Riak Test Docker Framework

riak-test-docker is a test framework designed to manage docker-based Riak cluster for test environment.

Table of contents

• Preconditions
  • Additional environment configuration
• Using
  • Maven
  • Gradle
  • SBT
• Quick Example
• Creating and configuration cluster
  • System properties
• Seamless JUnit integration
  • @OverrideRiakClusterConfig annotation
  • Disabling rule

Preconditions

For using riak-test-docker framework, Docker must be installed and properly configured.

Additional environment configuration

Because of specific of using Docker on MacOS and Windows in current Docker implementation, before using riak-test-docker following environment variables must be configured:

• DOCKER_HOST="tcp://<Docker Host IP>:2376
• DOCKER_CERT_PATH=<path to Docker cert>

Tip: For MacOS following command must be used to configure Docker emvironment properly: docker-machine env. It will set all nessessary environment variables

The second thing which is must be configured for MacOS and Windows operating systems is static route:

• for MacOS: sudo route -n add 172.17.0.0/16 <Docker Host IP>
• for Windows: route ADD 172.17.0.0 MASK 255.255.0.0 <Docker Host IP>

Using

Include the artifact into your project using Gradle, Maven or SBT.

Make sure you've added the Basho Bintray repo by going here https://bintray.com/basho/data-platform and clicking the blue "SET ME UP!" button on the right of the page.

Maven

<dependency>
  <groupId>com.basho.riak.test</groupId>
  <artifactId>riak-test-docker</artifactId>
  <version>1.0-SNAPSHOT</version>
  <scope>test</scope>
</dependency>

Gradle

ext {
  riakTestDockerVersion = '1.0-SNAPSHOT'
}

dependencies {
  testCompile "com.basho.riak.test:riak-test-docker:$riakTestDockerVersion"
}

SBT

libraryDependencies ++= {
  val riakTestDockerVersion = "1.0-SNAPSHOT"

  Seq(
    "com.basho.riak.test" % "riak-test-docker" % riakTestDockerVersion % "test"
  )
}

Quick Example

Before we go into details of how to configure and use riak-test-docker in your tests, let's take a quick look at simple example.

  @Test
  public void testCluster() {
      final int nodes = 3;
      DockerRiakCluster riakCluster = new DockerRiakCluster(nodes, 3); // create new instance
      try {
          riakCluster.start(); // start cluster
          assertEquals(nodes, riakCluster.getIps().size());

          // process some logic
          final CoveragePlan.Response response = RiakTestUtils
                  .receiveCoveragePlan(String.join(",", riakCluster.getIps()));
          assertEquals(nodes, response.hosts().size());
          assertEquals(riakCluster.getIps(),
                  response.hosts().stream().map(HostAndPort::getHost).collect(Collectors.toSet()));
      } finally {
          riakCluster.stop(); // stop cluster
      }
  }

This test method illustrates the simpliest use-case of riak-test-docker framework. Basically it consists only of 3 steps:

1. Create new instance of DockerRiakCluster
2. Start cluster
3. Connect to started cluster using com.basho.riak.test.cluster.DockerRiakCluster#getIps method which provides an access to IP addresses of started Riak nodes.
4. When cluster is not nessessary anymore it's required to stop it

Creating and configuration cluster

By default DockerRiakCluster instance is ready to use right after usual instance cteation, even without any additional configuration. But also there might be a need to edit default parameters. Following properties might be configured for dockerized Riak cluster:

To make process of creation and configuration of DockerRiakCluster more flexible and simple, special builder was introduced: com.basho.riak.test.cluster.DockerRiakCluster.Builder. It contains methods which allow to set all properties listed earlier. The example of it's usage is shown below:

  DockerRiakCluster riakCluster = DockerRiakCluster.builder()
    .withNodes(2)
    .withTimeout(3)
    .withImageName("basho/riak-ts:1.3.0")
    .withBucketType("plain", Collections.emptyMap())
    .build();

Note: the usage of cluster builder is strongly recommended in most cases, because constructor-based approach could decreace code redability and quality.

System properties

Following system properties could be used to override cluster configuration globally:

If these properties are specified their analogs in builder configuration will be ignored.

Seamless JUnit integration

riak-test-docker provides a JUnit @Rule implementation that manages an ad-hoc dockerized Riak cluster that makes testing applications that use Riak really easy.

Create a test in the normal way. The only difference with using riak-test-docker is to add either a @ClassRule or a @Rule in your test on an instance of com.basho.riak.test.rule.DockerRiakClusterRule.

The following creates a static @ClassRule which will be invoked once at initialization of the test class and will then be cleaned up after all the tests are run. It will not destroy and re-create the cluster after each test (you'd use a normal @Rule for that).

  @ClassRule
  public static DockerRiakClusterRule riakCluster = new DockerRiakClusterRule(
          DockerRiakCluster.builder()
            .withImageName("basho/riak-ts:1.3.0")
            .withNodes(2)
            .withTimeout(2));

@OverrideRiakClusterConfig annotation

Often test classes are built according to some class hierarchy. Usually this happens when developers don't want to duplicate a configuration code which is common for most of test classes and keep it in some base class. In such situation DockerRiakClusterRule could be also declared as a static field (@ClassRule) in that base class to avoid keeping it in each test class. Such approach is reasonable until all your tests require identical cluster configuration. But if, for example, there is a need to increase number of nodes for particular class without changing other common logic, it could be a real problem, because in this case you have to totally duplicate logic of base class inside current or increase a level of class hierarhy and create additional middle layer if base test classes.

To solve such difficulties beforehand, the @com.basho.riak.test.rule.annotations.OverrideRiakClusterConfig annotation was introduced. It allows to override amount of nodes and starting timeout for particular class:

  @OverrideRiakClusterConfig(nodes = 3, timeout = 3) // override class configuration
  public class DockerRiakClusterClassRuleTest {

      @ClassRule
      public static DockerRiakClusterRule riakCluster = new DockerRiakClusterRule(
              DockerRiakCluster.builder().withTimeout(3)); // create cluster with 1 node

      @Test
      public void testCluster() {
          /* passes, despite the fact DockerRiakClusterRule was configured to have only one node,
             due to present @OverrideRiakClusterConfig annotation */
          assertEquals(3, riakCluster.getIps().size());
      }
  }

Described behavior also works for non-static @Rule. We can change amount of Riak nodes for particular test method by annotating it with @OverrideRiakClusterConfig annotation, even if test class contains non-static rule which will configure and start Riak cluster for each test method.

@Rule
public DockerRiakClusterRule riakCluster = new DockerRiakClusterRule(
        DockerRiakCluster.builder().withNodes(3).withTimeout(3)); // create cluster with 3 nodes

@Test
@OverrideRiakClusterConfig(nodes = 1, timeout = 1)
public void testClusterWithOverriddenNodesCount(){
    /* passes, despite the fact DockerRiakClusterRule was configured to have three nodes,
       due to present @OverrideRiakClusterConfig annotation */
    assertEquals(1, riakCluster.getIps().size());
}

Disabling rule

DockerRiakClusterRule can be totally disabled using special constructor parameter:

@ClassRule
public static DockerRiakClusterRule riakCluster = new DockerRiakClusterRule(
        DockerRiakCluster.builder().withTimeout(3), true);

If this addional parameter is set true, than docker cluster wont be started at all and com.basho.riak.test.rule.DockerRiakClusterRule#getIps will return empty set

This feature might be helpful if there is a need to disable rule according to some condition (for example, disable if some system property configured)