aws_availability_zone
provides details about a specific availability zone (AZ)
in the current region.
This can be used both to validate an availability zone given in a variable and to split the AZ name into its component parts of an AWS region and an AZ identifier letter. The latter may be useful e.g., for implementing a consistent subnet numbering scheme across several regions by mapping both the region and the subnet letter to network numbers.
This is different from the aws_availability_zones
(plural) data source,
which provides a list of the available zones.
The following example shows how this data source might be used to derive VPC and subnet CIDR prefixes systematically for an availability zone.
variable "region_number" {
# Arbitrary mapping of region name to number to use in
# a VPC's CIDR prefix.
default = {
us-east-1 = 1
us-west-1 = 2
us-west-2 = 3
eu-central-1 = 4
ap-northeast-1 = 5
}
}
variable "az_number" {
# Assign a number to each AZ letter used in our configuration
default = {
a = 1
b = 2
c = 3
d = 4
e = 5
f = 6
}
}
# Retrieve the AZ where we want to create network resources
# This must be in the region selected on the AWS provider.
data "aws_availability_zone" "example" {
name = "eu-central-1a"
}
# Create a VPC for the region associated with the AZ
resource "aws_vpc" "example" {
cidr_block = cidrsubnet("10.0.0.0/8", 4, var.region_number[data.aws_availability_zone.example.region])
}
# Create a subnet for the AZ within the regional VPC
resource "aws_subnet" "example" {
vpc_id = aws_vpc.example.id
cidr_block = cidrsubnet(aws_vpc.example.cidr_block, 4, var.az_number[data.aws_availability_zone.example.name_suffix])
}
The arguments of this data source act as filters for querying the available availability zones. The given filters must match exactly one availability zone whose data will be exported as attributes.
all_availability_zones
- (Optional) Set to true
to include all Availability Zones and Local Zones regardless of your opt in status.filter
- (Optional) Configuration block(s) for filtering. Detailed below.name
- (Optional) Full name of the availability zone to select.state
- (Optional) Specific availability zone state to require. May be any of "available"
, "information"
or "impaired"
.zone_id
- (Optional) Zone ID of the availability zone to select.The filter
configuration block supports the following arguments:
name
- (Required) Name of the filter field. Valid values can be found in the EC2 DescribeAvailabilityZones API Reference.values
- (Required) Set of values that are accepted for the given filter field. Results will be selected if any given value matches.This data source exports the following attributes in addition to the arguments above:
group_name
- For Availability Zones, this is the same value as the Region name. For Local Zones, the name of the associated group, for example us-west-2-lax-1
.name_suffix
- Part of the AZ name that appears after the region name, uniquely identifying the AZ within its region.
For Availability Zones this is usually a single letter, for example a
for the us-west-2a
zone.
For Local and Wavelength Zones this is a longer string, for example wl1-sfo-wlz-1
for the us-west-2-wl1-sfo-wlz-1
zone.network_border_group
- The name of the location from which the address is advertised.opt_in_status
- For Availability Zones, this always has the value of opt-in-not-required
. For Local Zones, this is the opt in status. The possible values are opted-in
and not-opted-in
.parent_zone_id
- ID of the zone that handles some of the Local Zone or Wavelength Zone control plane operations, such as API calls.parent_zone_name
- Name of the zone that handles some of the Local Zone or Wavelength Zone control plane operations, such as API calls.region
- Region where the selected availability zone resides. This is always the region selected on the provider, since this data source searches only within that region.zone_type
- Type of zone. Values are availability-zone
, local-zone
, and wavelength-zone
.read
- (Default 20m
)