Given an AWS AMI ID and a region where that AMI is found, create a RegionMap for use with Amazon CloudFormation. Dependencies pip install boto3 pip install docopt

ami_lookup.py

"""AMI Lookup.

Given an AWS AMI ID and a region where that AMI is found, create a RegionMap
for use with Amazon CloudFormation.

Note it assumes your AWS credentials are set up according to the boto3 guide.
http://boto3.readthedocs.io/en/latest/guide/configuration.html.

TODO more error handling etc

Usage:
  ami_lookup.py <ami_id> <region>

Options:
  -h --help     Show this screen.  
"""
from docopt import docopt
import boto3
import boto.ec2

def get_ami_name(region_name, ami_id_in_region):    
    ec2 = boto3.resource('ec2', region_name=region_name)
    filters = [{'Name': 'image-id', 'Values': [ami_id_in_region]}]
    images = ec2.images.filter(Filters=filters).all()
    image_name = None
    for image in images:
        image_name = image.name
    return image_name

def amis_for_region(region_name, ami_id_in_region):
    region_list = ['us-east-2', 'us-east-1', 'us-west-1', 'us-west-2', 'ap-south-1', 'ap-northeast-2', \
        'ap-southeast-1', 'ap-southeast-2', 'ap-northeast-1', 'ca-central-1',  'eu-central-1', 'eu-west-1', \
        'eu-west-2', 'eu-west-3', 'sa-east-1']
    mappings = {}
    image_name = get_ami_name(region_name, ami_id_in_region)
    if image_name is not None:
        for region in region_list:          
            ec2 = boto3.resource('ec2', region_name=region)
            filters = [{'Name': 'name', 'Values': [image_name]}]
            images = ec2.images.filter(Filters=filters).all()
            if images is not None:
                for image in images:
                    mappings[region] = image.id
    return mappings

 
# Example: 
# python ami_lookup.py ami-2a0f324f us-east-2 
if __name__ == '__main__':
    arguments = docopt(__doc__)    

    print("-----------------------------------------------\n" + \
      "Generating map.  This will take up to a minute or more.\n" + \
      "Please wait...\n" + \
      "-----------------------------------------------\n")

    mappings = amis_for_region(arguments['<region>'], arguments['<ami_id>'])
    if len(mappings) > 0:
        # Bug trailing "," for last element in map
        print('"RegionMap" : {')
        for key, value in mappings.items():
            print("\t\"{0}\"   : {{ \"AMI\" : \"{1}\"}},".format(key, value))
        print('}')