I have 2 infrastructures (lets say beta and alpha) both created via Terraform. I created a peering connections from alpha to beta in alpha terraform. Peering is created and active, seems nothing wrong. I didn’t change anything on beta terraform regarding for alpha-beta vpc peering, all the implementations are made through alpha terraform. But when I try to work on beta terraform for other things, it tries to overwrite beta route tables and remove alpha vpc peering from the beta route tables. As I said, there is no configuration on beta terraform related with alpha vpc. When I write the vpc peering id and alpha vpc cidr as a route to the beta vpc route tables in beta terraform and then run terraform plan on beta, the problem is being solved. My question is, what causes this problem ?
If we try to setup peering connection between two terraform managed VPCs, is it mandatory to configure accepter VPC’s route tables accordingly to avoid any overwriting?
Thank you very much.