Merge branch 'es_remove_items' into 'master'

ES: Removing repository and wiki index after removing project

https://gitlab.com/gitlab-org/gitlab-ee/issues/299

https://gitlab.com/gitlab-org/gitlab-ee/issues/209


cc @jnijhof @jacobvosmaer 

@axil I've touched documentation here. Please take a look. 

See merge request !205

CHANGELOG-EE

 Please view this file on the master branch, on stable branches it's out of date.
-
 v 8.6.0 (unreleased)
   - Improve weight filter for issues
   - [Elastic] Add elastic checker to gitlab:check
   - [Elastic] Added UPDATE_INDEX option to rake task
+  - [Elasticsearch] Removing repository and wiki index after removing project
 
 v 8.5.1
   - Fix adding pages domain to projects in groups

app/workers/elastic_indexer_worker.rb

@@ -6,16 +6,43 @@ class ElasticIndexerWorker
   Client = Elasticsearch::Client.new(host: Gitlab.config.elasticsearch.host,
                                      port: Gitlab.config.elasticsearch.port)
 
-  def perform(operation, klass, record_id, options = {})
-    cklass = klass.constantize
+  def perform(operation, class_name, record_id, options = {})
+    klass = class_name.constantize
 
     case operation.to_s
     when /index|update/
-      record = cklass.find(record_id)
+      record = klass.find(record_id)
       record.__elasticsearch__.client = Client
       record.__elasticsearch__.__send__ "#{operation}_document"
     when /delete/
-      Client.delete index: cklass.index_name, type: cklass.document_type, id: record_id
+      Client.delete index: klass.index_name, type: klass.document_type, id: record_id
+
+      clear_project_indexes(record_id) if klass == Project
+    end
   end
+
+  def clear_project_indexes(record_id)
+    # Remove repository index
+    Client.delete_by_query({
+      index: Repository.__elasticsearch__.index_name,
+      body: {
+        query: {
+          or: [
+            { term: { "commit.rid" => record_id } },
+            { term: { "blob.rid" => record_id } }
+          ]
+        }
+      }
+    })
+
+    # Remove wiki index
+    Client.delete_by_query({
+      index: ProjectWiki.__elasticsearch__.index_name,
+      body: {
+        query: {
+          term: { "blob.rid" => "wiki_#{record_id}" }
+        }
+      }
+    })
   end
 end

doc/integration/elasticsearch.md

@@ -31,7 +31,7 @@ is installed or on a separate server.
 These are the minimum requirements needed for Elasticsearch to work:
 
 - GitLab 8.4+
-- Elasticsearch 2.0+
+- Elasticsearch 2.0+ (with [Delete By Query Plugin](https://www.elastic.co/guide/en/elasticsearch/plugins/2.0/plugins-delete-by-query.html) installed)
 
 ## Install Elasticsearch