HCP Terraform - How to set "remote" backend partial configuration to manage different environments with Terraform Cloud

Problem

When using the same Terraform configuration to manage multiple environments (e.g., development, staging, production) in HCP Terraform, you need a way to dynamically specify which workspace to use for each environment during initialization.

Cause

The Terraform cloud block, which configures the HCP Terraform integration, does not support variable interpolation within its configuration block. This means you cannot use variables to define the organization or workspace name directly in the main configuration file.

Solution

To manage different environments, you can leverage the HCP Terraform integration's support for partial configuration. This approach allows you to provide the remaining backend configuration details dynamically at initialization.

Procedure

1. Define a partial cloud block.

   In your main Terraform configuration file (e.g., main.tf), define an empty cloud block. This tells Terraform that you intend to use HCP Terraform but will provide the details later.

   terraform {
     cloud {}
   }

2. Create environment-specific configuration files.

   For each of your environments, create a separate backend configuration file with an .hcl extension (e.g., dev.hcl, test.hcl, prod.hcl). Place these files in the root of your configuration directory.

   Each file should contain the organization and workspace name for that specific environment. Replace YOUR_ORG and YOUR_WORKSPACE_NAME with your actual values.

   Example content for dev.hcl:

   organization = "YOUR_ORG"
   
   workspaces {
     name = "YOUR_WORKSPACE_NAME"
   }

3. Initialize Terraform with the specific backend configuration.

   When running terraform init, use the -backend-config flag to specify which environment's configuration file to use. You can also set the TF_CLI_ARGS_init environment variable to apply this flag automatically.

   To initialize the development environment, run the following command:

   $ terraform init -backend-config=dev.hcl

   This method allows you to switch between different HCP Terraform workspaces while sharing the same Terraform codebase across all your environments.

   Additional Information

   For further clarification/assistance, please contact support at tf-cloud@hashicorp.support or submit a ticket via our support portal.