From cac80d73f43a38109054496e8ddaa40a24297069 Mon Sep 17 00:00:00 2001
From: Tadaya Tsuyukubo <tadboy@t-pon.com>
Date: Thu, 6 Dec 2012 21:03:26 -0800
Subject: [PATCH] ec2-printconfig script

print out ec2 instances as ssh-config or hosts file format.
---
 bin/ec2-printconfig | 131 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 131 insertions(+)
 create mode 100755 bin/ec2-printconfig

diff --git a/bin/ec2-printconfig b/bin/ec2-printconfig
new file mode 100755
index 0000000..d26ad1d
--- /dev/null
+++ b/bin/ec2-printconfig
@@ -0,0 +1,131 @@
+#! /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)