Added first steps

Author: flavienbwk

Dockerfile

@@ -0,0 +1,7 @@
+FROM ubuntu:bionic
+
+RUN apt-get update
+RUN apt-get install python3 python3-pip -y
+
+COPY ./requirements.txt /requirements.txt
+RUN pip3 install -r /requirements.txt

README.md

@@ -1,2 +1,102 @@
-# Docker-gRPC-Python-Example
-An example of a simple gRPC communication in Python built by Docker.
+# gRPC Python Docker example
+
+A simple gRPC communication example in Python built by Docker
+
+In this example, we are going to build a simple gRPC client and server that take an image as input and return a negative and resized version of the image.
+
+## 1. Dockerfile and dependencies
+
+Nothing specific, just pip install the `grpcio` module for gRPC communication and the `numpy` + `Pillow` libraries to manipulate our image.
+
+We are also going to use the `pickle` library (included in Python) to transform our numpy image, read by Pillow, into bytes.
+
+```Dockerfile
+FROM ubuntu:bionic
+
+RUN apt-get update
+RUN apt-get install python3 python3-pip -y
+
+COPY ./requirements.txt /requirements.txt
+RUN pip3 install -r /requirements.txt
+```
+
+Our `requirements.txt` file :
+
+```python-requirements
+numpy==1.19.0
+Pillow==7.2.0
+grpcio==1.30.0
+```
+
+## 2. Defining your proto file
+
+gRPC works with `.proto` files to know which data to handle. Let's create a [`image_transform.proto`](./image_transform.proto) file :
+
+```proto
+syntax = "proto3";
+
+package flavienbwk;
+
+service EncodeService {
+    rpc GetEncode(sourceImage) returns (transformedImage) {}
+}
+
+// input
+message sourceImage {
+    bytes image = 1; // Our numpy image in bytes (by pickle)
+    int32 width = 2; // Width to which we want to resize our image
+    int32 height = 3; // Height to which we want to resize our image
+}
+
+// output
+message transformedImage {
+    bytes image = 1; // Our negative resized image in bytes (by pickle)
+}
+```
+
+## 3. Compile your .proto file
+
+`.proto` files must be compiled with the `grpcio-tools` library to generate two classes that will be used to perform the communication between our client and server
+
+First, install the `grpcio-tools` library :
+
+```console
+pip3 install grpcio-tools
+```
+
+And compile our [`image_transform.proto`](./image_transform.proto) file with :
+
+```console
+python3 -m grpc_tools.protoc -I. --python_out=./grpc_compiled --grpc_python_out=./grpc_compiled image_transform.proto
+```
+
+Files `image_transform_pb2.py` and `image_transform_pb2_grpc.py` files will appear in `grpc_compiled/`
+
+## 4. Client
+
+Our [client.py](./client.py) file reads the image which becomes a numpy array and sends the query to the server along with the resize information. Then we save the image under `eiffel-tower-transformed.jpg`.
+
+```client.py
+from PIL import Image
+import numpy as np
+import pickle
+import grpc
+
+import grpc_compiled.image_transform_pb2
+import grpc_compiled.image_transform_pb2_grpc
+
+def run():
+    channel = grpc.insecure_channel('server:13000')
+    stub = image_transform_pb2_grpc.EncodeServiceStub(channel)
+    image = np.array(Image.open('eiffel-tower.jpg'))
+    query = image_transform_pb2.sourceImage(
+        image=pickle.dumps(image),
+        width=320,
+        height=180
+    )
+    response = stub.GetEncode(query)
+    response.image
+
+if __name__ == "__main__":
+    run()
+```

client.py

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+from PIL import Image
+import numpy as np
+import pickle
+import grpc
+
+import grpc_compiled.image_transform_pb2
+import grpc_compiled.image_transform_pb2_grpc
+
+def run():
+    channel = grpc.insecure_channel('server:13000')
+    stub = image_transform_pb2_grpc.EncodeServiceStub(channel)
+    image = np.array(Image.open('eiffel-tower.jpg'))
+    query = image_transform_pb2.sourceImage(
+        image=pickle.dumps(image),
+        width=320,
+        height=180
+    )
+    response = stub.GetEncode(query)
+    response.image
+
+if __name__ == "__main__":
+    run()

docker-compose.yml

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+version: '3'
+
+services:
+
+    client:
+        build: .
+        command: python3 /usr/app/client.py
+        volumes:
+            - ${PWD}/eiffel-tower.jpg:/usr/app/eiffel-tower.jpg # Our input image
+            - ${PWD}/client.py:/usr/app/client.py
+            - ./grpc_compiled:/usr/app/grpc_compiled
+
+    server:
+        build: .
+        command: python3 /usr/app/server.py
+        volumes:
+            - ${PWD}/eiffel-tower.jpg:/usr/app/eiffel-tower-transformed.jpg # Our output image
+            - ${PWD}/client.py:/usr/app/server.py
+            - ./grpc_compiled:/usr/app/grpc_compiled

eiffel-tower-transformed.jpg

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+# Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
+"""Client and server classes corresponding to protobuf-defined services."""
+import grpc
+
+import image_transform_pb2 as image__transform__pb2
+
+
+class EncodeServiceStub(object):
+    """Missing associated documentation comment in .proto file."""
+
+    def __init__(self, channel):
+        """Constructor.
+
+        Args:
+            channel: A grpc.Channel.
+        """
+        self.GetEncode = channel.unary_unary(
+                '/flavienbwk.EncodeService/GetEncode',
+                request_serializer=image__transform__pb2.sourceImage.SerializeToString,
+                response_deserializer=image__transform__pb2.transformedImage.FromString,
+                )
+
+
+class EncodeServiceServicer(object):
+    """Missing associated documentation comment in .proto file."""
+
+    def GetEncode(self, request, context):
+        """Missing associated documentation comment in .proto file."""
+        context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+        context.set_details('Method not implemented!')
+        raise NotImplementedError('Method not implemented!')
+
+
+def add_EncodeServiceServicer_to_server(servicer, server):
+    rpc_method_handlers = {
+            'GetEncode': grpc.unary_unary_rpc_method_handler(
+                    servicer.GetEncode,
+                    request_deserializer=image__transform__pb2.sourceImage.FromString,
+                    response_serializer=image__transform__pb2.transformedImage.SerializeToString,
+            ),
+    }
+    generic_handler = grpc.method_handlers_generic_handler(
+            'flavienbwk.EncodeService', rpc_method_handlers)
+    server.add_generic_rpc_handlers((generic_handler,))
+
+
+ # This class is part of an EXPERIMENTAL API.
+class EncodeService(object):
+    """Missing associated documentation comment in .proto file."""
+
+    @staticmethod
+    def GetEncode(request,
+            target,
+            options=(),
+            channel_credentials=None,
+            call_credentials=None,
+            compression=None,
+            wait_for_ready=None,
+            timeout=None,
+            metadata=None):
+        return grpc.experimental.unary_unary(request, target, '/flavienbwk.EncodeService/GetEncode',
+            image__transform__pb2.sourceImage.SerializeToString,
+            image__transform__pb2.transformedImage.FromString,
+            options, channel_credentials,
+            call_credentials, compression, wait_for_ready, timeout, metadata)

eiffel-tower.jpg

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+syntax = "proto3";
+
+package flavienbwk;
+
+service EncodeService {
+    rpc GetEncode(sourceImage) returns (transformedImage) {}
+}
+
+// input
+message sourceImage {
+    bytes image = 1; // Our numpy image (read by Pillow) under a bytes representation
+    int32 width = 2; // Width to which we want to resize our image
+    int32 height = 3; // Height to which we want to resize our image
+}
+
+// output
+message transformedImage {
+    bytes image = 1; // Our negative resized image
+}

grpc_compiled/image_transform_pb2.py

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+numpy==1.19.0
+Pillow==7.2.0
+grpcio==1.30.0