Merge branch '6.x' into ccr-6.x

* 6.x:
  Remove out-of-date projectile file
  Remove Gradle cheatsheet
  Fix reproduction info to point to Gradle wrapper
  Update platforms tests to use Gradle wrapper
  Update testing docs to reflect Gradle wrapper
  Update contributing docs to use the Gradle wrapper
  test: replaced try-catch statements with expectThrows(...)
  Add getWarmer and getTranslog method to NodeIndicesStats (#28092)
  fix doc mistake
  Added ASN support for Ingest GeoIP plugin.
  Fix global aggregation that requires breadth first and scores (#27942)

Author: jasontedor

.projectile

@@ -95,13 +95,17 @@ Contributing to the Elasticsearch codebase
 Elasticsearch uses the Gradle wrapper for its build. You can execute Gradle
 using the wrapper via the `gradlew` script in the root of the repository.
 
-Eclipse users can automatically configure their IDE: `gradle eclipse`
+We support development in the Eclipse and IntelliJ IDEs. For Eclipse, the
+minimum version that we support is [Eclipse Oxygen][eclipse] (version 4.7). For
+IntelliJ, the minimum version that we support is [IntelliJ 2017.2][intellij].
+
+Eclipse users can automatically configure their IDE: `./gradlew eclipse`
 then `File: Import: Existing Projects into Workspace`. Select the
 option `Search for nested projects`. Additionally you will want to
 ensure that Eclipse is using 2048m of heap by modifying `eclipse.ini`
 accordingly to avoid GC overhead errors.
 
-IntelliJ users can automatically configure their IDE: `gradle idea`
+IntelliJ users can automatically configure their IDE: `./gradlew idea`
 then `File->New Project From Existing Sources`. Point to the root of
 the source directory, select
 `Import project from external model->Gradle`, enable
@@ -119,7 +123,7 @@ restart of IDEA). For IDEA 2017.3 and above, in addition to the JVM option, you
 classpath](https://github.com/elastic/elasticsearch/issues/14348) if that is
 reported as a source of jar hell.
 
-To run an instance of elasticsearch from the source code run `gradle run`
+To run an instance of elasticsearch from the source code run `./gradlew run`
 
 The Elasticsearch codebase makes heavy use of Java `assert`s and the
 test runner requires that assertions be enabled within the JVM. This
@@ -147,15 +151,15 @@ To create a distribution from the source, simply run:
 
 ```sh
 cd elasticsearch/
-gradle assemble
+./gradlew assemble
 ```
 
 You will find the newly built packages under: `./distribution/(deb|rpm|tar|zip)/build/distributions/`.
 
 Before submitting your changes, run the test suite to make sure that nothing is broken, with:
 
 ```sh
-gradle check
+./gradlew check
 ```
 
 Contributing as part of a class
@@ -183,6 +187,6 @@ code review process because it wastes our time.
 * We don't have the capacity to absorb an entire class full of new contributors,
 especially when they are unlikely to become long time contributors.
 
-Finally, we require that you run `gradle check` before submitting a
+Finally, we require that you run `./gradlew check` before submitting a
 non-documentation contribution. This is mentioned above, but it is worth
 repeating in this section because it has come up in this context.

CONTRIBUTING.md

@@ -202,9 +202,9 @@ We have just covered a very small portion of what Elasticsearch is all about. Fo
 
 h3. Building from Source
 
-Elasticsearch uses "Gradle":https://gradle.org for its build system. You'll need to have at least version 3.3 of Gradle installed.
+Elasticsearch uses "Gradle":https://gradle.org for its build system.
 
-In order to create a distribution, simply run the @gradle assemble@ command in the cloned directory.
+In order to create a distribution, simply run the @./gradlew assemble@ command in the cloned directory.
 
 The distribution for each project will be created under the @build/distributions@ directory in that project.