Command: state mv
The main function of Terraform state is to track the bindings between resource instance addresses in your configuration and the remote objects they represent. Normally Terraform automatically updates the state in response to actions taken when applying a plan, such as removing a binding for an remote object that has now been deleted.
You can use terraform state mv in the less common situation where you wish
to retain an existing remote object but track it as a different resource
instance address in Terraform, such as if you have renamed a resource block
or you have moved it into a different module in your configuration.
Usage
Usage: terraform state mv [options] SOURCE DESTINATION
Terraform will look in the current state for a resource instance, resource, or module that matches the given address, and if successful it will move the remote objects currently associated with the source to be tracked instead by the destination.
Both the source and destination addresses must use resource address syntax, and they must both refer to the same kind of object: you can only move a resource instance to another resource instance, a whole module instance to another whole module instance, etc. Furthermore, if you are moving a resource or a resource instance then you can only move it to a new address with the same resource type.
The most common uses for terraform state mv are when you have renamed a
resource block in your configuration or you've moved a resource block into
a child module, in both cases with the intention of retaining the existing
object but tracking it under a new name. By default Terraform will understand
moving or renaming a resource configuration as a request to delete the old
object and create a new object at the new address, and so terraform state mv
allows you to override that interpretation by pre-emptively attaching the
existing object to the new address in Terraform.
Warning: If you are using Terraform in a collaborative environment, you
must ensure that when you are using terraform state mv for a code refactoring
purpose you communicate carefully with your coworkers to ensure that nobody
makes any other changes between your configuration change and your
terraform state mv command, because otherwise they might inadvertently create
a plan that will destroy the old object and create a new object at the new
address.
This command also accepts the following options:
-dry-run- Report all of the resource instances that match the given address without actually "forgetting" any of them.-lock=false- Don't hold a state lock during the operation. This is dangerous if others might concurrently run commands against the same workspace.-lock-timeout=DURATION- Unless locking is disabled with-lock=false, instructs Terraform to retry acquiring a lock for a period of time before returning an error. The duration syntax is a number followed by a time unit letter, such as "3s" for three seconds.
For configurations using the HCP Terraform CLI integration or the remote backend
only, terraform state mv
also accepts the option
-ignore-remote-version.
The legacy options -backup and -backup-out
operate on a local state file only. Configurations using
the remote backend
must specify a local state file with the -state
option in order to use the -backup and -backup-out
options.
For configurations using
the local state mv only,
terraform state mv also accepts the legacy options
-state, -state-out, -backup, and -backup-out.
Example: Rename a Resource
Renaming a resource means making a configuration change like the following:
To tell Terraform that it should treat the new "helper" resource as a rename of the old "worker" resource, you can pair the above configuration change with the following command:
Example: Move a Resource Into a Module
If you originally wrote a resource in your root module but now wish to refactor
it into a child module, you can move the resource block into the child
module configuration, removing the original in the root module, and then
run the following command to tell Terraform to treat it as a move:
In the above example the new resource has the same name but a different module address. You could also change the resource name at the same time, if the new module organization suggests a different naming scheme:
Example: Move a Module Into a Module
You can also refactor an entire module into a child module. In the
configuration, move the module block representing the module into a different
module and then pair that change with a command like the following:
Example: Move a Particular Instance of a Resource using count
A resource defined with the count meta-argument
has multiple instances that are each identified by an integer. You can
select a particular instance by including an explicit index in your given
address:
A resource that doesn't use count or for_each has only a single resource
instance whose address is the same as the resource itself, and so you can
move from an address not containing an index to an address containing an index,
or the opposite, as long as the address type you use matches whether and how
each resource is configured:
Brackets ([, ]) have a special meaning in some shells, so you may need to
quote or escape the address in order to pass it literally to Terraform.
The above examples show the typical quoting syntax for Unix-style shells.
Example: Move a Resource configured with for_each
A resource defined with the for_each meta-argument
has multiple instances that are each identified by an string. You can
select a particular instance by including an explicit key in your given
address.
However, the syntax for strings includes quotes and the quote symbol often has special meaning in command shells, so you'll need to use the appropriate quoting and/or escaping syntax for the shell you are using. For example:
Unix-style shells, such as on Linux or macOS:
Windows Command Prompt (cmd.exe):
PowerShell:
Aside from the use of strings instead of integers for instance keys, the
treatment of for_each resources is similar to count resources and so
the same combinations of addresses with and without index components is
valid as described in the previous section.