ec2query.py

#!/usr/bin/env python3

# Simple Python script to lookup EC2 instance ip addresses based on the name tag.

import os
import argparse
import boto3
from appdirs import user_cache_dir
from tabulate import tabulate

appname = "ec2query"
appauthor = "Haydar Ciftci"

cache_dir = user_cache_dir(appname, appauthor)


def update():
    client = boto3.client('ec2')
    reservations = client.describe_instances()

    if not os.path.exists(cache_dir):
        os.mkdir(cache_dir)

    cache_file = cache_dir + os.path.sep + "ec2instances"

    with open(cache_file, 'w') as cache_file_open:
        for reservation in reservations['Reservations']:
            for instance in reservation['Instances']:
                if instance['State']['Name'] != 'running':
                    continue

                name = ""
                for tag in instance['Tags']:
                    if tag['Key'] == 'Name':
                        name = tag['Value']

                if instance['PrivateIpAddress']:
                    cache_file_open.write("{}\t{}\n".format(name.lower(), instance['PrivateIpAddress']))

    print("Written cache to " + cache_file)


def search(name, update_cache=True):
    if not os.path.exists(cache_dir):
        update()

    cache_file = cache_dir + os.path.sep + "ec2instances"
    results = []

    for line in open(cache_file, 'r'):
        if line.find(name) > -1:
            results.append(line.strip().split("\t"))

    if len(results) == 0 and update_cache:
        update()
        return search(name, False)

    print(tabulate(results, headers=["Name", "Address"]))


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Search for EC2 instances')
    parser.add_argument('name', type=str, nargs='?', help='Name of the EC2 instance')
    args = parser.parse_args()
    search(str(args.name).lower())

requirements.txt

boto3
appdirs
tabulate