Lambda - Add handler module

app.py

@@ -32,6 +32,7 @@ class DocumentParserModel:
         onnx.checker.check_model(onnx_model)
         return rt.InferenceSession(model_path)
 
+    # TODO: test with image blob
     def predict_text(self, image_path):
         try:
             with Image.open(image_path) as img_org:

handler.py

@@ -0,0 +1,25 @@
+# Ref. [Deploying a Machine Learning Model to AWS Lambda | TestDriven.io](https://testdriven.io/blog/ml-model-aws-lambda/)
+import logging
+from app import DocumentParserModel
+
+# initialize logger and model during Lambda's cold start
+LOGGER = logging.getLogger()
+LOGGER.setLevel(logging.INFO)
+
+model_path = "captcha.onnx"
+img_size = (32, 128)
+charset = r"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~"
+model = DocumentParserModel(
+    model_path=model_path,
+    img_size=img_size,
+    charset=charset,
+)
+
+
+def lambda_handle(event, context):
+    # Only used to keep the Lambda warm
+    if event.get("source") == "KEEP_LAMBDA_WARM":
+        LOGGER.info("No ML work to do. Just staying warm...")
+        return "Keeping Lambda warm"
+
+    return {"statusCode": 200, "vc": model.predict_text(image_path=event["image_path"])}