From d68a4ec82e69f2be23e95a58759b8bd956f04373 Mon Sep 17 00:00:00 2001
From: James Rodewig <james.rodewig@elastic.co>
Date: Tue, 11 Feb 2020 11:49:49 -0500
Subject: [PATCH] [7.x] Permit EQL feature flag in release builds (#52201)
 (#52214)

7.x backport of #52201

Provides a path to set register the EQL feature flag in release builds.
This enables EQL in release builds so that release docs tests pass.

Release docs tests do not have infrastructure in place to only register
snippets from included portions of the docs, they instead include all
docs snippets.

Since EQL can not be enabled in release builds, this meant that the EQL
snippets fail in the release docs tests.

This adds the ability to enable EQL in the release docs tests. This
system property will be removed when EQL is ready for release.
---
 docs/build.gradle                             |  5 ++---
 .../xpack/eql/plugin/EqlPlugin.java           | 20 ++++++++++++++++++-
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/docs/build.gradle b/docs/build.gradle
index 6ae649fe316..6f9ba9a2c0c 100644
--- a/docs/build.gradle
+++ b/docs/build.gradle
@@ -47,11 +47,10 @@ testClusters.integTest {
     setting 'indices.lifecycle.history_index_enabled', 'false'
     if (BuildParams.isSnapshotBuild() == false) {
       systemProperty 'es.autoscaling_feature_flag_registered', 'true'
+      systemProperty 'es.eql_feature_flag_registered', 'true'
     }
     setting 'xpack.autoscaling.enabled', 'true'
-    if (BuildParams.isSnapshotBuild()) {
-      setting 'xpack.eql.enabled', 'true'
-    }
+    setting 'xpack.eql.enabled', 'true'
   }
 
   // enable regexes in painless so our tests don't complain about example snippets that use them
diff --git a/x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/plugin/EqlPlugin.java b/x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/plugin/EqlPlugin.java
index 375789761d7..c6434ab4acf 100644
--- a/x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/plugin/EqlPlugin.java
+++ b/x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/plugin/EqlPlugin.java
@@ -45,6 +45,24 @@ import java.util.function.Supplier;
 
 public class EqlPlugin extends Plugin implements ActionPlugin {
 
+    private static final boolean EQL_FEATURE_FLAG_REGISTERED;
+
+    static {
+        final String property = System.getProperty("es.eql_feature_flag_registered");
+        if (Build.CURRENT.isSnapshot() && property != null) {
+            throw new IllegalArgumentException("es.eql_feature_flag_registered is only supported in non-snapshot builds");
+        }
+        if ("true".equals(property)) {
+            EQL_FEATURE_FLAG_REGISTERED = true;
+        } else if ("false".equals(property) || property == null) {
+            EQL_FEATURE_FLAG_REGISTERED = false;
+        } else {
+            throw new IllegalArgumentException(
+                "expected es.eql_feature_flag_registered to be unset or [true|false] but was [" + property + "]"
+            );
+        }
+    }
+
     public static final Setting<Boolean> EQL_ENABLED_SETTING = Setting.boolSetting(
         "xpack.eql.enabled",
         false,
@@ -87,7 +105,7 @@ public class EqlPlugin extends Plugin implements ActionPlugin {
      */
     @Override
     public List<Setting<?>> getSettings() {
-        if (isSnapshot()) {
+        if (isSnapshot() || EQL_FEATURE_FLAG_REGISTERED) {
             return Collections.singletonList(EQL_ENABLED_SETTING);
         } else {
             return Collections.emptyList();