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a python script to display ec2 name and ip address as ssh-config or hosts file.
#! /usr/bin/env python
import argparse
import os
import sys
import boto.ec2
def parse_args():
parser = argparse.ArgumentParser(
description='Display EC2 hosts in ssh-config or hosts file format',
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('-k', '--aws-key', type=str,
default=os.environ.get("AWS_ACCESS_KEY_ID"),
help='Amazon EC2 Key, defaults to ENV[AWS_ACCESS_KEY_ID]')
parser.add_argument('-s', '--aws-secret', type=str,
default=os.environ.get("AWS_SECRET_ACCESS_KEY"),
help='Amazon EC2 Secret, defaults to ENV[AWS_SECRET_ACCESS_KEY]')
parser.add_argument('-r', '--region', type=str,
default=os.environ.get("AWS_EC2_REGION"),
help='Amazon EC2 Region, defaults to us-east-1 or ENV[AWS_EC2_REGION]')
parser.add_argument('-t', '--tag', type=str,
default='Name', dest='name_tag',
help="Amazon EC2 Tag for instance name, defaults to 'Name'")
parser.add_argument('--prefix', type=str, default='',
help='prefix to the instance name')
parser.add_argument('--suffix', type=str, default='',
help='suffix to the instance name')
parser.add_argument('--domain', type=str, default='',
help='domain to the instance name')
parser.add_argument('--format', choices=['ssh', 'hosts'], default='ssh',
help='output format. ssh-config or hosts file style. ')
parser.add_argument('--filter', type=str, action='append', default=[],
help=('Amazon EC2 API filter to limit the result returned. '
'(Example: --filter instance-state-name=running)'))
parser.add_argument('--use-elastic-ip', action='store_true',
help='use elastic IP instead of private IP')
return parser.parse_args()
def main(opts):
aws_key = opts['aws_key']
aws_secret = opts['aws_secret']
region = opts['region']
name_tag = opts['name_tag']
prefix = opts['prefix']
suffix = opts['suffix']
domain = opts['domain']
format = opts['format']
filter = opts['filter']
use_elastic_ip = opts['use_elastic_ip']
filters = dict([f.split('=', 1) for f in filter])
if domain and not domain.startswith('.'):
domain = '.' + domain
ip_addr_attr = 'ip_address' if use_elastic_ip else 'private_ip_address'
# validation
if not aws_key or not aws_secret:
if not aws_key:
print >> sys.stderr,\
"AWS_ACCESS_KEY_ID not set in environment and not",\
"specified by -k AWS_KEY or --aws-key AWS_KEY"
if not aws_secret:
print >> sys.stderr,\
"AWS_SECRET_ACCESS_KEY not set in envoronment and not",\
"specified by -s AWS_SECRET or --aws-secret AWS_SECRET"
sys.exit(2)
region = region and boto.ec2.get_region(region,
aws_access_key_id=aws_key,
aws_secret_access_key=aws_secret)
conn = boto.ec2.connection.EC2Connection(aws_key, aws_secret,
region=region)
# list of (instance_name, ip_address)
instances = get_ec2_instances(conn, name_tag, ip_addr_attr, filters)
# sort by name
instances = sorted(instances)
# print out
print_fn = print_ssh_config if format == 'ssh' else print_hosts
print_fn(instances, prefix, suffix, domain)
def get_ec2_instances(conn, name_tag, ip_addr_attr, filters):
instances = [] # (instance_name, ip_address)
reservations = conn.get_all_instances(filters=filters)
for reservation in reservations:
for instance in reservation.instances:
instance_name = instance.tags.get(name_tag)
ip_address = getattr(instance, ip_addr_attr)
if instance_name and ip_address:
pair = (instance_name, ip_address)
instances.append(pair)
return instances
def print_ssh_config(instances, prefix, suffix, domain):
""" Print out as ssh-config file format """
for instance_name, ip_address in instances:
instance_name = prefix + instance_name + suffix + domain
# double quote if name contains space
instance_name = '"{0}"'.format(
instance_name) if ' ' in instance_name else instance_name
print "Host %s" % instance_name
print "Hostname %s" % ip_address
print ""
def print_hosts(instances, prefix, suffix, domain):
""" Print out as hosts file format """
for instance_name, ip_address in instances:
if ' ' in instance_name:
continue # skip if name contains space.
instance_name = prefix + instance_name + suffix + domain
print "%s\t%s" % (ip_address, instance_name)
if __name__ == '__main__':
args = vars(parse_args())
main(args)
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ttddyy commented Dec 12, 2012

Usage sample:

# display entries as ssh-config file format
./ec2-printconfig -k <aws_key> -s <aws_secret> -r us-west-2

# display entries as hosts file format
./ec2-printconfig --format hosts

# add prefix "my-" to instance name. (ex: my-foo, my-bar, ...)
./ec2-printconfig --prefix my-

# add domain "mydomain.com" to instance name. (ex: foo.mydomain.com, bar.mydomain.com, ...)
./ec2-printconfig --domain mydomain.com

# use elastic IP instead of private IP
./ec2-printconfig --use-elastic-ip

# filter instances. (ex: only running and monitored instances. )
./ec2-printconfig --filter monitoring-state=enabled --filter instance-state-name=running

# specify tag for ec2 instance name. (ex: assume there is "alias" tag)
./ec2-printconfig -t alias
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ttddyy commented Dec 12, 2012

@teambob

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teambob commented Jun 22, 2017

Hi,

I have modified this script and used it myself. I was wondering what license are you happy to use? Would GPLv2 be ok?

My fork is publicly accessible, so please feel free to check it out.

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