aws_subnet

Provides an VPC subnet resource.

Example Usage

Basic Usage

resource "aws_subnet" "main" {
  vpc_id     = "${aws_vpc.main.id}"
  cidr_block = "10.0.1.0/24"

  tags {
    Name = "Main"
  }
}

Subnets In Secondary VPC CIDR Blocks

When managing subnets in one of a VPC's secondary CIDR blocks created using a aws_vpc_ipv4_cidr_block_association resource, it is recommended to reference that resource's vpc_id attribute to ensure correct dependency ordering.

resource "aws_vpc_ipv4_cidr_block_association" "secondary_cidr" {
  vpc_id     = "${aws_vpc.main.id}"
  cidr_block = "172.2.0.0/16"
}

resource "aws_subnet" "in_secondary_cidr" {
  vpc_id     = "${aws_vpc_ipv4_cidr_block_association.secondary_cidr.vpc_id}"
  cidr_block = "172.2.0.0/24"
}

Argument Reference

The following arguments are supported:

• availability_zone- (Optional) The AZ for the subnet.
• cidr_block - (Required) The CIDR block for the subnet.
• ipv6_cidr_block - (Optional) The IPv6 network range for the subnet, in CIDR notation. The subnet size must use a /64 prefix length.
• map_public_ip_on_launch - (Optional) Specify true to indicate that instances launched into the subnet should be assigned a public IP address. Default is false.
• assign_ipv6_address_on_creation - (Optional) Specify true to indicate that network interfaces created in the specified subnet should be assigned an IPv6 address. Default is false
• vpc_id - (Required) The VPC ID.
• tags - (Optional) A mapping of tags to assign to the resource.

Attributes Reference

In addition to all arguments above, the following attributes are exported:

• id - The ID of the subnet
• availability_zone- The AZ for the subnet.
• cidr_block - The CIDR block for the subnet.
• vpc_id - The VPC ID.
• ipv6_cidr_block_association_id - The association ID for the IPv6 CIDR block.
• ipv6_cidr_block - The IPv6 CIDR block.

Import

Subnets can be imported using the subnet id, e.g.

$ terraform import aws_subnet.public_subnet subnet-9d4a7b6c