Docker compose with an nginx proxy for a Python app

compose.yaml

# Nginx will listen on localhost:8080, serving static assets and doing gzip compression.
services:

  app:
    image: python:3.13-alpine
    ports: ["8000:8000"]
    command: ["python", "-m", "http.server"]

  nginx:
    build:
      dockerfile: nginx.dockerfile
    ports: ["8080:8080"]
    environment:
      PORT: "8080"
      APP_PORT: "8000"
      APP_HOST: "app"

nginx-default.conf.template

# Nginx server configuration.
server {
    listen ${PORT};
    gzip on;
    gzip_types
        application/atom+xml
        application/javascript
        application/json
        application/rss+xml
        application/vnd.ms-excel
        application/xml
        image/svg+xml
        image/jpeg
        image/gif
        image/png
        image/webp
        text/css
        text/html
        text/plain
        text/xml
        ;

    location / {
        root /usr/share/nginx/html;
        index index.html;
        try_files $uri $uri/ @app;
    }

    location @app {
        proxy_pass http://${APP_HOST}:${APP_PORT};
    }
}

nginx.dockerfile

# A custom nginx image including our static assets. This (mostly) works when running
# in Cloud Run, with $PORT usually provided as "8000", but with sidecar containers
# listening on 127.0.0.1 (which is different to Docker compose, where services have
# their own service name on a shared network).
FROM nginx:1.28-alpine

ENV APP_PORT=8000
ENV APP_HOST=127.0.0.1
ENV PORT=80
RUN rm /usr/share/nginx/html/index.html
COPY nginx-default.conf.template /etc/nginx/templates/default.conf.template
COPY static /usr/share/nginx/html/