[FLINK-3023][web-dashboard] Display version and commit information on Overview Page.

This closes #1422

flink-runtime-web/src/main/java/org/apache/flink/runtime/webmonitor/handlers/ClusterOverviewHandler.java

@@ -22,6 +22,7 @@ import com.fasterxml.jackson.core.JsonGenerator;
 import org.apache.flink.runtime.instance.ActorGateway;
 import org.apache.flink.runtime.messages.webmonitor.RequestStatusOverview;
 import org.apache.flink.runtime.messages.webmonitor.StatusOverview;
+import org.apache.flink.runtime.util.EnvironmentInformation;
 import scala.concurrent.Await;
 import scala.concurrent.Future;
 import scala.concurrent.duration.FiniteDuration;
@@ -38,7 +39,10 @@ import static com.google.common.base.Preconditions.checkNotNull;
 public class ClusterOverviewHandler implements RequestHandler, RequestHandler.JsonResponse {
 
 	private final FiniteDuration timeout;
-	
+
+	private static final String version = EnvironmentInformation.getVersion();
+
+	private static final String commitID = EnvironmentInformation.getRevisionInformation().commitId;
 
 	public ClusterOverviewHandler(FiniteDuration timeout) {
 		this.timeout = checkNotNull(timeout);
@@ -63,6 +67,10 @@ public class ClusterOverviewHandler implements RequestHandler, RequestHandler.Js
 				gen.writeNumberField("jobs-finished", overview.getNumJobsFinished());
 				gen.writeNumberField("jobs-cancelled", overview.getNumJobsCancelled());
 				gen.writeNumberField("jobs-failed", overview.getNumJobsFailed());
+				gen.writeStringField("flink-version", version);
+				if (!commitID.equals(EnvironmentInformation.UNKNOWN)) {
+					gen.writeStringField("flink-commit", commitID);
+				}
 				gen.writeEndObject();
 
 				gen.close();

flink-runtime-web/web-dashboard/app/partials/overview.jade

@@ -22,6 +22,12 @@ nav.navbar.navbar-default.navbar-fixed-top.navbar-main
   .navbar-title
     | Overview
 
+  .navbar-info.last.first
+    | Version: {{overview['flink-version']}}
+
+  .navbar-info.last.first(ng-if="overview['flink-commit']")
+    | Commit: {{overview['flink-commit']}}
+
 #content-inner
   .row
     .col-md-6

flink-runtime-web/web-dashboard/web/partials/overview.html

@@ -20,6 +20,8 @@ limitations under the License.
 <nav class="navbar navbar-default navbar-fixed-top navbar-main">
   <div id="fold-button" ng-click="showSidebar()" class="btn btn-default navbar-btn pull-left"><i class="fa fa-navicon"></i></div>
   <div class="navbar-title">Overview</div>
+  <div class="navbar-info last first">Version: {{overview['flink-version']}}</div>
+  <div ng-if="overview['flink-commit']" class="navbar-info last first">Commit: {{overview['flink-commit']}}</div>
 </nav>
 <div id="content-inner">
   <div class="row">

flink-runtime/src/main/java/org/apache/flink/runtime/util/EnvironmentInformation.java

@@ -39,7 +39,7 @@ public class EnvironmentInformation {
 
 	private static final Logger LOG = LoggerFactory.getLogger(EnvironmentInformation.class);
 
-	private static final String UNKNOWN = "<unknown>";
+	public static final String UNKNOWN = "<unknown>";
 
 	/**
 	 * Returns the version of the code as String. If version == null, then the JobManager does not run from a