hugo_ec2_tools.py

import boto


def find_autoscaling_groups_by_instance(instance_id):
    asg = boto.connect_autoscale()
     
    groups = []
    g = asg.get_all_groups()
    groups.extend(g)
    while g.next_token:
        g = asg.get_all_groups(next_token=g.next_token)
        groups.extend(g)
        
    result = []
    for group in groups:
        instance_ids = [i.instance_id for i in group.instances]
        if instance_id in instance_ids:
            result.append(group.name)
    return result


def find_route_tables_by_instance_id(instance_id):
    vpc = boto.connect_vpc()
    route_tables = vpc.get_all_route_tables()

    result = []
    for route_table in route_tables:
        for route in route_table.routes:
            if route.instance_id == instance_id:
                result.append(route_table.id)
    return result


def find_subnets_associated_to_route_tables(route_table_ids):
    result = []
    vpc = boto.connect_vpc()
    route_tables = vpc.get_all_route_tables(route_table_ids)
    for route_table in route_tables:
        for association in route_table.associations:
            if association.subnet_id:
                result.append(association.subnet_id)
    return result


def find_instances_that_belong_to_a_subnet(subnet_id):
    ec2 = boto.connect_ec2()
    all_instances = ec2.get_only_instances()

    result = []
    for instance in all_instances:
        if instance.subnet_id == subnet_id:
            result.append(instance.instance_id)
    return result




INSTANCE_ID = 'i-XYZ'
asgs = find_autoscaling_groups_by_instance(INSTANCE_ID)
route_table_ids = find_route_tables_by_instance_id(INSTANCE_ID)
subnet_ids = find_subnets_associated_to_route_tables(route_table_ids)

print "instance: {}".format(INSTANCE_ID)
print "autoscaling groups: {}".format(repr(asgs))
print "route tables: {}".format(repr(route_table_ids))
print "subnets: {}".format(repr(subnet_ids))