Backend Type: remote

The remote backend is unique among all other OpenTofu backends because it can both store state snapshots and execute CLI-driven run workflow operations for TF Automation and Collaboration Software (TACOS) backends. It used to be called an "enhanced" backend.

If your TACOS provider enables full remote operations, you can execute commands such as tofu plan or tofu apply within the TACOS runtime environment, with log output streaming directly to your local terminal. Remote plans and applies use variable values from the associated remote workspace.

You can also use TACOS with local operations, where only state is stored in the TACOS remote backend.

Command Support​

The remote backend supports the following OpenTofu commands:

• apply
• console
• destroy
• fmt
• get
• graph
• import
• init
• output
• plan
• providers
• show
• state (supports all sub-commands: list, mv, pull, push, rm, show)
• taint
• untaint
• validate
• version
• workspace

Workspaces​

The remote backend can work with either a single remote workspace, or with multiple similarly-named remote workspaces (like networking-dev and networking-prod). The workspaces block of the backend configuration determines which mode it uses:

• To use a single remote workspace, set workspaces.name to the remote workspace's full name (like networking-prod).

• To use multiple remote workspaces, set workspaces.prefix to a prefix used in all of the desired remote workspace names. For example, set prefix = "networking-" to use remote workspaces with names like networking-dev and networking-prod. This is helpful when mapping multiple OpenTofu CLI workspaces used in a single OpenTofu configuration to multiple remote workspaces.

The backend configuration requires either name or prefix. Omitting both or setting both results in a configuration error.

If previous state is present when you run tofu init and the corresponding remote workspaces are empty or absent, OpenTofu will create workspaces and update the remote state accordingly. However, if your workspace requires variables or a specific version of OpenTofu for remote operations, we recommend that you create your remote workspaces on TACOS before running any remote operations against them.

Workspace Names​

OpenTofu uses shortened names without the common prefix to interact with workspaces on the command line. For example, if prefix = "networking-", use tofu workspace select prod to switch to the OpenTofu CLI workspace prod within the current configuration. However, remote OpenTofu operations such as plan and apply for that OpenTofu CLI workspace will take place in the remote workspace networking-prod.

Because of this, the terraform.workspace interpolation expression produces different results depending on whether a remote workspace is configured to perform operations locally or remotely. For example, in a remote workspace called networking-prod created with prefix = "networking-" the expression produces the following:

• For local operations, terraform.workspace = prod
• For remote operations, terraform.workspace= networking-prod

Example Configurations​

Basic Configuration​

# Using a single workspace:
terraform {
  backend "remote" {
    hostname = "app.example.io"
    organization = "company"

    workspaces {
      name = "my-app-prod"
    }
  }
}

# Using multiple workspaces:
terraform {
  backend "remote" {
    hostname = "app.example.io"
    organization = "company"

    workspaces {
      prefix = "my-app-"
    }
  }
}

Using CLI Input​

# main.tf
terraform {
  required_version = "~> 0.12.0"

  backend "remote" {}
}

Backend configuration file:

# config.remote.tfbackend
workspaces { name = "workspace" }
hostname     = "app.example.io"
organization = "company"

Running tofu init with the backend file:

tofu init -backend-config=config.remote.tfbackend

Data Source Configuration​

data "terraform_remote_state" "foo" {
  backend = "remote"

  config = {
    organization = "company"

    workspaces = {
      name = "workspace"
    }
  }
}

Configuration Variables​

The following configuration options are supported:

• hostname - (Required) The remote backend hostname to connect to.

• organization - (Required) The name of the organization containing the targeted workspace(s).

• token - (Optional) The token used to authenticate with the remote backend. We recommend omitting the token from the configuration, and instead using tofu login or manually configuring credentials in the CLI config file.

• workspaces - (Required) A block specifying which remote workspace(s) to use. The workspaces block supports the following keys:

  • name - (Optional) The full name of one remote workspace. When configured, only the default workspace can be used. This option conflicts with prefix.
  • prefix - (Optional) A prefix used in the names of one or more remote workspaces, all of which can be used with this configuration. The full workspace names are used in TACOS, and the short names (minus the prefix) are used on the command line for OpenTofu CLI workspaces. If omitted, only the default workspace can be used. This option conflicts with name.

Command Line Arguments​

For configurations that include a backend "remote" block, commands that make local modifications to OpenTofu state and then push them back up to the remote workspace accept the following option to modify that behavior:

• -ignore-remote-version - Override checking that the local and remote OpenTofu versions agree, making an operation proceed even when there is a mismatch.

  Normally state-modification operations require using a local version of OpenTofu CLI which is compatible with the OpenTofu version selected for the remote workspace as part of its settings. This is to avoid the local operation creating a new state snapshot which the workspace's remote execution environment would then be unable to decode.

  Overriding this check can result in a remote workspace that is no longer able to complete remote operations, so we recommend against using this option.

Excluding Files from Upload with .terraformignore​

When executing a remote plan or apply in a CLI-driven run, an archive of your configuration directory is uploaded to TACOS. You can define paths to ignore from upload via a .terraformignore file at the root of your configuration directory. If this file is not present, the archive will exclude the following by default:

• .git/ directories
• .terraform/ directories (exclusive of .terraform/modules)

The .terraformignore file can include rules as one would include in a .gitignore file

• Comments (starting with #) or blank lines are ignored
• End a pattern with a forward slash / to specify a directory
• Negate a pattern by starting it with an exclamation point !

Note that unlike .gitignore, only the .terraformignore at the root of the configuration directory is considered.