├── .gitignore
├── requirements.txt
├── README.md
└── app.py


/.gitignore:
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1 | .chalice
2 | .idea
3 | 


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/requirements.txt:
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1 | boto3==1.3.1
2 | 


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/README.md:
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1 | Sample code for the AWS Lambda blog posts: https://www.mschweighauser.com/create-a-thumbnail-api-service/
2 | 


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/app.py:
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 1 | import base64
 2 | import uuid
 3 | from subprocess import Popen, PIPE
 4 | 
 5 | import boto3
 6 | from chalice import BadRequestError, Chalice
 7 | 
 8 | 
 9 | app = Chalice(app_name='thumbnail-service')
10 | app.debug = True  # TODO: Disable on production
11 | 
12 | S3 = boto3.client('s3')
13 | S3_BUCKET = ''  # TODO: Replace with valid bucket name
14 | 
15 | 
16 | @app.route('/', methods=['POST'])
17 | def index():
18 |     body = app.current_request.json_body
19 | 
20 |     image = base64.b64decode(body['data'])
21 |     format = {'jpg': 'jpeg', 'png': 'png'}[body.get('format', 'jpg').lower()]
22 |     mode = {'max': '', 'min': '^', 'exact': '!'}[body.get('mode', 'max').lower()]
23 |     width = int(body.get('width', 128))
24 |     height = int(body.get('height', 128))
25 | 
26 |     cmd = [
27 |         'convert',  # ImageMagick Convert
28 |         '-',  # Read original picture from StdIn
29 |         '-auto-orient',  # Detect picture orientation from metadata
30 |         '-thumbnail', '{}x{}{}'.format(width, height, mode),  # Thumbnail size
31 |         '-extent', '{}x{}'.format(width, height),  # Fill if original picture is smaller than thumbnail
32 |         '-gravity', 'Center',  # Extend (fill) from the thumbnail middle
33 |         '-unsharp',' 0x.5',  # Un-sharpen slightly to improve small thumbnails
34 |         '-quality', '80%',  # Thumbnail JPG quality
35 |         '{}:-'.format(format),  # Write thumbnail with `format` to StdOut
36 |     ]
37 | 
38 |     p = Popen(cmd, stdout=PIPE, stdin=PIPE)
39 |     thumbnail = p.communicate(input=image)[0]
40 | 
41 |     if not thumbnail:
42 |         raise BadRequestError('Image format not supported')
43 | 
44 |     filename = '{}_{}x{}.{}'.format(uuid.uuid4(), width, height, format)
45 |     S3.put_object(
46 |         Bucket=S3_BUCKET,
47 |         Key=filename,
48 |         Body=thumbnail,
49 |         ACL='public-read',
50 |         ContentType='image/{}'.format(format),
51 |     )
52 | 
53 |     return {
54 |         'url': 'https://s3.amazonaws.com/{}/{}'.format(S3_BUCKET, filename)
55 |     }
56 | 


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