[WIP] Implement an example that resizes images and stores into S3

.gitignore

@@ -1,4 +1,3 @@
-
 # Created by https://www.gitignore.io/api/osx,linux,python,windows,pycharm,visualstudiocode
 
 ### Linux ###
@@ -242,3 +241,10 @@ $RECYCLE.BIN/
 */build/*
 
 # End of https://www.gitignore.io/api/osx,linux,python,windows,pycharm,visualstudiocode
+
+
+## serverless/emailImageResizer
+serverless/emailImageResizer/.chalice/config.json
+serverless/emailImageResizer/.chalice/deployed
+serverless/emailImageResizer/.chalice/deployments
+serverless/emailImageResizer/requirements.txt

serverless/emailImageResizer/.chalice/config.json.tmpl

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+{
+  "version": "2.0",
+  "app_name": "emailImageResizer",
+  "autogen_policy": false,
+  "iam_policy_file": "policy.json",
+  "stages": {
+    "dev": {
+      "api_gateway_stage": "api",
+      "environment_variables": {
+        "PIXEL_RESIZE_TO": "",
+        "S3_BUCKET_NAME": "",
+        "S3_SOURCE_PREFIX": "",
+        "S3_DESTINATION_PREFIX": ""
+      }
+    }
+  }
+}

serverless/emailImageResizer/.chalice/policy.json

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+{
+    "Version": "2012-10-17",
+    "Statement": [
+        {
+            "Effect": "Allow",
+            "Action": [
+                "s3:PutObject",
+                "s3:GetObject"
+            ],
+            "Resource": [
+                "arn:aws:s3:::*"
+            ]
+        },
+        {
+            "Effect": "Allow",
+            "Action": [
+                "logs:CreateLogGroup",
+                "logs:CreateLogStream",
+                "logs:PutLogEvents"
+            ],
+            "Resource": "arn:aws:logs:*:*:*"
+        }
+    ]
+}

serverless/emailImageResizer/README.md

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+# emailImageResizer
+
+TODO: Add more detailed information
+
+## Configuration
+
+```sh
+$ cp .chalice/config.json.tmpl .chalice/config.json
+$ vim .chalice/config.json
+```
+
+## Deployment
+
+```sh
+$ poetry export -f requirements.txt -o requirements.txt --without-hashes
+$ chalice deploy
+```

serverless/emailImageResizer/app.py

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+import email
+import io
+import os
+
+from PIL import Image, ImageFile
+
+import boto3
+from chalice import Chalice
+from chalice.app import S3Event
+
+S3_BUCKET_NAME = os.environ['S3_BUCKET_NAME']
+S3_SOURCE_PREFIX = os.environ['S3_SOURCE_PREFIX']
+S3_DESTINATION_PREFIX = os.environ['S3_DESTINATION_PREFIX']
+PIXEL_RESIZE_TO = int(os.environ['PIXEL_RESIZE_TO'])
+RESIZE_SCALE = PIXEL_RESIZE_TO, PIXEL_RESIZE_TO
+
+ImageFile.LOAD_TRUNCATED_IMAGES = True
+
+
+app = Chalice(app_name='emailImageResizer')
+s3 = boto3.resource('s3')
+s3_bucket = s3.Bucket(S3_BUCKET_NAME)
+
+
+@app.on_s3_event(bucket=S3_BUCKET_NAME, prefix=S3_SOURCE_PREFIX)
+def resize_image(event: S3Event) -> None:
+    content = s3_bucket.Object(event.key).get()
+    message = email.message_from_bytes(content['Body'].read())
+
+    for m in message.get_payload():
+        if not m.get_content_maintype() == 'image':
+            continue
+
+        src_image = io.BytesIO(m.get_payload(decode=True))
+        dst_image = io.BytesIO()
+
+        with Image.open(src_image) as img:
+            img.thumbnail(RESIZE_SCALE)
+            img.save(dst_image, format=img.format)
+
+        s3_bucket.put_object(
+            Key=f'{S3_DESTINATION_PREFIX}{m.get_filename()}',
+            Body=dst_image.getvalue(),
+            ContentType=m.get_content_type(),
+        )