terraform-plugin-docs

page_title: “random_id Resource - terraform-provider-random” subcategory: "" description: |- The resource random_id generates random numbers that are intended to be used as unique identifiers for other resources. If the output is considered sensitive, and should not be displayed in the CLI, use random_bytes instead. This resource does use a cryptographic random number generator in order to minimize the chance of collisions, making the results of this resource when a 16-byte identifier is requested of equivalent uniqueness to a type-4 UUID. This resource can be used in conjunction with resources that have the create_before_destroy lifecycle flag set to avoid conflicts with unique names during the brief period where both the old and new resources exist concurrently.

random_id (Resource)

The resource random_id generates random numbers that are intended to be used as unique identifiers for other resources. If the output is considered sensitive, and should not be displayed in the CLI, use random_bytes instead.

This resource does use a cryptographic random number generator in order to minimize the chance of collisions, making the results of this resource when a 16-byte identifier is requested of equivalent uniqueness to a type-4 UUID.

This resource can be used in conjunction with resources that have the create_before_destroy lifecycle flag set to avoid conflicts with unique names during the brief period where both the old and new resources exist concurrently.

Example Usage

# The following example shows how to generate a unique name for an AWS EC2
# instance that changes each time a new AMI id is selected.

resource "random_id" "server" {
  keepers = {
    # Generate a new id each time we switch to a new AMI id
    ami_id = var.ami_id
  }

  byte_length = 8
}

resource "aws_instance" "server" {
  tags = {
    Name = "web-server ${random_id.server.hex}"
  }

  # Read the AMI id "through" the random_id resource to ensure that
  # both will change together.
  ami = random_id.server.keepers.ami_id

  # ... (other aws_instance arguments) ...
}

Schema

Required

byte_length (Number) The number of random bytes to produce. The minimum value is 1, which produces eight bits of randomness.

Optional

keepers (Map of String) Arbitrary map of values that, when changed, will trigger recreation of resource. See the main provider documentation for more information.
prefix (String) Arbitrary string to prefix the output value with. This string is supplied as-is, meaning it is not guaranteed to be URL-safe or base64 encoded.

Read-Only

b64_std (String) The generated id presented in base64 without additional transformations.
b64_url (String) The generated id presented in base64, using the URL-friendly character set: case-sensitive letters, digits and the characters _ and -.
dec (String) The generated id presented in non-padded decimal digits.
hex (String) The generated id presented in padded hexadecimal digits. This result will always be twice as long as the requested byte length.
id (String) The generated id presented in base64 without additional transformations or prefix.

Import

Import is supported using the following syntax:

# Random IDs can be imported using the b64_url with an optional prefix. This
# can be used to replace a config value with a value interpolated from the
# random provider without experiencing diffs.

# Example with no prefix:
terraform import random_id.server p-9hUg

# Example with prefix (prefix is separated by a ,):
$ terraform import random_id.server my-prefix-,p-9hUg