remote-state

Terraform module that accepts a component and a stack name and returns remote state outputs for the component.

The module supports all backends supported by Terraform and OpenTofu, plus the Atmos-specific static backend.

Errors

note

If you experience an error from the terraform_remote_state data source, this is most likely not an error in this module, but rather an error in the remote_state configuration in the referenced stack. This module performs no validation on the remote state configuration, and only modifies the configuration for the remote backend (to set the workspace name) and, only when var.privileged is set to true, the s3 configuration (to remove settings for assuming a role). If var.privileged is left at the default value of false and you are not using the remote backend, then this module will not modify the backend configuration in any way.

"Local" Backend

important

If the local backend has a relative path, it will be resolved relative to the current working directory, which is usually a root module referencing the remote state. However, when the local backend is created, the current working directory is the directory where the target root module is defined. This can cause the lookup to fail if the source is not reachable from the client directory as ../source.

For example, if your directory structure looks like this:

project
├── components
│   ├── client
│   │   └── main.tf
│   └── complex
│       └── source
│           └── main.tf
└── local-state
    └── complex
        └── source
            └── terraform.tfstate

Terraform code in project/components/complex/source can create its local state file (terraform.tfstate) in the local-state/complex/source directory using path = "../../../local-state/complex/source/terraform.tfstate". However, Terraform code in project/components/client that references the same local state using the same backend configuration will fail because the current working directory is project/components/client and the relative path will not resolve correctly.

Usage

The following example accepts a stack config my-stack (which in turn imports other YAML config dependencies) and returns remote state outputs from the s3 backend for my-vpc and eks Terraform components.

NOTE: The backend type (s3) and backend configuration for the components are defined in the stack YAML config files.

  module "remote_state_my_vpc" {
    source = "cloudposse/stack-config/yaml//modules/remote-state"
    # Cloud Posse recommends pinning every module to a specific version
    # version     = "x.x.x"
  
    stack                   = "my-stack"
    component               = "my-vpc"
  }
  
  module "remote_state_eks" {
    source = "cloudposse/stack-config/yaml//modules/remote-state"
    # Cloud Posse recommends pinning every module to a specific version
    # version     = "x.x.x"
  
    stack                   = "my-stack"
    component               = "eks"
  }

See examples/remote-state for more details.