title: Can I use Spark's REST API to get the version of Spark on the Workers
body: <p>I know I can get the version of Spark v2.2.1 that's running on Spark Master with this command:</p>
  
  <pre><code>http://&lt;spark-master&gt;:4040/api/v1/version
  </code></pre>
  
  <p>which will return something like </p>
  
  <pre><code>{
    "spark" : "2.2.1"
  }
  </code></pre>
  
  <p>However, I also want to check the version of Spark running on each Worker.  I know I can get a list of all Workers thusly:</p>
  
  <pre><code>http://&lt;spark-master&gt;:8080/json/
  </code></pre>
  
  <p>which will return a response similar to</p>
  
  <pre><code>{
      "url": "spark://&lt;spark-master&gt;:7077",
      "workers": [{
              "id": "worker-20180228071440-&lt;ip-address&gt;-7078",
              "host": "&lt;ip-address&gt;",
              "port": 7078,
              "webuiaddress": "http://&lt;ip-address&gt;:8081",
              "cores": 8,
              "coresused": 8,
              "coresfree": 0,
              "memory": 40960,
              "memoryused": 35875,
              "memoryfree": 5085,
              "state": "ALIVE",
              "lastheartbeat": 1519932580686
          }, ...
      ],
      "cores": 32,
      "coresused": 32,
      "memory": 163840,
      "memoryused": 143500,
      "activeapps": [{
              "starttime": 1519830260440,
              "id": "app-20180228070420-0000",
              "name": "&lt;spark-app-name&gt;",
              "user": "&lt;spark-app-user&gt;",
              "memoryperslave": 35875,
              "submitdate": "Wed Feb 28 07:04:20 PST 2018",
              "state": "RUNNING",
              "duration": 102328434
          }
      ],
      "completedapps": [],
      "activedrivers": [],
      "status": "ALIVE"
  }
  </code></pre>
  
  <p>I'd like to use that information to query each Spark Worker's version.  Is this possible?</p>