Phase G: Containers, Networking, and Delivery (In-Repo Lessons)

Maps to: Blueprint Phase G

Goal: Run the same stack locally and in deployment with reproducible images, compose files, and a reverse proxy at the edge.

Table of Contents

• Lesson 1: Images vs containers
• Lesson 2: Volumes and configuration
• Lesson 3: Multi-service Compose
• Lesson 4: Nginx as reverse proxy
• Lesson 5: Makefiles and developer ergonomics
• Exercises
• Next step

Lesson 1: Images vs containers

An image is a filesystem snapshot + metadata. A container is a running instance.

Rebuild images when dependencies change; bump tags for anything deployed.

Lesson 2: Volumes and configuration

• Volumes persist database data across container restarts
• Bind mounts help local dev hot reload
• .env files should not be baked into public images

Lesson 3: Multi-service Compose

Compose links services on a shared network. Define explicit dependencies and healthchecks so APIs do not start before the database is ready.

Lesson 4: Nginx as reverse proxy

Nginx can terminate TLS (in production), route paths to services, and serve static assets.

At minimum, learn:

• proxy_pass
• headers like Host and X-Forwarded-For (trust carefully)

Lesson 5: Makefiles and developer ergonomics

Short commands (make dev, make test) reduce onboarding friction and match CI commands.

Exercises

1. Compose api + db + web with a private network and published ports only where needed.
2. Add a healthcheck endpoint and wire it into Compose health dependencies.
3. Put Nginx in front of two API replicas and document how you would test load balancing locally.

Next step

Phase H: AI integration