How to trigger lambda function using SNS?

Question

Heyy,

I want to trigger my lambda function when i am uploading an image to S3 bucket. After successful upload on S3 i want to trigger my Lambda function on the callback. Can you please help me how to achieve that?

Answer 1

You need to set up a Lambda to trigger from an object creation event within S3, link here - https://docs.aws.amazon.com/AmazonS3/latest/user-guide/enable-event-notifications.html

You will also need to configure the correct IAM permission roles for your Lambda function and S3, a good link for that is here https://docs.amazonaws.cn/en_us/lambda/latest/dg/with-s3-example.html

Here is some code to get you started on the implementation -

    import urllib
    import boto3

    s3 = boto3.client('s3')

    def lambda_handler(event, context):
            bucket = event['Records'][0]['s3']['bucket']['name']
            key = urllib.parse.unquote_plus(event['Records'][0]['s3']['object']['key'], encoding='utf-8')
            response = s3.get_object(Bucket=bucket, Key=key)

This will get the uploaded file, and store it in response. What you want to do from here, is up to you.