» remote_state

Retrieves state data from a Terraform backend. This allows you to use the root-level outputs of one or more Terraform configurations as input data for another configuration.

Although this data source uses Terraform's backends, it doesn't have the same limitations as the main backend configuration. You can use any number of remote_state data sources with differently configured backends, and you can use interpolations when configuring them.

» Example Usage 

data "terraform_remote_state" "vpc" {
  backend = "atlas"
  config {
    name = "hashicorp/vpc-prod"
  }
}

# Terraform >= 0.12
resource "aws_instance" "foo" {
  # ...
  subnet_id = "${data.terraform_remote_state.vpc.outputs.subnet_id}"
}

# Terraform <= 0.11
resource "aws_instance" "foo" {
  # ...
  subnet_id = "${data.terraform_remote_state.vpc.subnet_id}"
}

» Argument Reference

The following arguments are supported:

  • backend - (Required) The remote backend to use.
  • workspace - (Optional) The Terraform workspace to use, if the backend supports workspaces.
  • config - (Optional; block) The configuration of the remote backend. The config block can use any arguments that would be valid in the equivalent terraform { backend "<TYPE>" { ... } } block. See the documentation of your chosen backend for details.
  • defaults - (Optional; block) Default values for outputs, in case the state file is empty or lacks a required output.

» Attributes Reference

In addition to the above, the following attributes are exported:

  • (v0.12+) outputs - An object containing every root-level output in the remote state.
  • (<= v0.11) <OUTPUT NAME> - Each root-level output in the remote state appears as a top level attribute on the data source.

» Root Outputs Only

Only the root-level outputs from the remote state are accessible. Outputs from modules within the state cannot be accessed. If you want a module output or a resource attribute to be accessible via a remote state, you must thread the output through to a root output.

For example:

module "app" {
  source = "..."
}

output "app_value" {
  value = "${module.app.value}"
}

In this example, the output value from the "app" module is available as app_value. If this root level output hadn't been created, then a remote state resource wouldn't be able to access the value output on the module.