Site plugins used to be used for things like kibana and marvel, but
there is no longer a need since kibana (and marvel as a kibana plugin)
uses node.js. This change removes site plugins, as well as the flag for
jvm plugins. Now all plugins are jvm plugins.
This fixes the `lenient` parameter to be `missingClasses`. I will remove this boolean and we can handle them via the normal whitelist.
It also adds a check for sheisty classes (jar hell with the jdk).
This is inspired by the lucene "sheisty" classes check, but it has false positives. This check is more evil, it validates every class file against the extension classloader as a resource, to see if it exists there. If so: jar hell.
This jar hell is a problem for several reasons:
1. causes insanely-hard-to-debug problems (like bugs in forbidden-apis)
2. hides problems (like internal api access)
3. the code you think is executing, is not really executing
4. security permissions are not what you think they are
5. brings in unnecessary dependencies
6. its jar hell
The more difficult problems are stuff like jython, where these classes are simply 'uberjared' directly in, so you cant just fix them by removing a bogus dependency. And there is a legit reason for them to do that, they want to support java 1.4.
Migrated from ES-Hadoop. Contains several improvements regarding:
* Security
Takes advantage of the pluggable security in ES 2.2 and uses that in order
to grant the necessary permissions to the Hadoop libs. It relies on a
dedicated DomainCombiner to grant permissions only when needed only to the
libraries installed in the plugin folder
Add security checks for SpecialPermission/scripting and provides out of
the box permissions for the latest Hadoop 1.x (1.2.1) and 2.x (2.7.1)
* Testing
Uses a customized Local FS to perform actual integration testing of the
Hadoop stack (and thus to make sure the proper permissions and ACC blocks
are in place) however without requiring extra permissions for testing.
If needed, a MiniDFS cluster is provided (though it requires extra
permissions to bind ports)
Provides a RestIT test
* Build system
Picks the build system used in ES (still Gradle)