title: How to change master web ui port when starting spark in local mode
body: <p>I am using spark in local mode (<code>master = "local[*]"</code>, see code below). How can I change the master port from <code>8080</code> to something else (in this case I need to since <code>8080</code> is already occupied). And, since it is occupied, spark master seems just not to start its web ui.</p>
  
  <pre><code>        SparkConf conf = new SparkConf()
                  .setMaster("local[*]")
                  .setAppName("Local RESTWS ML");
          return SparkSession
                  .builder()
                  .config(conf)
                  .getOrCreate();
      }
  </code></pre>
  
  <p>I tried setting the <code>SPARK_MASTER_WEBUI_PORT</code> environment variable without success.</p>