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/helper_test.go

@@ -19,6 +19,7 @@ import (
 	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/store"
 	"github.com/mattermost/mattermost-server/v5/store/localcachelayer"
+	"github.com/mattermost/mattermost-server/v5/store/sqlstore"
 	"github.com/mattermost/mattermost-server/v5/store/storetest/mocks"
 	"github.com/mattermost/mattermost-server/v5/testlib"
 	"github.com/mattermost/mattermost-server/v5/utils"
@@ -94,6 +95,11 @@ func setupTestHelper(dbStore store.Store, enterprise bool, includeCacheLayer boo
 	}
 
 	th.App.UpdateConfig(func(cfg *model.Config) { *cfg.ServiceSettings.ListenAddress = prevListenAddress })
+
+	th.App.Srv().SearchEngine = mainHelper.SearchEngine
+
+	th.App.Srv().Store.MarkSystemRanUnitTests()
+
 	th.App.UpdateConfig(func(cfg *model.Config) { *cfg.TeamSettings.EnableOpenServer = true })
 
 	// Disable strict password requirements for test
@@ -569,6 +575,10 @@ func (me *TestHelper) TearDown() {
 	}
 }
 
+func (me *TestHelper) GetSqlSupplier() *sqlstore.SqlSupplier {
+	return mainHelper.GetSQLSupplier()
+}
+
 func (me *TestHelper) ResetRoleMigration() {
 	sqlSupplier := mainHelper.GetSQLSupplier()
 	if _, err := sqlSupplier.GetMaster().Exec("DELETE from Roles"); err != nil {