| /* |
| * 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.slider.client; |
| |
| import com.google.common.base.Preconditions; |
| import org.apache.hadoop.fs.PathNotFoundException; |
| import org.apache.hadoop.registry.client.api.RegistryConstants; |
| import org.apache.hadoop.registry.client.api.RegistryOperations; |
| import org.apache.hadoop.registry.client.binding.RegistryPathUtils; |
| import org.apache.hadoop.registry.client.binding.RegistryTypeUtils; |
| import org.apache.hadoop.registry.client.exceptions.InvalidRecordException; |
| import org.apache.hadoop.registry.client.impl.zk.RegistryInternalConstants; |
| import org.apache.hadoop.registry.client.types.Endpoint; |
| import org.apache.hadoop.registry.client.types.ServiceRecord; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.io.IOException; |
| import java.util.List; |
| |
| import static org.apache.hadoop.registry.client.binding.RegistryPathUtils.encodeForRegistry; |
| import static org.apache.hadoop.registry.client.binding.RegistryUtils.convertUsername; |
| import static org.apache.hadoop.registry.client.binding.RegistryUtils.getCurrentUsernameUnencoded; |
| import static org.apache.hadoop.registry.client.binding.RegistryUtils.servicePath; |
| |
| /** |
| * Generic code to get the URLs for clients via the registry |
| */ |
| public class ClientRegistryBinder { |
| private static final Logger log = |
| LoggerFactory.getLogger(ClientRegistryBinder.class); |
| |
| private final RegistryOperations operations; |
| |
| public ClientRegistryBinder(RegistryOperations operations) { |
| this.operations = operations; |
| } |
| |
| /** |
| * Buld the user path -switches to the system path if the user is "". |
| * It also cross-converts the username to ascii via punycode |
| * @param username username or "" |
| * @return the path to the user |
| */ |
| public static String homePathForUser(String username) { |
| Preconditions.checkArgument(username != null, "null user"); |
| |
| // catch recursion |
| if (username.startsWith(RegistryConstants.PATH_USERS)) { |
| return username; |
| } |
| |
| if (username.isEmpty()) { |
| return RegistryConstants.PATH_SYSTEM_SERVICES; |
| } |
| |
| // convert username to registry name |
| String convertedName = convertUsername(username); |
| |
| return RegistryPathUtils.join(RegistryConstants.PATH_USERS, |
| encodeForRegistry(convertedName)); |
| } |
| |
| /** |
| * Get the current username, before any encoding has been applied. |
| * @return the current user from the kerberos identity, falling back |
| * to the user and/or env variables. |
| */ |
| public static String currentUsernameUnencoded() { |
| String env_hadoop_username = System.getenv( |
| RegistryInternalConstants.HADOOP_USER_NAME); |
| return getCurrentUsernameUnencoded(env_hadoop_username); |
| } |
| |
| /** |
| * Qualify a user. |
| * <ol> |
| * <li> <code>"~"</code> maps to user home path home</li> |
| * <li> <code>"~user"</code> maps to <code>/users/$user</code></li> |
| * <li> <code>"/"</code> maps to <code>/services/</code></li> |
| * </ol> |
| * @param user the username |
| * @return the base path |
| */ |
| public static String qualifyUser(String user) { |
| // qualify the user |
| String t = user.trim(); |
| if (t.startsWith("/")) { |
| // already resolved |
| return t; |
| } else if (t.equals("~")) { |
| // self |
| return currentUsernameUnencoded(); |
| } else if (t.startsWith("~")) { |
| // another user |
| // convert username to registry name |
| String convertedName = convertUsername(t.substring(1)); |
| |
| return RegistryPathUtils.join(RegistryConstants.PATH_USERS, |
| encodeForRegistry(convertedName)); |
| } else { |
| return "/" + t; |
| } |
| } |
| |
| /** |
| * Look up an external REST API |
| * @param user user which will be qualified as per {@link #qualifyUser(String)} |
| * @param serviceClass service class |
| * @param instance instance name |
| * @param api API |
| * @return the API, or an exception is raised. |
| * @throws IOException |
| */ |
| public String lookupExternalRestAPI(String user, |
| String serviceClass, |
| String instance, |
| String api) |
| throws IOException { |
| String qualified = qualifyUser(user); |
| String path = servicePath(qualified, serviceClass, instance); |
| String restAPI = resolveExternalRestAPI(api, path); |
| if (restAPI == null) { |
| throw new PathNotFoundException(path + " API " + api); |
| } |
| return restAPI; |
| } |
| |
| /** |
| * Resolve a service record then return an external REST API exported it. |
| * |
| * @param api API to resolve |
| * @param path path of the service record |
| * @return null if the record exists but the API is absent or it has no |
| * REST endpoints. |
| * @throws IOException resolution problems, as covered in |
| * {@link RegistryOperations#resolve(String)} |
| */ |
| protected String resolveExternalRestAPI(String api, String path) throws |
| IOException { |
| ServiceRecord record = operations.resolve(path); |
| return lookupRestAPI(record, api, true); |
| } |
| |
| /** |
| * Look up an external REST API endpoint |
| * @param record service record |
| * @param api URI of api |
| * @param external flag to indicate this is an external record |
| * @return the first endpoint of the implementation, or null if there |
| * is no entry for the API, implementation or it's the wrong type. |
| */ |
| public static String lookupRestAPI(ServiceRecord record, |
| String api, boolean external) throws InvalidRecordException { |
| try { |
| String url = null; |
| Endpoint endpoint = getEndpoint(record, api, external); |
| List<String> addresses = |
| RegistryTypeUtils.retrieveAddressesUriType(endpoint); |
| if (addresses != null && !addresses.isEmpty()) { |
| url = addresses.get(0); |
| } |
| return url; |
| } catch (InvalidRecordException e) { |
| log.debug("looking for API {}", api, e); |
| return null; |
| } |
| } |
| |
| /** |
| * Get an endpont by API |
| * @param record service record |
| * @param api API |
| * @param external flag to indicate this is an external record |
| * @return the endpoint or null |
| */ |
| public static Endpoint getEndpoint(ServiceRecord record, |
| String api, |
| boolean external) { |
| return external ? record.getExternalEndpoint(api) |
| : record.getInternalEndpoint(api); |
| } |
| |
| |
| } |