A script to add your ip to an ec2 security group.

update_sec_group.py

#!/usr/bin/env python3
""" update_sec_group.py

    Usage:
        ./update_sec_group.py [-v] SEC_GROUP_ID

        ./update_sec_group.py -a ACCESS_KEY -s SECRET_KEY [-v] SEC_GROUP_ID

    The -v option provides more verbose output.

    Adds the public ip of this machine to the given security group.

    In order to use this for yourself:

    * boto needs your AWS credentials. You can provide them directly
      with the -a and -s command-line parameters, or boto can find
      them in the file ~/.aws/credentials
    * Be sure that the region name below is correct for you.
    * Be sure that the ports you need are opened up below.
"""


# ______________________________________________________________________
# Imports

import json
import sys
import urllib.request

import boto3
from botocore.exceptions import ClientError


# ______________________________________________________________________
# Main

if __name__ == '__main__':

    access_key, secret_key = None, None
    is_verbose = False
    args = sys.argv
    for i in range(len(args) - 1, 0, -1):
        if args[i] == '-v':
            is_verbose = True
            del args[i]
        if args[i] == '-a':
            access_key = args[i + 1]
            del args[i + 1], args[i]
        if args[i] == '-s':
            secret_key = args[i + 1]
            del args[i + 1], args[i]

    if len(args) < 2:
        print(__doc__)
        sys.exit(0)

    sg_name = args[1]

    # Find our public ip address.
    ip   = urllib.request.urlopen('https://v4.ident.me').read().decode('utf8')
    cidr = ip + '/32'

    # Obtain an ec2 interface.
    if access_key is None:
        ec2 = boto3.client('ec2', region_name='us-west-2')
    else:
        ec2 = boto3.client(
                'ec2',
                aws_access_key_id = access_key,
                aws_secret_access_key = secret_key,
                region_name = 'us-west-2'
        )

    # Add our ipv4 address to what is allowed.
    try:
        data = ec2.authorize_security_group_ingress(
            GroupId = sg_name,
            IpPermissions = [
                {'IpProtocol': 'tcp',
                 'FromPort':   8888,
                 'ToPort':     8900,
                 'IpRanges': [{'CidrIp': cidr}]},
                {'IpProtocol': 'tcp',
                 'FromPort':   22,
                 'ToPort':     22,
                 'IpRanges': [{'CidrIp': cidr}]}
            ])
        if is_verbose:
            print('Received successful response:')
            print(json.dumps(data, indent=4))
            print()
        print('Success!')

    except ClientError as e:
        print(e)

I created this script because I avoid allowing open ports on my ec2 instances, and this makes it easier for me to allow my laptop to ssh in, or to use Jupyter, whenever I'm working from a new ip address.