Elasticsearch 5.1.x. Update requirements

doc/integration/elasticsearch.md

@@ -29,12 +29,7 @@ GitLab, or on a separate server.
 
 ## Requirements
 
-These are the requirements needed for Elasticsearch to work:
-
-- GitLab 8.4+
-- Elasticsearch 2.4.x (with [Delete By Query Plugin](https://www.elastic.co/guide/en/elasticsearch/plugins/2.4/plugins-delete-by-query.html) installed)
-
-Please note that we don't support Elasticsearch 5.x at this time.
+Elasticsearch 5.1.x.
 
 ## Install Elasticsearch
 

lib/tasks/gitlab/check.rake

@@ -1082,23 +1082,15 @@ namespace :gitlab do
     client = Elasticsearch::Client.new(host: ApplicationSetting.current.elasticsearch_host,
                                        port: ApplicationSetting.current.elasticsearch_port)
 
-    print "Elasticsearch version 2.4.x? ... "
+    print "Elasticsearch version 5.1.x? ... "
 
     version = Gitlab::VersionInfo.parse(client.info["version"]["number"])
 
-    if version.major == 2 && version.minor == 4
+    if version.major == 5 && version.minor == 1
       puts "yes (#{version})".color(:green)
     else
       puts "no, you have #{version}".color(:red)
     end
-
-    print "Elasticsearch has plugin delete-by-query installed? ... "
-
-    if client.cat.plugins.include?("delete-by-query")
-      puts "yes".color(:green)
-    else
-      puts "no".color(:red)
-    end
   end
 
   def check_gitlab_geo_node(node)