Add Docker compose example (#7)

.github/workflows/ci.yaml

@@ -54,5 +54,10 @@ jobs:
           docker load --input /tmp/uv-docker-example.tar
           docker image ls -a
 
-      - name: Test image
-        run: ./run.sh
+      - name: Test command line
+        run: ./run.sh hello
+
+      - name: Test Docker compose
+        run: |
+          docker compose up --watch -d
+          docker compose down

Dockerfile

@@ -19,5 +19,7 @@ RUN uv sync --frozen
 # Place executables in the environment at the front of the path
 ENV PATH="/app/.venv/bin:$PATH"
 
-# Set the default command to the application
-CMD ["hello"]
+# Run the FastAPI application by default
+# Uses `fastapi dev` to enable hot-reloading when the `watch` sync occurs
+# Uses `--host 0.0.0.0` to allow access from outside the container
+CMD ["fastapi", "dev", "--host", "0.0.0.0", "src/uv_docker_example"]

README.md

@@ -11,19 +11,27 @@ A [`run.sh`](./run.sh) utility is provided for quickly building the image and st
 This script demonstrates best practices for developing using the container, using bind mounts for
 the project and virtual environment directories.
 
-To run the application in the container:
+To build and run the web application in the container using `docker run`:
 
 ```console
 $ ./run.sh
 ```
 
-To run the application in the container, checking if the environment is up-to-date first:
+Then, check out [`http://localhost:8000`](http://localhost:8000) to see the website.
+
+To build and run the web application using Docker compose:
+
+```
+docker compose up --watch 
+```
+
+To run the command-line entrypoint in the container:
 
 ```console
-$ ./run.sh uv run hello
+$ ./run.sh hello
 ```
 
-To check that the environment is up-to-date:
+To check that the environment is up-to-date after image builds:
 
 ```console
 $ ./run.sh uv sync --frozen
@@ -63,13 +71,20 @@ mounts during container runs.
 The [`run.sh`](./run.sh) script includes an example of invoking `docker run` for local development,
 mounting the source code for the project into the container so that edits are reflected immediately.
 
+### Docker compose file
+
+The [compose.yml](./compose.yml) file includes a Docker compose definition for the web application.
+It includes a [`watch`
+directive](https://docs.docker.com/compose/file-watch/#compose-watch-versus-bind-mounts) for Docker
+compose, which is a best-practice method for updating the container on local changes.
+
 ### Application code
 
 The Python application code for the project is at
-[`src/uv_docker_example/__init__.py`](./src/uv_docker_example/__init__.py) — it just prints hello
-world.
+[`src/uv_docker_example/__init__.py`](./src/uv_docker_example/__init__.py) — there's a command line
+entrypoint and a basic FastAPI application — both of which just display "hello world" output.
 
 ### Project definition
 
-The project at [`pyproject.toml`](./pyproject.toml) includes includes Ruff as an example development
-dependency and defines a `hello` entrypoint for the application.
+The project at [`pyproject.toml`](./pyproject.toml) includes Ruff as an example development
+dependency, includes FastAPI as a dependency, and defines a `hello` entrypoint for the application.

compose.yml

@@ -0,0 +1,25 @@
+services:
+  web:
+    # Build the image from the Dockerfile in the current directory
+    build: .
+
+    # Host the FastAPI application on port 8000
+    ports:
+      - "8000:8000"
+
+    develop:
+      # Create a `watch` configuration to update the appl
+      # https://docs.docker.com/compose/file-watch/#compose-watch-versus-bind-mounts
+      watch:
+        # Sync the working directory with the `/app` directory in the container
+        - action: sync
+          path: .
+          target: /app
+          # Exclude the project virtual environment — it could be for a
+          # different platform in the container
+          ignore:
+            - .venv/
+
+        # Rebuild the image on changes to the `pyproject.toml`
+        - action: rebuild
+          path: ./pyproject.toml

pyproject.toml

@@ -4,7 +4,9 @@ version = "0.1.0"
 description = "Add your description here"
 readme = "README.md"
 requires-python = ">=3.11"
-dependencies = []
+dependencies = [
+    "fastapi>=0.112.2",
+]
 
 [build-system]
 requires = ["hatchling"]
@@ -16,4 +18,5 @@ hello = "uv_docker_example:hello"
 [tool.uv]
 dev-dependencies = [
     "ruff>=0.6.2",
+    "fastapi-cli>=0.0.5",
 ]

run.sh

@@ -9,6 +9,7 @@
 #   --rm                        Remove the container after exiting
 #   --volume .:/app             Mount the current directory to `/app` so code changes don't require an image rebuild
 #   --volume /app/.venv         Mount the virtual environment separately, so the developer's environment doesn't end up in the container
+#   --expose                    Expose the web server port 8000 to the host
 #   -it $(docker build -q .)    Build the image, then use it as a run target
 #   $@                          Pass any arguments to the container
 
@@ -22,6 +23,7 @@ docker run \
     --rm \
     --volume .:/app \
     --volume /app/.venv \
+    --publish 8000:8000 \
     $INTERACTIVE \
     $(docker build -q .) \
     "$@"

src/uv_docker_example/__init__.py

@@ -1,2 +1,12 @@
+from fastapi import FastAPI
+
+app = FastAPI()
+
+
 def hello() -> str:
-    print("Hello from uv-docker-example!")
+    print("Hello world")
+
+
+@app.get("/")
+async def root():
+    return "Hello world"