=== Consul backend
<p>
The service discovery has a plug-able backend using the `link:../../apidocs/io/vertx/servicediscovery/spi/ServiceDiscoveryBackend.html[ServiceDiscoveryBackend]` SPI. This is an implementation of the SPI based
on Consul.
<p>
==== Using the Consul backend
<p>
To use the Consul backend, add the following dependency to the _dependencies_ section of your build
descriptor:
<p>
* Maven (in your `pom.xml`):
<p>
[source,xml,subs="+attributes"]
----
<dependency>
<groupId>io.vertx</groupId>
<artifactId>vertx-service-discovery-backend-consul</artifactId>
<version>3.9.9</version>
</dependency>
----
<p>
* Gradle (in your `build.gradle` file):
<p>
[source,groovy,subs="+attributes"]
----
compile 'io.vertx:vertx-service-discovery-backend-consul:3.9.9'
----
<p>
Be aware that you can have only a single implementation of the SPI in your _classpath_. If none,
the default backend is used.
<p>
==== Configuration
<p>
The backend is based on the http://vertx.io/docs/vertx-consul-client/java[vertx-consul-client].
The configuration is the client configuration.
<p>
Here is an example:
<p>
[source,kotlin]
----
ServiceDiscovery.create(vertx, ServiceDiscoveryOptions(
  backendConfiguration = json {
    obj(
      "defaultHost" to "127.0.0.1",
      "dc" to "my-dc"
    )
  }))

----