github.com/Kevinklinger/open_terraform@v0.11.12-beta1/website/docs/state/workspaces.html.md

---
layout: "docs"
page_title: "State: Workspaces"
sidebar_current: "docs-state-workspaces"
description: |-
  Workspaces allow the use of multiple states with a single configuration directory.
---

# Workspaces

Each Terraform configuration has an associated [backend](/docs/backends/index.html)
that defines how operations are executed and where persistent data such as
[the Terraform state](https://www.terraform.io/docs/state/purpose.html) are
stored.

The persistent data stored in the backend belongs to a _workspace_. Initially
the backend has only one workspace, called "default", and thus there is only
one Terraform state associated with that configuration.

Certain backends support _multiple_ named workspaces, allowing multiple states
to be associated with a single configuration. The configuration still
has only one backend, but multiple distinct instances of that configuration
to be deployed without configuring a new backend or changing authentication
credentials.

Multiple workspaces are currently supported by the following backends:

 * [AzureRM](/docs/backends/types/azurerm.html)
 * [Consul](/docs/backends/types/consul.html)
 * [GCS](/docs/backends/types/gcs.html)
 * [Local](/docs/backends/types/local.html)
 * [Manta](/docs/backends/types/manta.html)
 * [S3](/docs/backends/types/s3.html)

In the 0.9 line of Terraform releases, this concept was known as "environment".
It was renamed in 0.10 based on feedback about confusion caused by the
overloading of the word "environment" both within Terraform itself and within
organizations that use Terraform.

## Using Workspaces

Terraform starts with a single workspace named "default". This
workspace is special both because it is the default and also because
it cannot ever be deleted. If you've never explicitly used workspaces, then
you've only ever worked on the "default" workspace.

Workspaces are managed with the `terraform workspace` set of commands. To
create a new workspace and switch to it, you can use `terraform workspace new`;
to switch workspaces you can use `terraform workspace select`; etc.

For example, creating a new workspace:

```text
$ terraform workspace new bar
Created and switched to workspace "bar"!

You're now on a new, empty workspace. Workspaces isolate their state,
so if you run "terraform plan" Terraform will not see any existing state
for this configuration.
```

As the command says, if you run `terraform plan`, Terraform will not see
any existing resources that existed on the default (or any other) workspace.
**These resources still physically exist,** but are managed in another
Terraform workspace.

## Current Workspace Interpolation

Within your Terraform configuration, you may include the name of the current
workspace using the `${terraform.workspace}` interpolation sequence. This can
be used anywhere interpolations are allowed.

Referencing the current workspace is useful for changing behavior based
on the workspace. For example, for non-default workspaces, it may be useful
to spin up smaller cluster sizes. For example:

```hcl
resource "aws_instance" "example" {
  count = "${terraform.workspace == "default" ? 5 : 1}"

  # ... other arguments
}
```

Another popular use case is using the workspace name as part of naming or
tagging behavior:

```hcl
resource "aws_instance" "example" {
  tags {
    Name = "web - ${terraform.workspace}"
  }

  # ... other arguments
}
```

## When to use Multiple Workspaces

Named workspaces allow conveniently switching between multiple instances of
a _single_ configuration within its _single_ backend. They are convenient in
a number of situations, but cannot solve all problems.

A common use for multiple workspaces is to create a parallel, distinct copy of
a set of infrastructure in order to test a set of changes before modifying the
main production infrastructure. For example, a developer working on a complex
set of infrastructure changes might create a new temporary workspace in order
to freely experiment with changes without affecting the default workspace.

Non-default workspaces are often related to feature branches in version control.
The default workspace might correspond to the "master" or "trunk" branch,
which describes the intended state of production infrastructure. When a
feature branch is created to develop a change, the developer of that feature
might create a corresponding workspace and deploy into it a temporary "copy"
of the main infrastructure so that changes can be tested without affecting
the production infrastructure. Once the change is merged and deployed to the
default workspace, the test infrastructure can be destroyed and the temporary
workspace deleted.

When Terraform is used to manage larger systems, teams should use multiple
separate Terraform configurations that correspond with suitable architectural
boundaries within the system so that different components can be managed
separately and, if appropriate, by distinct teams. Workspaces _alone_
are not a suitable tool for system decomposition, because each subsystem should
have its own separate configuration and backend, and will thus have its own
distinct set of workspaces.

In particular, organizations commonly want to create a strong separation
between multiple deployments of the same infrastructure serving different
development stages (e.g. staging vs. production) or different internal teams.
In this case, the backend used for each deployment often belongs to that
deployment, with different credentials and access controls. Named workspaces
are _not_ a suitable isolation mechanism for this scenario.

Instead, use one or more [re-usable modules](/docs/modules/index.html) to
represent the common elements, and then represent each instance as a separate
configuration that instantiates those common elements in the context of a
different backend. In that case, the root module of each configuration will
consist only of a backend configuration and a small number of `module` blocks
whose arguments describe any small differences between the deployments.

Where multiple configurations are representing distinct system components
rather than multiple deployments, data can be passed from one component to
another using paired resources types and data sources. For example:

* Where a shared [Consul](https://consul.io/) cluster is available, use
  [`consul_key_prefix`](/docs/providers/consul/r/key_prefix.html) to
  publish to the key/value store and [`consul_keys`](/docs/providers/consul/d/keys.html)
  to retrieve those values in other configurations.

* In systems that support user-defined labels or tags, use a tagging convention
  to make resources automatically discoverable. For example, use
  [the `aws_vpc` resource type](/docs/providers/aws/r/vpc.html)
  to assign suitable tags and then
  [the `aws_vpc` data source](/docs/providers/aws/d/vpc.html)
  to query by those tags in other configurations.

* For server addresses, use a provider-specific resource to create a DNS
  record with a predictable name and then either use that name directly or
  use [the `dns` provider](/docs/providers/dns/index.html) to retrieve
  the published addresses in other configurations.

* If a Terraform state for one configuration is stored in a remote backend
  that is accessible to other configurations then
  [`terraform_remote_state`](/docs/providers/terraform/d/remote_state.html)
  can be used to directly consume its root module outputs from those other
  configurations. This creates a tighter coupling between configurations,
  but avoids the need for the "producer" configuration to explicitly
  publish its results in a separate system.

## Workspace Internals

Workspaces are technically equivalent to renaming your state file. They
aren't any more complex than that. Terraform wraps this simple notion with
a set of protections and support for remote state.

For local state, Terraform stores the workspace states in a directory called
`terraform.tfstate.d`. This directory should be be treated similarly to
local-only `terraform.tfstate`; some teams commit these files to version
control, although using a remote backend instead is recommended when there are
multiple collaborators.

For [remote state](/docs/state/remote.html), the workspaces are stored
directly in the configured [backend](/docs/backends). For example, if you
use [Consul](/docs/backends/types/consul.html), the workspaces are stored
by appending the workspace name to the state path. To ensure that
workspace names are stored correctly and safely in all backends, the name
must be valid to use in a URL path segment without escaping.

The important thing about workspace internals is that workspaces are
meant to be a shared resource. They aren't a private, local-only notion
(unless you're using purely local state and not committing it).

The "current workspace" name is stored only locally in the ignored
`.terraform` directory. This allows multiple team members to work on
different workspaces concurrently.