Expose user agent and pass header through in requests

java-client/src/main/java/co/elastic/clients/base/Transport.java

@@ -41,4 +41,6 @@ <RequestT, ResponseT, ErrorT> CompletableFuture<ResponseT> performRequestAsync(
  );
 
  JsonpMapper jsonpMapper();
+
+ String userAgent();
 }

java-client/src/main/java/co/elastic/clients/base/UserAgent.java

@@ -0,0 +1,95 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. 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 co.elastic.clients.base;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Properties;
+
+/**
+ * Models a user agent, consisting of a name, version,
+ * and optional key-value metadata.
+ */
+public class UserAgent {
+
+ static final String DEFAULT_NAME = "elasticsearch-java";
+
+ // The client version is loaded from the 'version.properties' file
+ static final String DEFAULT_VERSION;
+ static {
+ InputStream in = UserAgent.class.getResourceAsStream("/co.elastic.clients.elasticsearch/version.properties");
+ if (in != null) {
+ Properties prop = new Properties();
+ String version;
+ try {
+ prop.load(in);
+ version = prop.getProperty("version", "?");
+ } catch (IOException e) {
+ // Unable to read properties file
+ version = "?";
+ }
+ DEFAULT_VERSION = version;
+ }
+ else {
+ // Unable to locate properties file
+ DEFAULT_VERSION = "?";
+ }
+ // TODO: log error if DEFAULT_VERSION now equals "?"
+ }
+
+ // Default user agent, constructed from default repo name and version
+ public static final UserAgent DEFAULT = new UserAgent(DEFAULT_NAME, DEFAULT_VERSION);
+
+ private final String name;
+ private final String version;
+ private final Map<String, String> metadata;
+
+ public UserAgent(String name, String version, Map<String, String> metadata) {
+ this.name = name;
+ this.version = version;
+ this.metadata = metadata;
+ }
+
+ public UserAgent(String repoName, String version) {
+ this(repoName, version, Collections.emptyMap());
+ }
+
+ @Override
+ public String toString() {
+ if (metadata.isEmpty()) {
+ return String.format("%s/%s", name, version);
+ }
+ else {
+ StringBuilder metadataString = new StringBuilder();
+ for (Map.Entry<String, String> entry : metadata.entrySet()) {
+ if (metadataString.length() > 0) {
+ metadataString.append("; ");
+ }
+ metadataString.append(entry.getKey());
+ metadataString.append(' ');
+ metadataString.append(entry.getValue());
+ }
+ return String.format("%s/%s (%s)", name, version, metadataString);
+ }
+ }
+
+}

java-client/src/main/java/co/elastic/clients/base/rest_client/RestClientTransport.java

@@ -25,11 +25,13 @@
 import co.elastic.clients.base.ElasticsearchCatRequest;
 import co.elastic.clients.base.Endpoint;
 import co.elastic.clients.base.Transport;
+import co.elastic.clients.base.UserAgent;
 import co.elastic.clients.json.JsonpDeserializer;
 import co.elastic.clients.json.JsonpMapper;
 import co.elastic.clients.json.NdJsonpSerializable;
 import jakarta.json.stream.JsonGenerator;
 import jakarta.json.stream.JsonParser;
+import org.apache.http.Header;
 import org.apache.http.entity.ByteArrayEntity;
 import org.apache.http.entity.ContentType;
 import org.elasticsearch.client.Cancellable;
@@ -51,12 +53,30 @@ public class RestClientTransport implements Transport {
 
  private final RestClient restClient;
  private final JsonpMapper mapper;
- private RequestOptions requestOptions;
+ private final RequestOptions requestOptions;
 
- public RestClientTransport(RestClient restClient, JsonpMapper mapper, @Nullable RequestOptions options) {
+ public RestClientTransport(RestClient restClient, JsonpMapper mapper, @Nullable RequestOptions options,
+ @Nullable UserAgent userAgent) {
  this.restClient = restClient;
  this.mapper = mapper;
- this.requestOptions = options;
+ RequestOptions baseOptions = options == null ? RequestOptions.DEFAULT : options;
+ String manualUserAgent = findUserAgentIn(baseOptions);
+ if (manualUserAgent == null && userAgent == null) {
+ this.requestOptions = baseOptions.toBuilder().addHeader("User-Agent", UserAgent.DEFAULT.toString()).build();
+ }
+ else if (manualUserAgent == null) {
+ this.requestOptions = baseOptions.toBuilder().addHeader("User-Agent", userAgent.toString()).build();
+ }
+ else if (userAgent == null) {
+ this.requestOptions = baseOptions;
+ }
+ else {
+ throw new IllegalArgumentException("Multiple user agents specified");
+ }
+ }
+
+ public RestClientTransport(RestClient restClient, JsonpMapper mapper, @Nullable RequestOptions options) {
+ this(restClient, mapper, options, null);
  }
 
  public RestClientTransport(RestClient restClient, JsonpMapper mapper) {
@@ -84,16 +104,41 @@ public RestClientTransport withRequestOptions(Function<RequestOptions.Builder, R
  return withRequestOptions(fn.apply(builder).build());
  }
 
+ public RestClientTransport withUserAgent(UserAgent userAgent) {
+ return new RestClientTransport(this.restClient, this.mapper, this.requestOptions, userAgent);
+ }
+
  @Override
  public JsonpMapper jsonpMapper() {
  return mapper;
  }
 
+ /**
+ * Find and return the first header value which is keyed under any
+ * case-insensitive variant of "User-Agent".
+ *
+ * @return user agent string
+ */
+ @Override
+ public String userAgent() {
+ return findUserAgentIn(requestOptions);
+ }
+
  @Override
  public void close() throws IOException {
  this.restClient.close();
  }
 
+ private static String findUserAgentIn(RequestOptions options) {
+ // TODO: move this into RequestOptions?
+ for (Header header : options.getHeaders()) {
+ if (header.getName().equalsIgnoreCase("User-Agent")) {
+ return header.getValue();
+ }
+ }
+ return null;
+ }
+
  public <RequestT, ResponseT, ErrorT> ResponseT performRequest(
  RequestT request,
  Endpoint<RequestT, ResponseT, ErrorT> endpoint
@@ -154,9 +199,7 @@ private <RequestT> org.elasticsearch.client.Request prepareLowLevelRequest(
 
  org.elasticsearch.client.Request clientReq = new org.elasticsearch.client.Request(method, path);
  clientReq.addParameters(params);
- if (requestOptions != null) {
- clientReq.setOptions(requestOptions);
- }
+ clientReq.setOptions(requestOptions);
 
  // Request-type specific parameters.
  if (request instanceof ElasticsearchCatRequest) {

java-client/src/test/java/co/elastic/clients/base/UserAgentTest.java

@@ -0,0 +1,77 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. 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 co.elastic.clients.base;
+
+import co.elastic.clients.base.rest_client.RestClientTransport;
+import org.apache.http.HttpHost;
+import org.elasticsearch.client.RequestOptions;
+import org.elasticsearch.client.RestClient;
+import org.junit.Test;
+
+import static co.elastic.clients.base.UserAgent.DEFAULT_NAME;
+import static co.elastic.clients.base.UserAgent.DEFAULT_VERSION;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThrows;
+
+public class UserAgentTest {
+
+ private static final String DEFAULT_USER_AGENT = String.format("%s/%s", DEFAULT_NAME, DEFAULT_VERSION);
+
+ private static final String CUSTOM_NAME = "ÜberClient";
+ private static final String CUSTOM_VERSION = "1.0.13";
+ private static final String CUSTOM_USER_AGENT = String.format("%s/%s", CUSTOM_NAME, CUSTOM_VERSION);
+
+ private static final String CUSTOM_NAME_2 = "MegaClient";
+ private static final String CUSTOM_VERSION_2 = "6.7.8";
+
+ @Test
+ public void testDefaultUserAgent() throws Exception {
+ RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
+ Transport transport = new RestClientTransport(restClient, null);
+ assertEquals(DEFAULT_USER_AGENT, transport.userAgent());
+ }
+
+ @Test
+ public void testCustomUserAgent() throws Exception {
+ RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
+ Transport transport = new RestClientTransport(restClient, null, null,
+ new UserAgent(CUSTOM_NAME, CUSTOM_VERSION));
+ assertEquals(CUSTOM_USER_AGENT, transport.userAgent());
+ }
+
+ @Test
+ public void testManualUserAgent() throws Exception {
+ RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
+ Transport transport = new RestClientTransport(restClient, null,
+ RequestOptions.DEFAULT.toBuilder().addHeader("User-Agent", CUSTOM_USER_AGENT).build());
+ assertEquals(CUSTOM_USER_AGENT, transport.userAgent());
+ }
+
+ @Test
+ public void testMultipleUserAgentsThrowsException() throws Exception {
+ RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
+ Exception exception = assertThrows(IllegalArgumentException.class, () -> {
+ Transport transport = new RestClientTransport(restClient, null,
+ RequestOptions.DEFAULT.toBuilder().addHeader("User-Agent", CUSTOM_USER_AGENT).build(),
+ new UserAgent(CUSTOM_NAME_2, CUSTOM_VERSION_2));
+ });
+ }
+
+}