Terraform for_each caution

Terraform Notes

For_Each Loop Caution

When using for_each, be sure to be mindful of what you want these new resources to be indexed as. Because if you ever try to change the index name, the resources must be destroyed and recreated. 

Example map variable

variable "account_map"{
    default = {
        "TEST-A-Key" = {
            "name" = "TEST-A-Name"
            "email" = "TEST-A@me.com"
        },
        "TEST-B-Key" = {
            "name" = "TEST-B-Name"
            "email" = "TEST-B@me.com"
        }
    }
}

When you create a resource based on the above map, you get this:

resourceType.name["TEST-A-Key"]
resourceType.name["TEST-B-Key"]

Unfortunately, in the above example (and in my real world case), I've tied the index name to be same as the name of the account. So when I went to updated the account name (the above variable is created from a file), it attempted to delete all my account resources. So now my only choice is to delete state of these resources and re-import OR live with mis-matched account name and index string of the resources.

So take caution and use some index string that describes the variable, not the specific content. Or maybe you don't mind destroy and create whenever you want to change a name.