_COLUMNS = new PropertyDescriptor.Builder() + .name("kudu-lu-return-cols") + .displayName("Kudu Return Columns") + .description("A comma-separated list of columns to return when scanning. To return all columns set to \"*\"") + .required(true) + .defaultValue("*") + .addValidator(StandardValidators.NON_BLANK_VALIDATOR) + .expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY) + .build(); + + + protected List<PropertyDescriptor> properties; + + protected KerberosCredentialsService credentialsService; + private volatile KerberosUser kerberosUser; + + protected String kuduMasters; + protected KuduClient kuduClient; + protected volatile String tableName; + protected volatile KuduTable table; + protected volatile List<String> columnNames; + + protected volatile RecordSchema resultSchema; + protected volatile Schema tableSchema; + + @Override + protected void init(final ControllerServiceInitializationContext context) { + final List<PropertyDescriptor> properties = new ArrayList<>(); + properties.add(KUDU_MASTERS); + properties.add(KERBEROS_CREDENTIALS_SERVICE); + properties.add(KUDU_OPERATION_TIMEOUT_MS); + properties.add(TABLE_NAME); + properties.add(RETURN_COLUMNS); + addProperties(properties); + this.properties = Collections.unmodifiableList(properties); + } + + protected void addProperties(List<PropertyDescriptor> properties) { + } + + protected void createKuduClient(ConfigurationContext context) throws LoginException { + final String kuduMasters = context.getProperty(KUDU_MASTERS).evaluateAttributeExpressions().getValue(); + final KerberosCredentialsService credentialsService = context.getProperty(KERBEROS_CREDENTIALS_SERVICE).asControllerService(KerberosCredentialsService.class); + + if (credentialsService == null) { + return; + } + + final String keytab = credentialsService.getKeytab(); + final String principal = credentialsService.getPrincipal(); + kerberosUser = loginKerberosUser(principal, keytab); + + final KerberosAction<KuduClient> kerberosAction = new KerberosAction<>(kerberosUser, () -> buildClient(kuduMasters, context), getLogger()); + this.kuduClient = kerberosAction.execute(); + } + protected KerberosUser loginKerberosUser(final String principal, final String keytab) throws LoginException { + final KerberosUser kerberosUser = new KerberosKeytabUser(principal, keytab); + kerberosUser.login(); + return kerberosUser; + } + protected KuduClient buildClient(final String masters, final ConfigurationContext context) { + final Integer operationTimeout = context.getProperty(KUDU_OPERATION_TIMEOUT_MS).asTimePeriod(TimeUnit.MILLISECONDS).intValue(); + + return new KuduClient.KuduClientBuilder(masters) + .defaultOperationTimeoutMs(operationTimeout) + .build(); + } + /** + * Establish a connection to a Kudu cluster. + * @param context the configuration context + * @throws InitializationException if unable to connect a Kudu cluster + */ + @OnEnabled + public void onEnabled(final ConfigurationContext context) throws InitializationException { + + try { + kuduMasters = context.getProperty(KUDU_MASTERS).evaluateAttributeExpressions().getValue(); + credentialsService = context.getProperty(KERBEROS_CREDENTIALS_SERVICE).asControllerService(KerberosCredentialsService.class); + + if (kuduClient == null) { + getLogger().debug("Setting up Kudu connection..."); + + createKuduClient(context); + getLogger().debug("Kudu connection successfully initialized"); + } + } catch(Exception ex){ + getLogger().error("Exception occurred while interacting with Kudu due to " + ex.getMessage(), ex); + throw new InitializationException(ex); + } + + tableName = context.getProperty(TABLE_NAME).evaluateAttributeExpressions().getValue(); + try { + table = kuduClient.openTable(tableName); + tableSchema = table.getSchema(); + columnNames = getColumns(context.getProperty(RETURN_COLUMNS).getValue()); + + //Result Schema + resultSchema = kuduSchemaToNiFiSchema(tableSchema, columnNames); + + } catch (KuduException e) { + throw new IllegalArgumentException(e); + } + } + + @Override + public Set<String> getRequiredKeys() { + return new HashSet<>(); + } + + @Override + protected List<PropertyDescriptor> getSupportedPropertyDescriptors() { + return properties; + } + @Override + public Optional<Record> lookup(Map<String, Object> coordinates) { + + //Scanner + KuduScanner.KuduScannerBuilder builder = kuduClient.newScannerBuilder(table); + + builder.setProjectedColumnNames(columnNames); + + //Only expecting one match + builder.limit(1); + + coordinates.forEach((key,value)-> + builder.addPredicate(KuduPredicate.newComparisonPredicate(tableSchema.getColumn(key), KuduPredicate.ComparisonOp.EQUAL, value)) + ); + + KuduScanner kuduScanner = builder.build(); + + //Run lookup + for ( RowResult row : kuduScanner){ + final Map<String, Object> values = new HashMap<>(); + for(String columnName : columnNames){ + Object object = row.getObject(columnName); + if(row.getColumnType(columnName) == Type.BINARY){ + object = Base64.getEncoder().encodeToString(row.getBinaryCopy(columnName)); + } + values.put(columnName, object); + } + return Optional.of(new MapRecord(resultSchema, values)); + } + + //No match + return Optional.empty(); + } + private List<String> getColumns(String columns){ Review comment: nit: add blank line above. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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