feat: ES 7.x client support (#43)

* copy code verbatim from old module to the new module

* make changes in build.gradle

* make changes to the new module

* add new module in settings.gradle

build.gradle

@@ -39,6 +39,8 @@ project.ext.externalDependency = [
     'ebeanAgent': 'io.ebean:ebean-agent:11.27.1',
     'elasticSearchRest': 'org.elasticsearch.client:elasticsearch-rest-high-level-client:5.6.8',
     'elasticSearchTransport': 'org.elasticsearch.client:transport:5.6.8',
+    'elasticSearchRest7': 'org.elasticsearch.client:elasticsearch-rest-high-level-client:7.9.3',
+    'elasticSearchTransport7': 'org.elasticsearch.client:transport:7.9.3',
     'guava': 'com.google.guava:guava:27.0.1-jre',
     'h2': 'com.h2database:h2:1.4.196',
     'jacksonCore': 'com.fasterxml.jackson.core:jackson-core:2.9.7',
@@ -50,6 +52,7 @@ project.ext.externalDependency = [
     'junitJupiterEngine': "org.junit.jupiter:junit-jupiter-engine:$junitJupiterVersion",
     'lombok': 'org.projectlombok:lombok:1.18.12',
     'mockito': 'org.mockito:mockito-core:3.0.0',
+    'mockitoInline': 'org.mockito:mockito-inline:3.0.0',
     'neo4jHarness': 'org.neo4j.test:neo4j-harness:3.4.11',
     'neo4jJavaDriver': 'org.neo4j.driver:neo4j-java-driver:4.0.0',
     'parseqTest': 'com.linkedin.parseq:parseq:3.0.7:test',

dao-impl/elasticsearch-dao-7/build.gradle

@@ -0,0 +1,21 @@
+apply plugin: 'java'
+
+apply from: "$rootDir/gradle/java-publishing.gradle"
+
+dependencies {
+  compile project(':dao-api')
+
+  compile externalDependency.elasticSearchRest7
+  compile externalDependency.elasticSearchTransport7
+  compile externalDependency.guava
+  compile externalDependency.lombok
+  compile externalDependency.commonsIo
+  compile externalDependency.commonsLang
+  compile externalDependency.jacksonCore
+  compile externalDependency.jacksonDataBind
+
+  annotationProcessor externalDependency.lombok
+
+  testCompile project(':testing:test-models')
+  testCompile externalDependency.mockitoInline
+}

dao-impl/elasticsearch-dao-7/src/main/java/com/linkedin/metadata/dao/browse/BaseBrowseConfig.java

@@ -0,0 +1,57 @@
+package com.linkedin.metadata.dao.browse;
+
+import com.linkedin.data.schema.RecordDataSchema;
+import com.linkedin.data.template.RecordTemplate;
+import javax.annotation.Nonnull;
+
+
+public abstract class BaseBrowseConfig<DOCUMENT extends RecordTemplate> {
+  private static RecordDataSchema searchDocumentSchema;
+
+  @Nonnull
+  public String getBrowseDepthFieldName() {
+    return "browsePaths.length";
+  }
+
+  @Nonnull
+  public String getBrowsePathFieldName() {
+    return "browsePaths";
+  }
+
+  @Nonnull
+  public String getUrnFieldName() {
+    return "urn";
+  }
+
+  @Nonnull
+  public String getSortingField() {
+    return "urn";
+  }
+
+  @Nonnull
+  public String getRemovedField() {
+    return "removed";
+  }
+
+  public boolean hasFieldInSchema(@Nonnull String fieldName) {
+    return getSearchDocumentSchema().contains(fieldName);
+  }
+
+  private RecordDataSchema getSearchDocumentSchema() {
+    if (searchDocumentSchema == null) {
+      try {
+        searchDocumentSchema = getSearchDocument().newInstance().schema();
+      } catch (InstantiationException | IllegalAccessException e) {
+        throw new RuntimeException("Couldn't create an instance of the search document");
+      }
+    }
+    return searchDocumentSchema;
+  }
+
+  @Nonnull
+  public String getIndexName() {
+    return getSearchDocument().getSimpleName().toLowerCase();
+  }
+
+  public abstract Class<DOCUMENT> getSearchDocument();
+}