AWS Lambda function that optimizes images uploaded to a S3 bucket using Kraken.io's API.

README.md

Lambda S3 Kraken

Trigger

• Event type: ObjectCreated
• Suffix: jpg

Environment variables

• AWS_KEY
• AWS_SECRET
• KRAKEN_SECRET
• KRAKEN_KEY

IAM user with access key

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Action": [
                "s3:PutObject",
                "s3:PutObjectAcl"
            ],
            "Effect": "Allow",
            "Resource": "arn:aws:s3:::BUCKET-NAME/*"
        }
    ]
}

IAM role for Lambda

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "logs:CreateLogGroup",
                "logs:CreateLogStream",
                "logs:PutLogEvents"
            ],
            "Resource": "arn:aws:logs:*:*:*"
        },
        {
            "Effect": "Allow",
            "Action": "s3:GetObject",
            "Resource": "arn:aws:s3:::BUCKET-NAME/*"
        }
    ]
}

function.py

from __future__ import print_function

import os
import json
import urllib
import urllib2
import boto3

s3 = boto3.client('s3')

def lambda_handler(event, context):
    bucket = event['Records'][0]['s3']['bucket']['name']
    key = urllib.unquote_plus(event['Records'][0]['s3']['object']['key']).decode('utf8')

    try:
        head = s3.head_object(Bucket=bucket, Key=key)

        if head['Metadata'].has_key('kraked'):
            print('Stopped. Image already optimized: ' + key)
            return
    except:
        print('HEAD request unsuccessful: ' + key)
    
    params = {
        'auth': {
            'api_key': os.environ['KRAKEN_KEY'],
            'api_secret': os.environ['KRAKEN_SECRET']
        },
        'url': 'https://BUCKET-NAME.s3-REGION.amazonaws.com/' + key,
        's3_store': {
            'key': os.environ['AWS_KEY'],
            'secret': os.environ['AWS_SECRET'],
            'region': 'us-east-1',
            'bucket': 'BUCKET-NAME',
            'path': key,
            'metadata': {
                'kraked': 'yes'
            }
        },
        'wait': True,
        'lossy': False
    }

    url = 'https://api.kraken.io/v1/url'

    try:
        data = json.dumps(params)
        request = urllib2.Request(url, data, {'Content-Type': 'application/json'})
        response = urllib2.urlopen(request)
        jsonRes = json.loads(str(response.read()))

        if (jsonRes['success']):
            print('Success. Optimized image: ' + jsonRes['kraked_url'])
        else:
            print('Failed. Error message: ' + jsonRes['message'])

    except Exception as e:
        print(e)
        print('Error optimizing object: ' + key)
        raise e