README.md

Google CIDR Range Terraform module

This module queries Google's published CIDR ranges from TXT records attached to several _netblock*.google.com domains. This is the documented process for doing so specifically for outbound SMTP for SPF records, but contains the helpful note that those ranges are utilized for all GSuite services.

Basically we take those records, strip out the data we don't want, extract the IPv4 and IPv6 CIDR ranges and return them. Great for AWS Security Groups where you want to whitelist incoming GSuite traffic but don't want to maintain a whitelist by hand.

Usage

module "google_ip_ranges" {
  source = "github.com/ASAPPinc/terraform-google-ip-ranges?ref=v0.0.1"
}

resource "aws_security_group" "example" {
    name   = "allow-google-smtp"
    vpc_id = "vpc-12345"
    description = "Allow inbound SMTP traffic from Google services."

    ingress {
        protocol    = "tcp"
        from_port   = 25
        to_port     = 25
        cidr_blocks = ["${module.google_ip_ranges.all_cidrs}"]
    }
}

Inputs

Name	Description	Type	Default	Required
google_netblock_domains	The domains under which Google publishes their CIDR ranges as TXT records. You probably won't need to modify this.	list	_netblocks.google.com, _netblocks2.google.com, _netblocks3.google.com	no

Outputs

Name	Description
ipv4_cidrs	The IPv4 CIDR ranges returned from Google
ipv6_cidrs	The IPv6 CIDR ranges returned from Google
all_cidrs	IPv4 and IPv6 CIDR ranges combined

Authors

• Chad Horohoe

License

MIT licensed. See LICENSE for full details.