Generate ssh aliases for aws ec2 instances

ssh-alias-for-aws-ec2.py

#!/usr/bin/env python3

"""
Create ssh shortcut alias
"""

import boto3

ec2 = boto3.client('ec2')

SECRETS_DIR = '/Volumes/Booy/Secrets'


def extract_tags(tags):
    required_tags = ['Name', 'type', 'role']
    map = {
        'Name': None,
        'type': None,
        'role': None,
    }
    for tag in tags:
        key = tag['Key']
        value = tag['Value']
        if key in required_tags:
            map[key] = value
    return map


def extract_instance_data(instance):
    """Extract user full data for an instance"""
    tag_map = extract_tags(instance['Tags'])
    return {
        'id': instance['InstanceId'],
        'key': (instance['KeyName']
                if 'KeyName' in instance
                else None),
        'ip': (instance['PublicIpAddress']
               if 'PublicIpAddress' in instance
               else None),
        'name': tag_map['Name'],
        'type': tag_map['type'],
        'role': tag_map['role'],

    }


def fetch_instances(response):
    instances = []
    for res in response['Reservations']:
        instances.extend(res['Instances'])
    return instances


def filter_instances(instances):
    """Filter all instances, if they don't have ip or name"""
    filtered = []
    for instance in instances:
        if 'ip' not in instance or 'name' not in instance:
            continue
        if 'type' in instance and instance['type'] == 'none':
            continue
        if (instance['ip'] is not None and
           instance['name'] is not None and
           instance['type'] is not None):
            filtered.append(instance)
    return filtered


if __name__ == '__main__':
    response = ec2.describe_instances(MaxResults=50)
    extracted = [extract_instance_data(instance)
                 for instance in fetch_instances(response)]
    instances = filter_instances(extracted)
    for instance in instances:
        print('alias {}="ssh -i {}/{}.pem ubuntu@{}"'
              .format(instance['name'], SECRETS_DIR,
                      instance['key'], instance['ip']))