» Resource Addressing
A Resource Address is a string that references a specific resource in a larger infrastructure. An address is made up of two parts:
[module path][resource spec]
Module path:
A module path addresses a module within the tree of modules. It takes the form:
module.A.module.B.module.C...
Multiple modules in a path indicate nesting. If a module path is specified without a resource spec, the address applies to every resource within the module. If the module path is omitted, this addresses the root module.
Resource spec:
A resource spec addresses a specific resource in the config. It takes the form:
resource_type.resource_name[N]
-
resource_type
- Type of the resource being addressed. -
resource_name
- User-defined name of the resource. -
[N]
- whereN
is a0
-based index into a resource with multiple instances specified by thecount
meta-parameter. Omitting an index when addressing a resource wherecount > 1
means that the address references all instances.
In Terraform v0.12 and later, a resource spec without a module path prefix matches only resources in the root module. In earlier versions, a resource spec without a module path prefix will match resources with the same type and name in any descendent module.
» Examples
Given a Terraform config that includes:
resource "aws_instance" "web" {
# ...
count = 4
}
An address like this:
aws_instance.web[3]
Refers to only the last instance in the config, and an address like this:
aws_instance.web
Refers to all four "web" instances.