hbase-server/src/test/java/org/apache/hadoop/hbase/MiniClusterRule.java

   1 /*
   2  * Licensed to the Apache Software Foundation (ASF) under one
   3  * or more contributor license agreements.  See the NOTICE file
   4  * distributed with this work for additional information
   5  * regarding copyright ownership.  The ASF licenses this file
   6  * to you under the Apache License, Version 2.0 (the
   7  * "License"); you may not use this file except in compliance
   8  * with the License.  You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  */
  18 package org.apache.hadoop.hbase;
  19
  20 import java.io.IOException;
  21 import java.util.concurrent.CompletableFuture;
  22 import org.apache.hadoop.conf.Configuration;
  23 import org.apache.hadoop.hbase.client.AsyncConnection;
  24 import org.apache.hadoop.hbase.client.ConnectionFactory;
  25 import org.junit.ClassRule;
  26 import org.junit.Rule;
  27 import org.junit.rules.ExternalResource;
  28 import org.junit.rules.TestRule;
  29
  30 /**
  31  * A {@link TestRule} that manages an instance of the {@link SingleProcessHBaseCluster}. Can be used
  32  * in either the {@link Rule} or {@link ClassRule} positions. Built on top of an instance of
  33  * {@link HBaseTestingUtil}, so be weary of intermixing direct use of that class with this Rule.
  34  * </p>
  35  * Use in combination with {@link ConnectionRule}, for example:
  36  *
  37  * <pre>
  38  * {
  39  *   &#64;code
  40  *   public class TestMyClass {
  41  *     &#64;ClassRule
  42  *     public static final MiniClusterRule miniClusterRule = MiniClusterRule.newBuilder().build();
  43  *
  44  *     &#64;Rule
  45  *     public final ConnectionRule connectionRule =
  46  *       new ConnectionRule(miniClusterRule::createConnection);
  47  *   }
  48  * }
  49  * </pre>
  50  */
  51 public final class MiniClusterRule extends ExternalResource {
  52
  53   /**
  54    * A builder for fluent composition of a new {@link MiniClusterRule}.
  55    */
  56   public static class Builder {
  57
  58     private StartTestingClusterOption miniClusterOption;
  59     private Configuration conf;
  60
  61     /**
  62      * Use the provided {@link StartTestingClusterOption} to construct the
  63      * {@link SingleProcessHBaseCluster}.
  64      */
  65     public Builder setMiniClusterOption(final StartTestingClusterOption miniClusterOption) {
  66       this.miniClusterOption = miniClusterOption;
  67       return this;
  68     }
  69
  70     /**
  71      * Seed the underlying {@link HBaseTestingUtil} with the provided {@link Configuration}.
  72      */
  73     public Builder setConfiguration(final Configuration conf) {
  74       this.conf = conf;
  75       return this;
  76     }
  77
  78     public MiniClusterRule build() {
  79       return new MiniClusterRule(conf, miniClusterOption != null ? miniClusterOption :
  80         StartTestingClusterOption.builder().build());
  81     }
  82   }
  83
  84   private final HBaseTestingUtil testingUtility;
  85   private final StartTestingClusterOption miniClusterOptions;
  86
  87   private SingleProcessHBaseCluster miniCluster;
  88
  89   private MiniClusterRule(final Configuration conf,
  90     final StartTestingClusterOption miniClusterOptions) {
  91     this.testingUtility = new HBaseTestingUtil(conf);
  92     this.miniClusterOptions = miniClusterOptions;
  93   }
  94
  95   public static Builder newBuilder() {
  96     return new Builder();
  97   }
  98
  99   /**
 100    * Returns the underlying instance of {@link HBaseTestingUtil}
 101    */
 102   public HBaseTestingUtil getTestingUtility() {
 103     return testingUtility;
 104   }
 105
 106   /**
 107    * Create a {@link AsyncConnection} to the managed {@link SingleProcessHBaseCluster}. It's up to
 108    * the caller to {@link AsyncConnection#close() close()} the connection when finished.
 109    */
 110   public CompletableFuture<AsyncConnection> createConnection() {
 111     if (miniCluster == null) {
 112       throw new IllegalStateException("test cluster not initialized");
 113     }
 114     return ConnectionFactory.createAsyncConnection(miniCluster.getConf());
 115   }
 116
 117   @Override
 118   protected void before() throws Throwable {
 119     miniCluster = testingUtility.startMiniCluster(miniClusterOptions);
 120   }
 121
 122   @Override
 123   protected void after() {
 124     try {
 125       testingUtility.shutdownMiniCluster();
 126     } catch (IOException e) {
 127       throw new RuntimeException(e);
 128     }
 129   }
 130 }