Github user MikeThomsen commented on a diff in the pull request: https://github.com/apache/nifi/pull/2615#discussion_r217899033 --- Diff: nifi-nar-bundles/nifi-elasticsearch-bundle/nifi-elasticsearch-client-service/src/main/java/org/apache/nifi/elasticsearch/ElasticSearchLookupService.java --- @@ -0,0 +1,258 @@ +/* + * 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.elasticsearch; + +import com.fasterxml.jackson.databind.ObjectMapper; +import org.apache.nifi.annotation.lifecycle.OnEnabled; +import org.apache.nifi.components.PropertyDescriptor; +import org.apache.nifi.controller.ConfigurationContext; +import org.apache.nifi.expression.ExpressionLanguageScope; +import org.apache.nifi.lookup.LookupFailureException; +import org.apache.nifi.lookup.LookupService; +import org.apache.nifi.processor.util.StandardValidators; +import org.apache.nifi.schema.access.SchemaNotFoundException; +import org.apache.nifi.serialization.JsonInferenceSchemaRegistryService; +import org.apache.nifi.serialization.record.MapRecord; +import org.apache.nifi.serialization.record.Record; +import org.apache.nifi.serialization.record.RecordSchema; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Collections; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.Set; +import java.util.stream.Collectors; + +public class ElasticSearchLookupService extends JsonInferenceSchemaRegistryService implements LookupService<Record> { + public static final PropertyDescriptor CLIENT_SERVICE = new PropertyDescriptor.Builder() + .name("el-rest-client-service") + .displayName("Client Service") + .description("An ElasticSearch client service to use for running queries.") + .identifiesControllerService(ElasticSearchClientService.class) + .required(true) + .build(); + public static final PropertyDescriptor INDEX = new PropertyDescriptor.Builder() + .name("el-lookup-index") + .displayName("Index") + .description("The name of the index to read from") + .required(true) + .expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY) + .addValidator(StandardValidators.NON_EMPTY_VALIDATOR) + .build(); + + public static final PropertyDescriptor TYPE = new PropertyDescriptor.Builder() + .name("el-lookup-type") + .displayName("Type") + .description("The type of this document (used by Elasticsearch for indexing and searching)") + .required(false) + .expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY) + .addValidator(StandardValidators.NON_EMPTY_VALIDATOR) + .build(); + + private ElasticSearchClientService clientService; + + private String index; + private String type; + private ObjectMapper mapper; + + private final List<PropertyDescriptor> DESCRIPTORS; + + public ElasticSearchLookupService() { + List<PropertyDescriptor> _desc = new ArrayList<>(); + _desc.addAll(super.getSupportedPropertyDescriptors()); + _desc.add(CLIENT_SERVICE); + _desc.add(INDEX); + _desc.add(TYPE); + DESCRIPTORS = Collections.unmodifiableList(_desc); + } + + @Override + @OnEnabled + public void onEnabled(final ConfigurationContext context) { + clientService = context.getProperty(CLIENT_SERVICE).asControllerService(ElasticSearchClientService.class); + index = context.getProperty(INDEX).evaluateAttributeExpressions().getValue(); + type = context.getProperty(TYPE).evaluateAttributeExpressions().getValue(); + mapper = new ObjectMapper(); + + super.onEnabled(context); + } + + @Override + protected List<PropertyDescriptor> getSupportedPropertyDescriptors() { + return DESCRIPTORS; + } + + @Override + public Optional<Record> lookup(Map<String, Object> coordinates) throws LookupFailureException { + Map<String, String> context = coordinates.entrySet().stream() + .collect(Collectors.toMap( + e -> e.getKey(), + e -> e.getValue().toString() + )); + return lookup(coordinates, context); + } + + @Override + public Optional<Record> lookup(Map<String, Object> coordinates, Map<String, String> context) throws LookupFailureException { + validateCoordinates(coordinates); + + try { + Record record; + if (coordinates.containsKey("_id")) { + record = getById((String)coordinates.get("_id"), context); + } else { + record = getByQuery(coordinates, context); + } + + return record == null ? Optional.empty() : Optional.of(record); + } catch (Exception ex) { + getLogger().error("Error during lookup.", ex); + throw new LookupFailureException(ex); + } + } + + private RecordSchema getSchemaFromCoordinates(Map<String, Object> coordinates) { + Map<String, String> variables = coordinates.entrySet().stream() + .collect(Collectors.toMap( + e -> e.getKey(), + e -> e.getValue().toString() + )); + try { + return getSchema(variables, null); + } catch (SchemaNotFoundException | IOException e) { + if (getLogger().isDebugEnabled()) { + getLogger().debug("Could not load schema, will create one from the results.", e); + } + return null; + } + } + + private void validateCoordinates(Map coordinates) throws LookupFailureException { + List<String> reasons = new ArrayList<>(); + + if (coordinates.containsKey("_id") && !(coordinates.get("_id") instanceof String)) { + reasons.add("_id was supplied, but it was not a String."); + } + + if (coordinates.containsKey("_id") && coordinates.size() > 1) { + reasons.add("When _id is used, it can be the only key used in the lookup."); + } + + if (reasons.size() > 0) { + String error = String.join("\n", reasons); + throw new LookupFailureException(error); + } + } + + private Record getById(final String _id, Map<String, String> context) throws IOException, LookupFailureException, SchemaNotFoundException { + Map<String, Object> query = new HashMap<String, Object>(){{ + put("query", new HashMap<String, Object>() {{ + put("match", new HashMap<String, String>(){{ + put("_id", _id); + }}); + }}); + }}; + + String json = mapper.writeValueAsString(query); + + SearchResponse response = clientService.search(json, index, type); + + if (response.getNumberOfHits() > 1) { + throw new LookupFailureException(String.format("Expected 1 response, got %d for query %s", + response.getNumberOfHits(), json)); + } else if (response.getNumberOfHits() == 0) { + return null; + } + + final Map<String, Object> source = (Map)response.getHits().get(0).get("_source"); + + RecordSchema toUse = getSchema(context, source, null); + + return new MapRecord(toUse, source); + } + + Map<String, Object> getNested(String key, Object value) { + String path = key.substring(0, key.lastIndexOf(".")); + + return new HashMap<String, Object>(){{ + put("path", path); + put("query", new HashMap<String, Object>(){{ + put("match", new HashMap<String, Object>(){{ + put(key, value); + }}); + }}); + }}; + } + + private Map<String, Object> buildQuery(Map<String, Object> coordinates) { + Map<String, Object> query = new HashMap<String, Object>(){{ + put("bool", new HashMap<String, Object>(){{ + put("must", coordinates.entrySet().stream() + .map(e -> new HashMap<String, Object>(){{ + if (e.getKey().contains(".")) { --- End diff -- > but got an error saying I was trying to do a nested query on a field that wasn't nested. I think you are. ES can be weird about detecting nested documents. I've only had consistent good results when explicitly defining them. I'll try to set up a test example.
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