Lambda Copy Image from one bucket to another after resize - amazon-web-services

Question

I am receiving images on a S3 bucket. Using a lambda function, I want to resize the images to a thumbnail and copy the thumbnail into another s3 bucket. The following is the code:
import json
import boto3
import ast
from urllib.request import urlopen
import time
from boto3.dynamodb.conditions import Key, Attr
from PIL import Image
s3_client=boto3.client('s3')
s3_res = boto3.resource('s3')
def lambda_handler(event, context):
client = boto3.resource("dynamodb")
tnlBuck = s3_res.Bucket('aivuthumbnail')
for record in event['Records']:
bucket=record['s3']['bucket']['name']
ikey = record['s3']['object']['key']
params = {'Bucket': bucket, 'Key': ikey}
proj = ikey.split('_')[0]
outlet = ikey.split('_')[1]
parameter = ikey.split('_')[2]
dat = ikey.split('_')[3]
table = client.Table("telescopeImageReceipt")
table.put_item(Item={'image':ikey,'project':proj,'outlet':outlet,'parameter':parameter,'date':dat})
url = s3_client.generate_presigned_url(ClientMethod='get_object', Params=params)
with urlopen(url) as conn:
image = Image.open(conn)
MAX_SIZE = (100, 100)
image.thumbnail(MAX_SIZE)
image.copy("Bucket":tnlBuck)
I have changed the last line to various combinations. But nothing works. The lambda function has full access to S3, Dynamodb and Cloudwatch logs.
The following were some of the options I tried and got the error messages:
Option Tried: tnlBuck.copy(image, ikey)
Error : Expecting dictionary formatted: {"Bucket": bucket_name, "Key": key} but got <PIL.JpegImagePlugin.JpegImageFile image
Option Tried: s3_client.copy({"Bucket":tnlBuck, "Key":ikey})
Error: TypeError: copy() missing 2 required positional arguments: 'Bucket' and ‘Key'
Option tried: image.copy({"Bucket":tnlBuck, "Key":ikey})
Error: TypeError: copy() takes 1 positional argument but 2 were given
Other options had more or less similar errors or thrown a syntax error.

Answer 1

You need to use an S3 bucket to copy the image to it and not the PIL Image object.
Your code should be changed to this:
import json
import io
import boto3
import ast
from urllib.request import urlopen
import time
from boto3.dynamodb.conditions import Key, Attr
from PIL import Image
s3_client=boto3.client('s3')
s3_res = boto3.resource('s3')
def lambda_handler(event, context):
client = boto3.resource("dynamodb")
tnlBuck = s3_res.Bucket('aivuthumbnail')
for record in event['Records']:
bucket=record['s3']['bucket']['name']
ikey = record['s3']['object']['key']
params = {'Bucket': bucket, 'Key': ikey}
proj = ikey.split('_')[0]
outlet = ikey.split('_')[1]
parameter = ikey.split('_')[2]
dat = ikey.split('_')[3]
table = client.Table("telescopeImageReceipt")
table.put_item(Item={'image':ikey,'project':proj,'outlet':outlet,'parameter':parameter,'date':dat})
url = s3_client.generate_presigned_url(ClientMethod='get_object', Params=params)
with urlopen(url) as conn:
image = Image.open(conn)
MAX_SIZE = (100, 100)
image.thumbnail(MAX_SIZE)
img_bytes = io.BytesIO()
image.save(img_bytes, format='JPEG')
img_bytes.seek(0)
tnl_bucket.Object(ikey).put(Body=img_bytes.read())
You should use tnl_bucket to create a new object from thumbnailed image bytes.
img_bytes = io.BytesIO()
image.save(img_bytes, format='JPEG')
img_bytes.seek(0)
tnl_bucket.Object(ikey).put(Body=img_bytes.read())
PIL can save to file on path or BytesIO. You need to return to the stream beginning with .seek(0) so it can be read from the start to get bytes for put method.