Add jar hell check test for the shaded jar

core/src/main/java/org/elasticsearch/bootstrap/JarHell.java

@@ -47,8 +47,11 @@ import java.util.jar.Manifest;
 public class JarHell {
 
     /** Simple driver class, can be used eg. from builds. Returns non-zero on jar-hell */
+    @SuppressForbidden(reason = "command line tool")
     public static void main(String args[]) throws Exception {
+        System.out.println("checking for jar hell...");
         checkJarHell();
+        System.out.println("no jar hell found");
     }
 
     /**

dev-tools/src/main/resources/ant/integration-tests.xml

@@ -276,4 +276,14 @@
     <startup-elasticsearch home="${integ.scratch}/rpm-extracted/usr/share/elasticsearch/"/>
   </target>
 
+  <!-- check shaded jar for jar hell -->
+  <target name="check-for-jar-hell">
+    <java failonerror="true" fork="true" classname="org.elasticsearch.bootstrap.JarHell">
+        <classpath>
+           <pathelement location="${project.build.directory}/${project.artifactId}-${project.version}.jar"/>
+           <pathelement location="${org.apache.lucene:lucene-core:jar}"/>
+        </classpath>
+    </java>
+  </target>
+
 </project>

distribution/shaded/pom.xml

@@ -38,6 +38,24 @@
         </plugins>
         <pluginManagement>
             <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-antrun-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>check-for-jar-hell</id>
+                        <phase>integration-test</phase>
+                        <goals>
+                          <goal>run</goal>
+                        </goals>
+                        <configuration>
+                            <target>
+                                <ant antfile="${elasticsearch.integ.antfile}" target="check-for-jar-hell"/>
+                            </target>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-shade-plugin</artifactId>