Simple View Example

Description

The Simple View is an example of a basic REST service that serves the configuration parameter value, and a single HTML page that shows the value. It demonstrates the very basics of how to write and expose a REST service which works with instance parameters, and the basics of how to include UI assets with your view that access that service.

Package

All views are packaged as a view archive. The view archive contains the configuration file and various optional components of the view.

#####view.xml

The view.xml file is the only required file for a view archive. The view.xml is the configuration that describes the view and view instances for Ambari. The view.xml for this example defines one required parameter for configuring a view instance: what.is.the.value. The view also defines a single resource that exposes a REST service at the /simple end point.

<view>
  <name>SIMPLE</name>
  <label>Simple</label>
  <version>0.1.0</version>
  <parameter>
    <name>what.is.the.value</name>
    <description>Provide a configuration value</description>
    <required>true</required>
  </parameter>
  <resource>
    <name>simple</name>
    <service-class>org.apache.ambari.view.simple.SimpleService</service-class>
  </resource>
</view>

Build

The view can be built as a maven project.

cd ambari-views/examples/simple-view
mvn clean package

The build will produce the view archive.

ambari-views/examples/simple-view/target/simple-view-0.1.0.jar

Place the view archive on the Ambari Server and restart to deploy.

cp simple-view-0.1.0.jar /var/lib/ambari-server/resources/views/
ambari-server restart

Create View Instance

With the view deployed, create an instance of the view to be used by Ambari users.

POST
/api/v1/views/SIMPLE/versions/0.1.0/instances/SIMPLE_1

[ {
  "ViewInstanceInfo" : {
    "label" : "Simple 1",
    "description" : "Enter a configuration value",
    "properties" : {
      "what.is.the.value" : "blue"
    }
  }
} ]

Access the view service end point:

/api/v1/views/SIMPLE/versions/0.1.0/instances/SIMPLE_1/resources/simple

Access the view UI:

/views/SIMPLE/0.1.0/SIMPLE_1