Embedded Consul

Embedded Consul provides easy way to run Consul in integration tests.

Built on Consul 1.4.2
Compatible with jdk1.8+.
Working on all operating systems: Mac, Linux, Windows.

How to get it?

    <dependency>
      <groupId>com.pszymczyk.consul</groupId>
      <artifactId>embedded-consul</artifactId>
      <version>2.1.4</version>
      <scope>test</scope>
    </dependency>

    testImplementation 'com.pszymczyk.consul:embedded-consul:2.1.4'

Usage

Spring Boot setup

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringBootIntegrationTest {

    @BeforeClass
    public static void setup() {
        consul = ConsulStarterBuilder.consulStarter().buildAndStart();

        System.setProperty("spring.cloud.consul.enabled", "true");
        System.setProperty("spring.cloud.consul.host", "localhost");
        System.setProperty("spring.cloud.consul.port", String.valueOf(consul.getHttpPort()));
    }

    @Test
    public void doSomethingWithSpring(){
        //use your spring beans
    }    
}

JUnit Rule

If JUnit is on classpath, simplest way to use embedded-consul is via JUnit rules.

public class IntegrationTest {

    @ClassRule
    public static final ConsulResource consul = new ConsulResource();

    private OkHttpClient client = new OkHttpClient();

    @Test
    public void shouldStartConsul() throws Throwable {
        await().atMost(30, TimeUnit.SECONDS).until(() -> {
            Request request = new Request.Builder()
                    .url("http://localhost:" + consul.getHttpPort() + "/v1/agent/self")
                    .build();

            return client.newCall(request).execute().code() == 200;
        });
    }
}

JUnit 5 Extension

There is also an extension for JUnit 5. Unlike in Junit 4 with @Rule and @ClassRule there is no option to control the scope of ConsulProcess. ConsulExtension starts Consul for a whole class just like @ClassRule, but it resets the Consul state between tests.

class IntegrationTest {

    @RegisterExtension
    ConsulExtension consul = new ConsulExtension();

    private OkHttpClient client = new OkHttpClient();

    @Test
    void shouldStartConsul() throws Throwable {
        await().atMost(30, TimeUnit.SECONDS).until(() -> {
            Request request = new Request.Builder()
                    .url("http://localhost:" + consul.getHttpPort() + "/v1/agent/self")
                    .build();

            return client.newCall(request).execute().code() == 200;
        });
    }
}

The extension can also be registered via @ExtendWith annotation and provided to test as a method argument.

@ExtendWith(ConsulExtension.class)
class IntegrationTest {

    @Test
    void test(ConsulProcess consul) {
        OkHttpClient client = new OkHttpClient();
        await().atMost(30, TimeUnit.SECONDS).until(() -> {
            Request request = new Request.Builder()
                    .url("http://localhost:" + consul.getHttpPort() + "/v1/agent/self")
                    .build();

            return client.newCall(request).execute().code() == 200;
        });
    }
}

Manual

public class IntegrationTest {

    private ConsulProcess consul;

    @Before
    public void setup() {
        consul = ConsulStarterBuilder.consulStarter().buildAndStart();
    }

    @After
    public void cleanup() throws Exception {
        consul.close();
    }

    /* tests as in example above */

Register Services

You can automatically register Services in Consul via ConsulStarterBuilder.

    
    ConsulStarterBuilder.consulStarter()
        .withService(
                new Service("a service"), 
                new Service("another service", "127.0.0.1", 8000));
        .buildAndStart();

Reset Consul state

The ConsulProcess can be reset at any time. Reset method do few operations:

• removing all registered services
• removes all registered checks
• removes all data from kv store
• destroy all active sessions

Invoking reset method is faster than starting new Consul process.

    consulClient.setKVBinaryValue("foo", "bar".getBytes())

    // do sth

    consul.reset()

    assert consulClient.getKVBinaryValue("foo").getValue() == null

Passing custom configuration

If you want to pass custom property which is not covered by ConsulStartrBuilder you can pass JSON configuration.

String customConfiguration =
                "{" +
                    "\"datacenter\": \"test-dc\"," +                    
                    "\"log_level\": \"INFO\"," +
                    "\"node_name\": \"foobar\"" +
                "}";

ConsulProcess consul = ConsulStarterBuilder.consulStarter().withCustomConfig(customConfiguration).buildAndStart();    

Given JSON configuration will be saved in addition configuration file extra_config.json and processed after base configuration (with highest priority).

Changing download directory

An environment variable can be set to change the consul CDN.

# default
export CONSUL_BINARY_CDN=https://releases.hashicorp.com/consul/

Proxy can be used if necessary.

https.proxyHost=localhost 
https.proxyPort=3128

Files structure

    ├─$temp-directory
    │ 
    ├── embedded-consul-$consul-version
    │   ├── consul
    │   └── consul.zip
    ├── embedded-consul-data-dir + randomNumber
    │   ├── raft
    │   │   ├── peers.json
    │   │   ├── raft.db
    │   │   └── snapshots
    │   └── serf
    │       ├── local.snapshot
    │       └── remote.snapshot
    ├── embedded-consul-config-dir + randomNumber
    │   ├── basic_config.json   
    │   └── extra_config.json

To avoid unnecessary downloads Consul binary is downloaded into static named directory /$tmp/embedded-consul-$consul-version. Another stuff (ports config, raft, serf) is created in dynamically named temp directories.

At the moment files are not deleted!.

Simultaneous running

Embedded Consul overrides all default ports used by Consul. Ports are randomized so it's possible to run multiple Consul Agents in single machine. Configuration file is stored in /$tmp/embedded-consul-config-dir$randomNumber/basic_config.json, sample content:

    {
        "ports": {
            "dns": 50084,
            "serf_lan": 50085,
            "serf_wan": 50086,
            "server": 50087
        },
        "disable_update_check": true,
        "performance": {
            "raft_multiplier": 1
        }
    }

JDK 1.7.x support

Support for older Java versions has been dropped throughout release 2.0.0. If you'd like to use embedded-consul with JDK 1.7 the 1.1.1 is the last appropriate version.