Easily get ec2 public hosts, open a shell or run commands...

ec2-host.py

#!/usr/bin/env python
import os
import sys
import getopt
import boto
from sys import stderr


_ec2 = None


def short_usage():
    print >>stderr, """Usage: ec2-host [-k KEY] [-s SECRET] [NAME]
    ec2-host django8 => ec2-53-19-113-121.compute-1.amazonaws.com
Try `ssh-distillery --help' for more information."""
    

def full_usage():
    print >>stderr, """Usage: ec2-host [-k KEY] [-s SECRET] [NAME]
Prints server host name.
      
      --help                 display this help and exit
  -k, --aws-key KEY          Amazon EC2 Key, defaults to ENV[AWS_KEY]
  -s, --aws-secret SECRET    Amazon EC2 Secret, defaults to ENV[AWS_SECRET]"""


def list_instances():
  instance_pairs = []
  for instance in ec2_instances():
      instance_name = instance.tags.get("Name")
      if instance.public_dns_name:
          pair = (instance_name, instance.public_dns_name)
          instance_pairs.append(pair)
  for pair in sorted(instance_pairs, key=lambda p: p[0]):
      print "%s\t%s" % pair


def print_host(name):
    filters = {'tag:Name': name}
    instances = ec2_instances(filters=filters)
    
    if len(instances) == 0:
        print >>stderr, 'Unable to match instance named "%s"' % name
        short_usage()
        sys.exit(1)
    
    print instances[0].public_dns_name


def ec2_instances(**kwargs):
  return [rsv.instances[0] for rsv in _ec2.get_all_instances(**kwargs)]


def main(argv):
    try:
        opts, args = getopt.getopt(argv, "hLk:s:",
                                         ["help", "aws-key", "aws-secret"])
    except getopt.GetoptError, err:
        print >>sys.stderr, err
        short_usage()
        sys.exit(2)
    
    aws_key = os.environ.get("AWS_KEY")
    aws_secret = os.environ.get("AWS_SECRET")
    
    for opt, arg in opts:
        if opt in ("-h", "--help"):
            full_usage()
            sys.exit()
        elif opt in("-k", "--aws-key"):
            aws_key = arg
        elif opt in("-s", "--aws-secret"):
            aws_secret = arg
    
    if not aws_key or not aws_secret:
        if not aws_key:
            print >>sys.stderr,\
            "AWS_KEY not set in environment and not",\
            "specified by --aws-key KEY or -k KEY"
        
        if not aws_secret:
            print >>sys.stderr,\
            "AWS_SECRET not set in environment and not",\
            "specified by --aws-secret SECRET or -s SECRET"
        
        short_usage()
        sys.exit(2)
    
    global _ec2
    _ec2 = boto.connect_ec2(aws_key, aws_secret)
    
    argc = len(args)
    if argc == 0:
        list_instances()
        sys.exit()
    else:
        if argc > 1:
            print >>stderr, "Warning: more than one name given"
        
        name = args[0]
        print_host(name)
        
if __name__ == "__main__":
    main(sys.argv[1:])

ec2-ssh.sh

#!/bin/sh
#/ Usage: ec2-ssh <instance-name>
#/ Open ssh connection to EC2 instance where tag:Name=<instance-name>
#/ For list of instance, run ec2-host without any paramteres

set -e

test $# -eq 0 -o $(expr "$*" : ".*--help") \
				-ne 0 -o $(expr "$*" : ".*-h") -ne 0 && {
    grep ^#/ < $0 |
    cut -c4-
    exit
}

# support user@instance-name format
IFS="@"; declare -a hostparts=($1) 

inst="${hostparts[1]}"
user="${hostparts[0]}"

if test -z "$inst"; then
	inst="$1"
	user="ubuntu"
fi

# get host from ec2-host command
host=$(ec2-host $inst)

# pass all other parameters (${@:2}) to ssh allowing
# things like: ec2-ssh nginx uptime
test -n "$host" && exec sh -c "ssh $user@$host ${@:2}"