» Command: plan
terraform plan command is used to create an execution plan. Terraform
performs a refresh, unless explicitly disabled, and then determines what
actions are necessary to achieve the desired state specified in the
This command is a convenient way to check whether the execution plan for a
set of changes matches your expectations without making any changes to
real resources or to the state. For example,
terraform plan might be run
before committing a change to version control, to create confidence that it
will behave as expected.
-out argument can be used to save the generated plan to a file
for later execution with
terraform apply, which can be useful when
running Terraform in automation.
terraform plan [options] [dir]
plan requires no flags and looks in the current directory
for the configuration and state file to refresh.
If the command is given an existing saved plan as an argument, the
command will output the contents of the saved plan. In this scenario,
plan command will not modify the given plan. This can be used to
inspect a planfile.
The command-line flags are all optional. The list of available flags are:
-compact-warnings- If Terraform produces any warnings that are not accompanied by errors, show them in a more compact form that includes only the summary messages.
-destroy- If set, generates a plan to destroy all the known resources.
-detailed-exitcode- Return a detailed exit code when the command exits. When provided, this argument changes the exit codes and their meanings to provide more granular information about what the resulting plan contains:
- 0 = Succeeded with empty diff (no changes)
- 1 = Error
- 2 = Succeeded with non-empty diff (changes present)
-input=true- Ask for input for variables if not directly set.
-lock=true- Lock the state file when locking is supported.
-lock-timeout=0s- Duration to retry a state lock.
-no-color- Disables output with coloring.
-out=path- The path to save the generated execution plan. This plan can then be used with
terraform applyto be certain that only the changes shown in this plan are applied. Read the warning on saved plans below.
-refresh=true- Update the state prior to checking for differences.
-var-file=foo- Set variables in the Terraform configuration from a variable file. If a
.auto.tfvarsfiles are present in the current directory, they will be automatically loaded.
terraform.tfvarsis loaded first and the
.auto.tfvarsfiles after in alphabetical order. Any files specified by
-var-fileoverride any values set automatically from files in the working directory. This flag can be used multiple times.
» Resource Targeting
-target option can be used to focus Terraform's attention on only a
subset of resources.
Resource Address syntax is used
to specify the constraint. The resource address is interpreted as follows:
If the given address has a resource spec, only the specified resource is targeted. If the named resource uses
countand no explicit index is specified in the address (i.e. aws_instance.example), all of the instances sharing the given resource name are targeted.
If the given address does not have a resource spec, and instead just specifies a module path, the target applies to all resources in the specified module and all of the descendent modules of the specified module.
This targeting capability is provided for exceptional circumstances, such
as recovering from mistakes or working around Terraform limitations. It
is not recommended to use
-target for routine operations, since this can
lead to undetected configuration drift and confusion about how the true state
of resources relates to configuration.
Instead of using
-target as a means to operate on isolated portions of very
large configurations, prefer instead to break large configurations into
several smaller configurations that can each be independently applied.
Data sources can be used to access
information about resources created in other configurations, allowing
a complex system architecture to be broken down into more manageable parts
that can be updated independently.
» Security Warning
Saved plan files (with the
-out flag) encode the configuration,
state, diff, and variables. Variables are often used to store secrets.
Therefore, the plan file can potentially store secrets.
Terraform itself does not encrypt the plan file. It is highly recommended to encrypt the plan file if you intend to transfer it or keep it at rest for an extended period of time.
Future versions of Terraform will make plan files more secure.