ec2_instances_to_csv.py

#!/usr/bin/env python

# a quick script to export all instances from all regions to csv
import os
import boto3
from botocore.exceptions import ClientError
from datetime import datetime, timedelta
import logging
import sys
import csv


logging.getLogger('botocore').setLevel(logging.CRITICAL)
log = logging.getLogger()
log.handlers = []
handler = logging.StreamHandler(sys.stdout)
formatter = logging.Formatter(
    '%(asctime)4s %(name)4s [%(filename)s:%(lineno)s - %(funcName)s()] %(levelname)4s %(message)4s')
handler.setFormatter(formatter)
log.addHandler(handler)
log.setLevel(logging.INFO)


def get_tag_value(tags, key='Name'):
    """
    returns the value of the given tag
    """
    value = 'Null'
    if tags:
        for tag in tags:
            if key in tag['Key']:
                value = tag['Value']
    return value

def get_ami_name(instance_resource):
    """
    Get the AMI name from the instance resource
    """
    ami_name = ''
    try:
        ami_name = instance_resource.image.name
    except AttributeError:
        pass

    return ami_name


def __get_ec2_instance_resources(session_config):
    """
    Returns a collection of ec2 instances resource
    """
    session = boto3.session.Session(**session_config)
    try:
        instances = [i for i in session.resource('ec2').instances.all()]

    except ClientError as err:
        log.error(err)
        raise

    return instances

def get_regions():
    """
    return available regions
    """
    regions = []
    try:
        for region in boto3.client('ec2').describe_regions()['Regions']:
            regions.append(region['RegionName'])

    except:
        raise

    return regions

def get_aws_account():
    """
    Get the current account
    """
    sts_client = boto3.client('sts')
    account_id = sts_client.get_caller_identity()["Account"]
    return account_id

def get_ec2_instances(profile=None):
    """
    returns a list of ec2 instances
    """

    aws_profile = profile or os.environ.get('AWS_DEFAULT_PROFILE')

    ec2_headers = ['aws_profile', 'region', 'ami_id', 'ami_name', 'instance_id', 'instance_type', 'tag_Name', 'architecture', 'state', 'launch_time']
    ec2_instances = []
    ec2_instances.append({'headers': ec2_headers})
    for region in get_regions():
        log.info('Fetching instances in {}/{}'.format(profile, region))
        # setup our session parameters
        session_config = {'profile_name': profile, 'region_name': region }
        for i in __get_ec2_instance_resources(session_config):
            ec2_instances.append(
                {
                    'aws_profile': aws_profile,
                    'region': region,
                    'ami_id': i.image_id,
                    'ami_name': get_ami_name(i),
                    'instance_id': i.instance_id,
                    'instance_type': i.instance_type,
                    'tag_Name': get_tag_value(i.tags),
                    'architecture': i.architecture,
                    'state': i.state['Name'],
                    'launch_time': i.launch_time
                }
            )
        log.info('Found instances {}'.format(len(ec2_instances) -1))

    log.info('Total instances found in {} {}'.format(profile, len(ec2_instances) -1))
    return ec2_instances

def main():
    """
    """
    with open('config', 'r') as f:
        config = f.readlines()
        for i, profile in enumerate(config):
            instances = get_ec2_instances(profile.strip())
            if i == 0:
                to_csv(instances, True)
            else:
                to_csv(instances)


def to_csv(records, headers=False):
    """
    export a list of dict records to csv
    """
    fileout = './ec2_instances.csv'
    fields = records.pop(0)
    log.info('Writing records to csv')
    with open(fileout, 'a') as f:
        writer = csv.DictWriter(f, fieldnames=fields['headers'], lineterminator='\n')
        if headers:
            writer.writeheader()

        writer.writerows(records)

main()