Update outputs.tf

db_instance_name = concat(aws_db_instance.postgresql_instance.*.name, [""])[0]

cette ligne engendre l'erreur: ╷ │ Error: Unsupported attribute │ │ on .terraform/modules/my_rds/outputs.tf line 10, in locals: │ 10: db_instance_name = concat(aws_db_instance.postgresql_instance.*.name, [""])[0] │ │ This object does not have an attribute named "name". ╵

pour regler le problème, il faut utiliser l'attribute 'db_name', la ligne deviens donc:

db_instance_name = concat(aws_db_instance.postgresql_instance.*.db_name, [""])[0]