patch-s3-bucket.py

#!/usr/bin/env python3
import boto3
import gzip
import sys
import mimetypes
from pprint import pprint
from typing import Dict, Any

mimetypes.add_type('application/wasm', '.wasm')
mimetypes.add_type('text/markdown', '.md')

s3 = boto3.resource('s3')

bucket = s3.Bucket(sys.argv[1])

for obj_sum in bucket.objects.filter(Prefix=sys.argv[2]):
	# Skip folders
	if obj_sum.size == 0:
		continue

	obj = obj_sum.Object()
	
	update: Dict[str,Any] = dict()

	print(obj.key)
	
	data = obj.get()
	if obj.content_encoding != 'gzip':
		print(f"Uncompressed {data['ContentLength']}")
		compressed = gzip.compress(data['Body'].read())
	else:
		compressed = data['Body'].read()
	print(f"Compressed   {len(compressed)}")
	update['Body'] = compressed
	update['ContentEncoding'] = 'gzip'

	content_type, _ = mimetypes.guess_type(obj.key)
	print(f"Content-Type: {content_type}")
	update['ContentType'] = content_type or 'binary/octet-stream'

	if update and 'Body' in update:
		obj.put(**update)