Adding the new search engine abstraction (#13304)

* WIP

* Adding bleve to go modules

* WIP

* Adding missing files from searchengine implementation

* WIP

* WIP

* WIP

* WIP

* WIP

* WIP

* User and channel indexing and searches implemented

* Make bleve tests run with in-memory indexes

* Implement post index and deletion tests

* Initial commits for the search layer

* Removing unnecesary indexing

* WIP

* WIP

* More fixes for tests

* Adding the search layer

* Finishing the migration of searchers to the layer

* Removing unnecesary code

* Allowing multiple engines active at the same time

* WIP

* Add simple post search

* Print information when using bleve

* Adding some debugging to understand better how the searches are working

* Making more dynamic config of search engines

* Add post search basics

* Adding the Purge API endpoint

* Fixing bleve config updates

* Adding missed file

* Regenerating search engine mocks

* Adding missed v5 to modules imports

* fixing i18n

* Fixing some test around search engine

* Removing all bleve traces

* Cleaning up the vendors directory and go.mod/go.sum files

* Regenerating timer layer

* Adding properly the license

* Fixing govet shadow error

* Fixing some tests

* Fixing TestSearchPostsFromUser

* Fixing another test

* Fixing more tests

* Fixing more tests

* Removing SearchEngine redundant text from searchengine module code

* Fixing some reindexing problems in members updates

* Fixing tests

* Addressing PR comments

* Reverting go.mod and go.sum

* Addressing PR comments

* Fixing tests compilation

* Fixing govet

* Adding search engine stop method

* Being more explicit on where we use includeDeleted

* Adding GetSqlSupplier test helper method

* Mocking elasticsearch start function

* Fixing tests

Co-authored-by: Miguel de la Cruz <miguel@mcrx.me>
Co-authored-by: mattermod <mattermod@users.noreply.github.com>

app/enterprise.go

@@ -9,6 +9,7 @@ import (
 	tjobs "github.com/mattermost/mattermost-server/v5/jobs/interfaces"
 	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
+	"github.com/mattermost/mattermost-server/v5/services/searchengine"
 )
 
 var accountMigrationInterface func(*Server) einterfaces.AccountMigrationInterface
@@ -35,9 +36,9 @@ func RegisterDataRetentionInterface(f func(*App) einterfaces.DataRetentionInterf
 	dataRetentionInterface = f
 }
 
-var elasticsearchInterface func(*App) einterfaces.ElasticsearchInterface
+var elasticsearchInterface func(*App) searchengine.SearchEngineInterface
 
-func RegisterElasticsearchInterface(f func(*App) einterfaces.ElasticsearchInterface) {
+func RegisterElasticsearchInterface(f func(*App) searchengine.SearchEngineInterface) {
 	elasticsearchInterface = f
 }
 
@@ -129,9 +130,6 @@ func (s *Server) initEnterprise() {
 	if complianceInterface != nil {
 		s.Compliance = complianceInterface(s.FakeApp())
 	}
-	if elasticsearchInterface != nil {
-		s.Elasticsearch = elasticsearchInterface(s.FakeApp())
-	}
 	if ldapInterface != nil {
 		s.Ldap = ldapInterface(s.FakeApp())
 	}
@@ -161,4 +159,8 @@ func (s *Server) initEnterprise() {
 	if clusterInterface != nil {
 		s.Cluster = clusterInterface(s)
 	}
+
+	if elasticsearchInterface != nil {
+		s.SearchEngine.RegisterElasticsearchEngine(elasticsearchInterface(s.FakeApp()))
+	}
 }