S3にRPMがアップロードされたらレポジトリを更新するLambdaスクリプト

yum_package_update.py

import json
import urllib
import boto3
import os
import re

# constants
image_id = 'ami-59bdb937' # Amazon Linux AMI 2015.09.2 x86_64 HVM GP2
subnet_id = 'subnet-example'
instance_profile_name = 'InstanceProfileName'

s3 = boto3.client('s3')
ec2 = boto3.client('ec2')

def lambda_handler(event, context):
    # Get the object from the event and show its content type
    bucket = event['Records'][0]['s3']['bucket']['name']
    key = urllib.unquote_plus(event['Records'][0]['s3']['object']['key']).decode('utf8')
    s3.delete_object(Bucket=bucket, Key=key)
    
    # key: centos-packages/7/x86_64/re-index
    # target_path: s3://yum-repo-bucket/centos/7/x86_64/
    # sync_path: s3://yum-repo-bucket/centos-packages/7/x86_64/
    target_key = re.sub(r'([a-zA-Z]+)-packages/([^/]+)/([^/]+)/re-index', r'\1/\2/\3', key)
    target_path = "s3://%s/%s/" % (bucket, target_key)
    sync_path = "s3://%s/%s/" % (bucket, os.path.dirname(key))
    
    # Create UserData
    user_data = """\
#!/bin/bash
yum install -y createrepo
aws s3 sync %s /repo --region ap-northeast-1
createrepo --checksum sha /repo
aws s3 sync --exact-timestamps --delete /repo %s --region ap-northeast-1
shutdown -h now
""" % (sync_path, target_path)
    
    # Create Instance
    ec2.run_instances(
        ImageId = image_id,
        MinCount = 1,
        MaxCount = 1,
        InstanceType = 't2.nano',
        UserData = user_data,
        InstanceInitiatedShutdownBehavior='terminate',
        SubnetId = subnet_id,
        IamInstanceProfile = { 'Name': instance_profile_name }
    )