Merge pull request #1041 from mithunputhusseri/master

Modified the ReadMe and Error message for custom remote option. Closed issue #1040

ReadMe.md

@@ -119,7 +119,7 @@ general:
   restore_schema_on_cluster: ""
   upload_by_part: true           # UPLOAD_BY_PART
   download_by_part: true         # DOWNLOAD_BY_PART
-  use_resumable_state: true      # USE_RESUMABLE_STATE, allow resume upload and download according to the <backup_name>.resumable file
+  use_resumable_state: true      # USE_RESUMABLE_STATE, allow resume upload and download according to the <backup_name>.resumable file. Resumable state is not supported for custom method in remote storage.
 
   # RESTORE_DATABASE_MAPPING, restore rules from backup databases to target databases, which is useful when changing destination database, all atomic tables will be created with new UUIDs.
   # The format for this env variable is "src_db1:target_db1,src_db2:target_db2". For YAML please continue using map syntax
@@ -319,7 +319,7 @@ custom:
   download_command: ""         # CUSTOM_DOWNLOAD_COMMAND
   delete_command: ""           # CUSTOM_DELETE_COMMAND
   list_command: ""             # CUSTOM_LIST_COMMAND
-  command_timeout: "4h"          # CUSTOM_COMMAND_TIMEOUT
+  command_timeout: "4h"        # CUSTOM_COMMAND_TIMEOUT
 api:
   listen: "localhost:7171"     # API_LISTEN
   enable_metrics: true         # API_ENABLE_METRICS
@@ -869,4 +869,4 @@ OPTIONS:
    --full-interval value                      Interval for run 'create_remote'+'delete local' when stop create incremental backup sequence and create full backup, look format https://pkg.go.dev/time#ParseDuration
    --watch-backup-name-template value         Template for new backup name, could contain names from system.macros, {type} - full or incremental and {time:LAYOUT}, look to https://go.dev/src/time/format.go for layout examples
    
-```
+```

pkg/backup/upload.go

@@ -359,7 +359,7 @@ func (b *Backuper) validateUploadParams(ctx context.Context, backupName string,
 	}
 
 	if b.cfg.General.RemoteStorage == "custom" && b.resume {
-		return fmt.Errorf("can't resume for `remote_storage: custom`")
+		return fmt.Errorf("Resumable state not allowed for `remote_storage: custom`. Disable it by setting use_resumable_state=false in `general` config section")
 	}
 	if b.cfg.General.RemoteStorage == "s3" && len(b.cfg.S3.CustomStorageClassMap) > 0 {
 		for pattern, storageClass := range b.cfg.S3.CustomStorageClassMap {