aws-and-gcp-compute-ip-ranges.py

#!/usr/bin/python
import netaddr
import json 
import DNS # dns-python in ubuntu http://sourceforge.net/projects/pydns/ 
import urllib

awstotal = 0
gcptotal = 0

AWSURL = 'https://ip-ranges.amazonaws.com/ip-ranges.json'
GCPROOTDNS = '_cloud-netblocks.googleusercontent.com'

# calculate aws ec2 ip range
response = urllib.urlopen(AWSURL)
awsdata = json.loads(response.read())

for entry in awsdata['prefixes']:
    if entry['service'] == 'EC2': 
        ip = netaddr.IPNetwork(entry['ip_prefix'])
        awstotal += ip.size

# calculate gcp gce ip range

# TXT record looks like:
# dig +short _cloud-netblocks.googleusercontent.com TXT
# "v=spf1 include:_cloud-netblocks1.googleusercontent.com include:_cloud-netblocks2.googleusercontent.com 
# include:_cloud-netblocks3.googleusercontent.com include:_cloud-netblocks4.googleusercontent.com 
# include:_cloud-netblocks5.googleusercontent.com ?all"

maindnsrecord = DNS.dnslookup(GCPROOTDNS, "TXT")[0][0]
includes = [x for x in maindnsrecord.split() if x.startswith("include:")]

for toprecord in includes:
	subrecords = (DNS.dnslookup(toprecord.split(":")[1], "TXT"))[0][0]
	subrecords = subrecords.split(" ")
	subrecords = [x for x in subrecords if x.startswith("ip")]
	for ipblocks in subrecords:
		if ipblocks.startswith("ip4"):	
			ip4range = netaddr.IPNetwork(ipblocks[4:])
			gcptotal += ip4range.size
		if ipblocks.startswith("ip6"):
			ip6range = netaddr.IPNetwork(ipblocks[4:])
			gcptotal += ip6range.size

print "AWS total: " + str(awstotal)
print "GCP total: " + str(gcptotal)