### Docker Links bridge

This discovery bridge imports services from Docker Links into the Vert.x service discovery.

When you link a Docker container to another Docker container, Docker injects a set of environment variables. This bridge analyzes these environment variables and imports service record for each link. The service type is deduced from the `service.type` label. If not set, the service is imported as `unknown`. Only `http-endpoint` are supported for now.

As the links are created when the container starts, the imported records are created when the bridge starts and do not change afterwards.

#### Using the bridge

To use this Vert.x discovery bridge, add the following dependency to the dependencies section of your build descriptor:

- Maven (in your `pom.xml`):

    <dependency>
      <groupId>io.vertx</groupId>
      <artifactId>vertx-service-discovery-bridge-docker-links</artifactId>
      <version>3.4.2</version>
    </dependency>

- Gradle (in your `build.gradle` file):

    compile 'io.vertx:vertx-service-discovery-bridge-docker-links:3.4.2'

Then, when creating the service discovery, registers this bridge as follows:

    ServiceDiscovery.create(vertx).registerServiceImporter(new io.vertx.servicediscovery.docker.DockerLinksServiceImporter(), [:])

The bridge does not need any further configuration.