001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase;
019
020import java.io.IOException;
021import java.util.concurrent.CompletableFuture;
022import org.apache.hadoop.conf.Configuration;
023import org.apache.hadoop.hbase.client.AsyncConnection;
024import org.apache.hadoop.hbase.client.ConnectionFactory;
025import org.junit.ClassRule;
026import org.junit.Rule;
027import org.junit.rules.ExternalResource;
028import org.junit.rules.TestRule;
029
030/**
031 * A {@link TestRule} that manages an instance of the {@link MiniHBaseCluster}. Can be used in
032 * either the {@link Rule} or {@link ClassRule} positions. Built on top of an instance of
033 * {@link HBaseTestingUtility}, so be weary of intermixing direct use of that class with this Rule.
034 * </p>
035 * Use in combination with {@link ConnectionRule}, for example:
036 *
037 * <pre>{@code
038 *   public class TestMyClass {
039 *     @ClassRule
040 *     public static final MiniClusterRule miniClusterRule = MiniClusterRule.newBuilder().build();
041 *
042 *     @Rule
043 *     public final ConnectionRule connectionRule =
044 *       new ConnectionRule(miniClusterRule::createConnection);
045 *   }
046 * }</pre>
047 */
048public final class MiniClusterRule extends ExternalResource {
049
050  /**
051   * A builder for fluent composition of a new {@link MiniClusterRule}.
052   */
053  public static class Builder {
054
055    private StartMiniClusterOption miniClusterOption;
056    private Configuration conf;
057
058    /**
059     * Use the provided {@link StartMiniClusterOption} to construct the {@link MiniHBaseCluster}.
060     */
061    public Builder setMiniClusterOption(final StartMiniClusterOption miniClusterOption) {
062      this.miniClusterOption = miniClusterOption;
063      return this;
064    }
065
066    /**
067     * Seed the underlying {@link HBaseTestingUtility} with the provided {@link Configuration}.
068     */
069    public Builder setConfiguration(final Configuration conf) {
070      this.conf = conf;
071      return this;
072    }
073
074    public MiniClusterRule build() {
075      return new MiniClusterRule(
076        conf,
077        miniClusterOption != null
078          ? miniClusterOption
079          : StartMiniClusterOption.builder().build());
080    }
081  }
082
083  private final HBaseTestingUtility testingUtility;
084  private final StartMiniClusterOption miniClusterOptions;
085
086  private MiniHBaseCluster miniCluster;
087
088  private MiniClusterRule(final Configuration conf,
089    final StartMiniClusterOption miniClusterOptions) {
090    this.testingUtility = new HBaseTestingUtility(conf);
091    this.miniClusterOptions = miniClusterOptions;
092  }
093
094  public static Builder newBuilder() {
095    return new Builder();
096  }
097
098  /**
099   * @return the underlying instance of {@link HBaseTestingUtility}
100   */
101  public HBaseTestingUtility getTestingUtility() {
102    return testingUtility;
103  }
104
105  /**
106   * Create a {@link AsyncConnection} to the managed {@link MiniHBaseCluster}. It's up to the caller
107   * to {@link AsyncConnection#close() close()} the connection when finished.
108   */
109  public CompletableFuture<AsyncConnection> createConnection() {
110    if (miniCluster == null) {
111      throw new IllegalStateException("test cluster not initialized");
112    }
113    return ConnectionFactory.createAsyncConnection(miniCluster.getConf());
114  }
115
116  @Override
117  protected void before() throws Throwable {
118    miniCluster = testingUtility.startMiniCluster(miniClusterOptions);
119  }
120
121  @Override
122  protected void after() {
123    try {
124      testingUtility.shutdownMiniCluster();
125    } catch (IOException e) {
126      throw new RuntimeException(e);
127    }
128  }
129}