docs: Add docker-compose example (GoogleCloudPlatform#143)

Author: di

examples/README.md

@@ -1,5 +1,11 @@
 # Python Functions Frameworks Examples
 
+## Deployment targets
+### Cloud Run
 * [`cloud_run_http`](./cloud_run_http/) - Deploying an HTTP function to [Cloud Run](http://cloud.google.com/run) with the Functions Framework
 * [`cloud_run_event`](./cloud_run_event/) - Deploying a CloudEvent function to [Cloud Run](http://cloud.google.com/run) with the Functions Framework
-* [`cloud_run_cloudevents`](./cloud_run_cloudevents/) - Deploying a [CloudEvent](https://github.com/cloudevents/sdk-python) function to [Cloud Run](http://cloud.google.com/run) with the Functions Framework
+* [`cloud_run_cloudevents`](./cloud_run_cloudevents/) - Deploying a [CloudEvent](https://github.com/cloudevents/sdk-python) function to [Cloud Run](http://cloud.google.com/run) with the Functions Framework
+
+## Development Tools
+* [`docker-compose`](./docker-compose) -
+* [`skaffold`](./skaffold) - Developing multiple functions on the same host using Minikube and Skaffold

examples/docker-compose/Dockerfile

@@ -0,0 +1,17 @@
+# Use the Python base image
+FROM python
+
+# Set a working directory
+WORKDIR /func
+
+# Copy all the files from the local directory into the container
+COPY . .
+
+# Install the Functions Framework
+RUN pip install functions-framework
+
+# Install any dependencies of the function
+RUN pip install -r requirements.txt
+
+# Run the function
+CMD ["functions-framework", "--target=hello", "--debug"]

examples/docker-compose/README.md

@@ -0,0 +1,67 @@
+# Developing functions with Docker Compose
+
+## Introduction
+
+This examples shows you how to develop a Cloud Function locally with Docker Compose, including live reloading.
+
+## Install `docker-compose`:
+https://docs.docker.com/compose/install/
+
+## Start the `docker-compose` environment:
+
+In this directory, bring up the `docker-compose` environment with:
+```
+docker-compose up
+```
+
+You should see output similar to:
+
+```
+Building function
+[+] Building 7.0s (10/10) FINISHED
+ => [internal] load build definition from Dockerfile                 0.0s
+ => => transferring dockerfile: 431B                                 0.0s
+ => [internal] load .dockerignore                                    0.0s
+ => => transferring context: 2B                                      0.0s
+ => [internal] load metadata for docker.io/library/python:latest     0.6s
+ => [1/5] FROM docker.io/library/python@sha256:7a93befe45f3afb6b337  0.0s
+ => [internal] load build context                                    0.0s
+ => => transferring context: 2.11kB                                  0.0s
+ => CACHED [2/5] WORKDIR /func                                       0.0s
+ => [3/5] COPY . .                                                   0.0s
+ => [4/5] RUN pip install functions-framework                        4.7s
+ => [5/5] RUN pip install -r requirements.txt                        1.1s
+ => exporting to image                                               0.4s
+ => => exporting layers                                              0.4s
+ => => writing image sha256:99962e5907e80856af6b032aa96a3130dde9ab6  0.0s
+ => => naming to docker.io/library/docker-compose_function           0.0s
+
+Use 'docker scan' to run Snyk tests against images to find vulnerabilities and learn how to fix them
+Recreating docker-compose_function_1 ... done
+Attaching to docker-compose_function_1
+function_1  |  * Serving Flask app 'hello' (lazy loading)
+function_1  |  * Environment: production
+function_1  |    WARNING: This is a development server. Do not use it in a production deployment.
+function_1  |    Use a production WSGI server instead.
+function_1  |  * Debug mode: on
+function_1  |  * Running on all addresses.
+function_1  |    WARNING: This is a development server. Do not use it in a production deployment.
+function_1  |  * Running on http://172.21.0.2:8080/ (Press CTRL+C to quit)
+function_1  |  * Restarting with watchdog (inotify)
+function_1  |  * Debugger is active!
+```
+function_1  |  * Debugger PIN: 162-882-413
+
+## Call your Cloud Function
+
+Leaving the previous command running, in a **new terminal**, call your functions. To call the `hello` function:
+
+```bash
+curl localhost:8080/hello
+```
+
+You should see output similar to:
+
+```terminal
+Hello, World!
+```

examples/docker-compose/docker-compose.yml

@@ -0,0 +1,8 @@
+version: "3.9"
+services:
+  function:
+    build: .
+    ports:
+      - "8080:8080"
+    volumes:
+      - .:/func

examples/docker-compose/main.py

@@ -0,0 +1,18 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+def hello(request):
+    """Return a friendly HTTP greeting."""
+    return "Hello, World!!!"

examples/docker-compose/requirements.txt

@@ -0,0 +1 @@
+# Add any Python requirements here