Skip to content

Data Source: aws_subnet_ids#

Provides a list of subnet IDs for a VPC.

!> The aws_subnet_ids data source has been deprecated and will be removed in future versions. Use the aws_subnets data source instead.

Example usage#

Specific examples#

The following shows all CIDR blocks for every subnet ID in a VPC.

variable vpc_id {}

data "aws_subnets" "example" {
  filter {
    name   = "vpc-id"
    values = [var.vpc_id]
  }
}

data "aws_subnet" "example" {
  for_each = toset(data.aws_subnets.example.ids)
  id       = each.value
}

output "subnet_cidr_blocks" {
  value = [for s in data.aws_subnet.example : s.cidr_block]
}

The following example retrieves a set of all subnets in a VPC with a custom Tier tag set to Private. So the aws_instance resource can loop through the subnets, putting instances across availability zones.

variable vpc_id {}

data "aws_subnets" "private" {
  filter {
    name   = "vpc-id"
    values = [var.vpc_id]
  }

  tags = {
    Tier = "Private"
  }
}

resource "aws_instance" "app" {
  for_each      = toset(data.aws_subnets.example.ids)
  ami           = "cmi-12345678" # add image id, change instance type if needed
  instance_type = "m1.micro"
  subnet_id     = each.value
}

For matching against tag Name, use:

data "aws_subnet_ids" "selected" {
  filter {
    name   = "tag:Name"
    values = [""] # insert values here
  }
}

Argument reference#

The following arguments are required:

  • vpc_id - (Required, String) The VPC that has attached subnets to filter from.

The following arguments are optional:

  • filter - (Optional, Block) One or more name/value pairs to use as filters.
  • tags - (Optional, Map of strings) Key-value pairs. Must exactly match pairs on the required resources.

filter#

  • name - (Required, String) The name of the filter.
    • Constraints: Filter names are case-sensitive
  • values - (Required, List of strings) One or more filter values.
    • Constraints: Filter values are case-sensitive

Attribute reference#

In addition to all arguments above, the following attribute is exported:

  • id - (String) The ID of the VPC.
  • ids - (List of strings) The list of found subnet IDs.