get_ips.py

#!/usr/local/bin/python2.7
import boto3

ec2client = boto3.client('ec2')
response = ec2client.describe_instances()
public_dns = []
private_ip = []
clients = []
servers = []
for reservation in response["Reservations"]:
    for instance in reservation["Instances"]:
        if instance[u'PublicDnsName'] != "":
            public_dns.append(instance[u'PublicDnsName'])
            private_ip.append(instance[u'PrivateIpAddress'])

num_instances = len(private_ip)
print(num_instances)
num_clients = num_instances / 2
#num_clients = 4

print(public_dns)
print(len(public_dns))
print("")
print("")
print("Clients")
print(public_dns[0:num_clients])
print("")
print("Servers")
print(public_dns[num_clients:])
print(private_ip[num_clients:])
print("")
print("")
print("Client Hosts")
server_ips = ""
for i in range(0, len(private_ip[num_clients:]), 2):
    server_ips = server_ips + private_ip[num_clients + i] + ":13289#" + private_ip[num_clients + i + 1] + ":13289^"
print(server_ips)
client_hosts = ""
for client in public_dns[0:num_clients]:
    client_hosts = client_hosts + client + ","
print(client_hosts)