[MM-53428] Delete empty drafts on upsert (#24046)

* [MM-53428] Delete empty drafts on upsert

* Add migrations to fix existing drafts

* Fix CI

* Delete empty drafts entirely from the DB

* Fix lint

* Implement batch migration for deleting drafts

* Missing store layers

* Add updated mock

* Remove unnecessary test

* PR feedback

* Add check for cluster migration

* Fix MySQL

* Don't check for len<2

* Bit of PR feedback

* Use query builder for parameters

* PR feedback

* More PR feedback

* Merge'd

* unit test GetLastCreateAtAndUserIdValuesForEmptyDraftsMigration

* simplified builder interface

* fix DeleteEmptyDraftsByCreateAtAndUserId for MySQL

* rework as batch migration worker

* fix typo

* log ip address on version mismatches too

* simplify reset semantics

* remove trace log in favour of low spam

* document parameters for clarity

---------

Co-authored-by: Mattermost Build <build@mattermost.com>
Co-authored-by: Jesse Hallam <jesse.hallam@gmail.com>

server/public/model/draft.go

@@ -12,7 +12,7 @@ import (
 type Draft struct {
 	CreateAt  int64  `json:"create_at"`
 	UpdateAt  int64  `json:"update_at"`
-	DeleteAt  int64  `json:"delete_at"`
+	DeleteAt  int64  `json:"delete_at"` // Deprecated, we now just hard delete the rows
 	UserId    string `json:"user_id"`
 	ChannelId string `json:"channel_id"`
 	RootId    string `json:"root_id"`

server/public/model/job.go

@@ -36,6 +36,7 @@ const (
 	JobTypeHostedPurchaseScreening      = "hosted_purchase_screening"
 	JobTypeS3PathMigration              = "s3_path_migration"
 	JobTypeCleanupDesktopTokens         = "cleanup_desktop_tokens"
+	JobTypeDeleteEmptyDraftsMigration   = "delete_empty_drafts_migration"
 
 	JobStatusPending         = "pending"
 	JobStatusInProgress      = "in_progress"

server/public/model/migration.go

@@ -43,4 +43,5 @@ const (
 	MigrationKeyAddReadChannelContentPermissions       = "read_channel_content_permissions"
 	MigrationKeyElasticsearchFixChannelIndex           = "elasticsearch_fix_channel_index_migration"
 	MigrationKeyS3Path                                 = "s3_path_migration"
+	MigrationKeyDeleteEmptyDrafts                      = "delete_empty_drafts_migration"
 )