title: Zeppelin won't start with SSL enabled
body: <p>I'm using Ambari 2.4.0.1 with HDP 2.5 and trying to configure Zeppelin to use SSL.  When I set the zeppelin.ssl property to "true" I always get this error when starting the server:</p>
  
  <pre><code>ERROR [2017-01-24 02:13:43,456] ({main} ZeppelinServer.java[main]:118) - Error while running jettyServer
  java.io.FileNotFoundException: /etc/zeppelin/2.5.3.0-37/0/null (No such file or directory)
          at java.io.FileInputStream.open0(Native Method)
          at java.io.FileInputStream.open(FileInputStream.java:195)
          at java.io.FileInputStream.&lt;init&gt;(FileInputStream.java:138)
          at org.eclipse.jetty.util.resource.FileResource.getInputStream(FileResource.java:290)
          at org.eclipse.jetty.util.security.CertificateUtils.getKeyStore(CertificateUtils.java:43)
          at org.eclipse.jetty.util.ssl.SslContextFactory.loadKeyStore(SslContextFactory.java:871)
          at org.eclipse.jetty.util.ssl.SslContextFactory.doStart(SslContextFactory.java:273)
          at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
          at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
          at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
          at org.eclipse.jetty.server.SslConnectionFactory.doStart(SslConnectionFactory.java:64)
          at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
          at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
          at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
          at org.eclipse.jetty.server.AbstractConnector.doStart(AbstractConnector.java:256)
          at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:81)
          at org.eclipse.jetty.server.ServerConnector.doStart(ServerConnector.java:236)
          at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
          at org.eclipse.jetty.server.Server.doStart(Server.java:366)
          at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
          at org.apache.zeppelin.server.ZeppelinServer.main(ZeppelinServer.java:116)
  </code></pre>
  
  <p>I have no idea what file it's trying to look for in /etc/zeppelin/2.5.3.0-37/0/</p>
  
  <p>The zeppelin.ssl.keystore.path is set to conf/keystore and the keystore file is at that location.  It's a relative path under /usr/hdp/current/zeppelin-server, and the conf dir there is actually a symlink to /etc/zeppelin/2.5.3.0-37/0/</p>
  
  <p>I have client auth set to false, but set the truststore path nonetheless, and that didn't seem to make any difference.  </p>
  
  <p>If I toggle the zeppelin.ssl setting to "false" the server starts normally.</p>
  
  <p>Any thoughts on what could be going on?</p>