Github user MikeThomsen commented on a diff in the pull request:
https://github.com/apache/nifi/pull/2615#discussion_r217899955
--- 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 --
So, I got it working and will share some artifacts tomorrow if I get a
chance so you can watch them in action. I'm thinking some of the behavior still
needs a second opinion on the flexibility/user-friendliness.
---
