find_ami.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import urllib, json, re, os, subprocess, sys, getopt

REGION=0; RELEASE=1; ARCH=3; TYPE=4; URL=6
TABLE_URL = "https://cloud-images.ubuntu.com/locator/ec2/releasesTable"

def usage():
    print 'Usage: find_ami.py [options]'
    print ''
    print 'Options:'
    print '\t-h, --help\tThis message'
    print '\t-r, --region\tAWS region       (default: us-east-1)'
    print '\t-v, --release\tUbuntu release   (default: trusty)'
    print '\t-a, --arch\tArchitecture     (default: amd64)'
    print '\t-t, --type\tInstance type    (default: hvm:instance-store)'
    print '\t--terraform\tFormat output as a series of Terraform \'-var\' flags'

try:
    opts, args = getopt.getopt(sys.argv[1:], "hr:v:a:t:", ["help", "region=", "release=", "arch=", "type=", "terraform"])
except getopt.GetoptError as err:
    print str(err) # will print something like "option -a not recognized"
    usage()
    sys.exit(2)

region_arg = 'us-east-1'
release_arg = 'trusty'
arch_arg = 'amd64'
type_arg = 'hvm:instance-store'
tf_format = False

for o, a in opts:
    if o in ("-h", "--help"):
        usage()
        sys.exit()
    elif o in ("-r", "--region"):
        region_arg = a
    elif o in ("-v", "--release"):
        release_arg = a
    elif o in ("-a", "--arch"):
        arch_arg = a
    elif o in ("-t", "--type"):
        type_arg = a
    elif o in ("--terraform"):
        tf_format = True
    else:
        assert False, "unhandled option"

response = urllib.urlopen(TABLE_URL)
data = json.loads(re.sub(r'\n',r'',response.read()).replace('],]',']]'))

if tf_format:
    output = []
    matches = [[elem[REGION], elem[TYPE], elem[URL]] for elem in data['aaData'] if elem[RELEASE] == release_arg and elem[ARCH] == arch_arg and elem[TYPE].startswith('hvm')]
    if not matches:
        sys.exit(1)
    for result in matches:
        match = re.search(r'>(.+)<', result[2])
        if match and match.group(1):
            output.append("-var 'ami_%s.%s=%s'" % (result[1].replace('hvm:','').replace('-','_'), result[0], match.group(1)))
    print " ".join(output)
else:
    matches = [elem[URL] for elem in data['aaData'] if elem[REGION] == region_arg and elem[RELEASE] == release_arg and elem[ARCH] == arch_arg and elem[TYPE] == type_arg]
    if not matches:
        sys.exit(1)
    match = re.search(r'>(.+)<', matches[0])
    if match and match.group(1):
        print match.group(1)
    else:
        sys.exit(1)

tf.sh

#!/bin/sh
terraform $* $(find_ami.py --terraform)