Docker Compose with Data Persistence Lab

🛠 Lab from the Platform Engineering Bootcamp. Used in Week 7. Bootcamp landing page: https://academy.tekanaid.com/bootcamps/platform-engineering-bootcamp Parent course(s):

• Week 7: Docker Fundamentals (slug: docker-fundamentals)

Build on your TaskFlow fork from the previous Containerize TaskFlow lab. TaskFlow's Compose baseline already wires up PostgreSQL and a real Redis-backed task-list cache, both connected and healthy from the moment you start the stack. Rather than re-adding infrastructure that's already there, this lab has you prove it: break PostgreSQL's named volume on purpose and watch data disappear, then fix it; validate the real Redis cache's population, invalidation, and graceful degradation when Redis goes down; break the backend's health-aware startup dependency and watch it race ahead of a database that isn't there yet, then restore it.

In the final task, you'll tear the whole stack down, bring it back up, prove your data survived, and compare your Compose file against the repo's own original.

By the end of this lab, you'll understand:

• Docker Compose service orchestration with build contexts
• Named volumes for data persistence, and what happens when they're missing
• A real application-level Redis cache: population, invalidation, and graceful degradation
• Service dependencies and health checks (depends_on with condition: service_healthy)
• Docker networking between containers
• Verifying data persistence across a full container teardown and restart