A quick and merry lab on S3 and Lambda – nice and easy

Services Covered

•  S3
•  Lambda

Lab description

Upload a Christmas tree into S3 bucket and let Lambda do it’s .

Learning Objectives

• Create amazing Lambda
• Send Christmas tree
• Let Events call the Lambda and do the magic

Lab date

24-12-2021

Prerequisites

AWS account

Lab steps

1. Create a S3 :snowman: bucket.

   

2. Create a Lambda function with Python as runtime.

   import os, zipfile
   from io import BytesIO
   import boto3
   
   s3 = boto3.client('s3')
   
   def lambda_handler(event, context):
   
      # read bucket and key from event data
      record = event['Records'][0]['s3']
      bucket = record['bucket']['name']
      key = record['object']['key']
   
      # generate new key name
      new_key = "zip/%s.zip" % os.path.basename(key)
   
      # read the source obj content
      body = s3.get_object(Bucket=bucket, Key=key)['Body'].read()
   
      # create new obj with compressed data
      s3.put_object(
          Body=compress(body, key),
          Key=new_key,
          Bucket=bucket,
      )
   
      return "OK"
   
   def compress(body, key):
      data = BytesIO()
      with zipfile.ZipFile(data, 'w', zipfile.ZIP_DEFLATED) as f:
          f.writestr(os.path.basename(key), body)
      data.seek(0)
      return data.read()

3. :santa:Add trigger and select S3.
4. :santa:In your S3 bucket create a folder called images.Then upload a file to that folder.

   

   This will invoke a Lambda function and create a new folder called zip with output file:

   

Lab files

Acknowledgements

• cloud academy