Merge pull request #31849 from hashicorp/workspaces-confusion-fixes

Update workspace documentation
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@ -7,72 +7,80 @@ description: >-
# Managing Workspaces
In Terraform CLI, _workspaces_ are separate instances of
[state data](/language/state) that can be used from the same working
directory. You can use workspaces to manage multiple non-overlapping groups of
resources with the same configuration.
Workspaces in the Terraform CLI refer to separate instances of [state data](/language/state) inside the same Terraform working directory. They are distinctly different from [workspaces in Terraform Cloud](/cloud-docs/workspaces), which each have their own Terraform configuration and function as separate working directories.
- Every [initialized working directory](/cli/init) has at least
one workspace. (If you haven't created other workspaces, it is a workspace
named `default`.)
- For a given working directory, only one workspace can be _selected_ at a time.
- Most Terraform commands (including [provisioning](/cli/run)
and [state manipulation](/cli/state) commands) only interact
with the currently selected workspace.
- Use [the `terraform workspace select` command](/cli/commands/workspace/select)
to change the currently selected workspace.
- Use the [`terraform workspace list`](/cli/commands/workspace/list),
[`terraform workspace new`](/cli/commands/workspace/new), and
[`terraform workspace delete`](/cli/commands/workspace/delete) commands
to manage the available workspaces in the current working directory.
Terraform relies on state to associate resources with real-world objects. When you run the same configuration multiple times with separate state data, Terraform can manage multiple sets of non-overlapping resources.
-> **Note:** Terraform Cloud and Terraform CLI both have features called
"workspaces," but they're slightly different. Terraform Cloud's workspaces
behave more like completely separate working directories.
Workspaces can be helpful for specific [use cases](#use-cases), but they are not required to use the Terraform CLI. We recommend using [alternative approaches](#alternatives-to-workspaces) for complex deployments requiring separate credentials and access controls.
## The Purpose of Workspaces
Since most of the resources you can manage with Terraform don't include a unique
name as part of their configuration, it's common to use the same Terraform
configuration to provision multiple groups of similar resources.
## Managing CLI Workspaces
Terraform relies on [state](/language/state) to associate resources with
real-world objects, so if you run the same configuration multiple times with
completely separate state data, Terraform can manage many non-overlapping groups
of resources. In some cases you'll want to change
[variable values](/language/values/variables) for these different
resource collections (like when specifying differences between staging and
production deployments), and in other cases you might just want many instances
of a particular infrastructure pattern.
Every [initialized working directory](/cli/init) starts with one workspace named `default`.
The simplest way to maintain multiple instances of a configuration with
completely separate state data is to use multiple
[working directories](/cli/init) (with different
[backend](/language/settings/backends/configuration) configurations per directory, if you
aren't using the default `local` backend).
Use the [`terraform workspace list`](/cli/commands/workspace/list), [`terraform workspace new`](/cli/commands/workspace/new), and [`terraform workspace delete`](/cli/commands/workspace/delete) commands to manage the available workspaces in the current working directory.
However, this isn't always the most _convenient_ way to handle separate states.
Terraform installs a separate cache of plugins and modules for each working
directory, so maintaining multiple directories can waste bandwidth and disk
space. You must also update your configuration code from version control
separately for each directory, reinitialize each directory separately when
changing the configuration, etc.
Use [the `terraform workspace select` command](/cli/commands/workspace/select) to change the currently selected workspace. For a given working directory, you can only select one workspace can be at a time. Most Terraform commands only interact with the currently selected workspace. This includes [provisioning](/cli/run) and [state manipulation](/cli/state).
When you provision infrastructure in each workspace, you usually need to manually specify different [input variables](/language/values/variables) to differentiate each collection. For example, you might deploy test infrastructure to a different region.
## Use Cases
You can create multiple [working directories](/cli/init) to maintain multiple instances of a configuration with completely separate state data. However, Terraform installs a separate cache of plugins and modules for each working directory, so maintaining multiple directories can waste bandwidth and disk space. This approach also requires extra tasks like updating configuration from version control for each directory separately and reinitializing each directory when you change the configuration. Workspaces are convenient because they let you create different sets of infrastructure with the same working copy of your configuration and the same plugin and module caches.
A common use for multiple workspaces is to create a parallel, distinct copy of
a set of infrastructure to test a set of changes before modifying production infrastructure.
Non-default workspaces are often related to feature branches in version control.
The default workspace might correspond to the `main` or `trunk` branch, which describes the intended state of production infrastructure. When a developer creates a feature branch for a change, they might also create a corresponding workspace and deploy into it a temporary copy of the main infrastructure. They can then test changes on the copy without affecting the production infrastructure. Once the change is merged and deployed to the default workspace, they destroy the test infrastructure and delete the temporary workspace.
### When Not to Use Multiple Workspaces
Workspaces let you quickly switch between multiple instances of a **single configuration** within its **single backend**. They are not designed to solve all problems.
When using Terraform to manage larger systems, you should create separate Terraform configurations that correspond to architectural boundaries within the system. This lets teams manage different components separately. Workspaces alone are not a suitable tool for system decomposition because each subsystem should have its own separate configuration and backend.
In particular, organizations commonly want to create a strong separation
between multiple deployments of the same infrastructure serving different
development stages or different internal teams. In this case, the backend for each deployment often has different credentials and access controls. CLI workspaces within a working directory use the same backend, so they are not a suitable isolation mechanism for this scenario.
## Alternatives to Workspaces
Instead of creating CLI workspaces, you can use one or more [re-usable modules](/language/modules/develop) 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](/language/settings/backends/configuration). The root module of each configuration consists only of a backend configuration and a small number of `module` blocks with arguments describing any small differences between the deployments.
When multiple configurations represent distinct system components rather than multiple deployments, you can pass data from one component to another using paired resources types and data sources.
- When a shared [Consul](https://www.consul.io/) cluster is available, use [`consul_key_prefix`](https://registry.terraform.io/providers/hashicorp/consul/latest/docs/resources/key_prefix) to publish to the key/value store and [`consul_keys`](https://registry.terraform.io/providers/hashicorp/consul/latest/docs/data-sources/keys) 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](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/vpc) to assign suitable tags and then [the `aws_vpc` data source](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/vpc) 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. Then you can either use that name directly or use [the `dns` provider](https://registry.terraform.io/providers/hashicorp/dns/latest/docs) to retrieve the published addresses in other configurations.
- If you store a Terraform state for one configuration in a remote backend that other configurations can access, then the other configurations can use [`terraform_remote_state`](/language/state/remote-state-data) to directly consume its root module outputs. This setup creates a tighter coupling between configurations, and the root configuration does not need to publish its results in a separate system.
Workspaces allow you to use the same working copy of your configuration and the
same plugin and module caches, while still keeping separate states for each
collection of resources you manage.
## Interactions with Terraform Cloud Workspaces
Terraform Cloud organizes infrastructure using workspaces, but its workspaces
act more like completely separate working directories; each Terraform Cloud
act more like completely separate working directories. Each Terraform Cloud
workspace has its own Terraform configuration, set of variable values, state
data, run history, and settings.
These two kinds of workspaces are different, but related. When [using Terraform
CLI as a frontend for Terraform Cloud](/cli/cloud), you can associate the current working
directory with one or more remote workspaces. If you associate the
directory with multiple workspaces (using workspace tags), you can use the
`terraform workspace` commands to select which remote workspace to use.
When you [integrate Terraform CLI with Terraform Cloud](/cli/cloud), you can associate the current CLI working directory with one or more remote Terraform Cloud workspaces. Then, use the `terraform workspace` commands to select the remote workspace you want to use for each run.
Refer to [CLI-driven Runs](/cloud-docs/run/cli) in the Terraform Cloud documentation for more details about using Terraform CLI with Terraform Cloud.
Refer to [CLI-driven Runs](/cloud-docs/run/cli) in the Terraform Cloud documentation for more details.
## Workspace Internals
Workspaces are technically equivalent to renaming your state file. Terraform then includes a set of protections and support for remote state.
Workspaces are also meant to be a shared resource. They are not private, unless you use purely local state and do not commit your state to version control.
For local state, Terraform stores the workspace states in a directory called `terraform.tfstate.d`. This directory should be treated similarly to local-only `terraform.tfstate`. Some teams commit these files to version control, but we recommend using a remote backend instead when there are multiple collaborators.
For [remote state](/language/state/remote), the workspaces are stored directly in the configured [backend](/language/settings/backends). For example, if you use [Consul](/language/settings/backends/consul), 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.
Terraform stores the current workspace name locally in the ignored `.terraform` directory. This allows multiple team members to work on different workspaces concurrently. Workspace names are also attached to associated remote workspaces in Terraform Cloud. For more details about workspace names in Terraform Cloud, refer to the [CLI Integration (recommended)](/cli/cloud/settings#arguments) and [remote backend](/language/settings/backends/remote#workspaces) and documentation.

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# Workspaces
Each Terraform configuration has an associated [backend](/language/settings/backends)
that defines how operations are executed and where persistent data such as
[the Terraform state](/language/state/purpose) are
stored.
Each Terraform configuration has an associated [backend](/language/settings/backends) that defines how Terraform executes operations and where Terraform stores persistent data, like [state](/language/state/purpose).
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
The persistent data stored in the backend belongs to a workspace. The backend initially has only one workspace containing one Terraform state associated with that configuration. Some backends support multiple named workspaces, allowing multiple states to be associated with a single configuration. The configuration still has only one backend, but you can deploy multiple distinct instances of that configuration without configuring a new backend or changing authentication
credentials.
Multiple workspaces are currently supported by the following backends:
-> **Note**: The Terraform CLI workspaces are different from [workspaces in Terraform Cloud](/cloud-docs/workspaces). Refer to [Initializing and Migrating](/cli/cloud/migrating) for details about migrating a configuration with multiple workspaces to Terraform Cloud.
* [AzureRM](/language/settings/backends/azurerm)
* [Consul](/language/settings/backends/consul)
* [COS](/language/settings/backends/cos)
* [GCS](/language/settings/backends/gcs)
* [Kubernetes](/language/settings/backends/kubernetes)
* [Local](/language/settings/backends/local)
* [OSS](/language/settings/backends/oss)
* [Postgres](/language/settings/backends/pg)
* [Remote](/language/settings/backends/remote)
* [S3](/language/settings/backends/s3)
## Backends Supporting Multiple Workspaces
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.
You can use multiple workspaces with the following backends:
- [AzureRM](/language/settings/backends/azurerm)
- [Consul](/language/settings/backends/consul)
- [COS](/language/settings/backends/cos)
- [GCS](/language/settings/backends/gcs)
- [Kubernetes](/language/settings/backends/kubernetes)
- [Local](/language/settings/backends/local)
- [OSS](/language/settings/backends/oss)
- [Postgres](/language/settings/backends/pg)
- [Remote](/language/settings/backends/remote)
- [S3](/language/settings/backends/s3)
-> **Note**: The Terraform CLI workspace concept described in this document is
different from but related to the Terraform Cloud
[workspace](/cloud-docs/workspaces) concept.
If you use multiple Terraform CLI workspaces in a single Terraform configuration
and are migrating that configuration to Terraform Cloud, refer to [Initializing and Migrating](/cli/cloud/migrating).
## 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.
~> **Important:** Workspaces are not appropriate for system decomposition or deployments requiring separate credentials and access controls. Refer to [Use Cases](/cli/workspaces#use-cases) in the Terraform CLI documentation for details and recommended alternatives.
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.
Terraform starts with a single, default workspace named `default` that you cannot delete. If you have not created a new workspace, you are using the default workspace in your Terraform working directory.
For example, creating a new workspace:
When you run `terraform plan` in a new workspace, Terraform does not access existing resources in other workspaces. These resources still physically exist, but you must switch workspaces to manage them.
```text
$ terraform workspace new bar
Created and switched to workspace "bar"!
Refer to the [Terraform CLI workspaces](/cli/workspaces) documentation for full details about how to create and use workspaces.
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
@ -103,103 +71,3 @@ resource "aws_instance" "example" {
# ... 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 "main" 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](/language/modules/develop) 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://www.consul.io/) cluster is available, use
[`consul_key_prefix`](https://registry.terraform.io/providers/hashicorp/consul/latest/docs/resources/key_prefix) to
publish to the key/value store and [`consul_keys`](https://registry.terraform.io/providers/hashicorp/consul/latest/docs/data-sources/keys)
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](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/vpc)
to assign suitable tags and then
[the `aws_vpc` data source](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/vpc)
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](https://registry.terraform.io/providers/hashicorp/dns/latest/docs) 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`](/language/state/remote-state-data)
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 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](/language/state/remote), the workspaces are stored
directly in the configured [backend](/language/settings/backends). For example, if you
use [Consul](/language/settings/backends/consul), 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 locally in the ignored
`.terraform` directory. This allows multiple team members to work on
different workspaces concurrently. Workspace names are also attached to associated remote workspaces in Terraform Cloud. For more details about workspace names in Terraform Cloud, refer to the [remote backend](/language/settings/backends/remote#workspaces) and [CLI Integration (recommended)](/cli/cloud/settings#arguments) documentation.