Phase 32 objective: containerize the existing architecture without moving durable state, secrets, or business responsibilities into the container layer.
Build Compile NestJS in a builder stage and run the compiled JavaScript in the runtime stage. The runtime does not need TypeScript or Nest CLI. # Runtime concept FROM node:24-bookworm-slim AS runner ENV NODE_ENV=production WORKDIR /app COPY --from=builder /out/api ./ COPY --from=builder /workspace/apps/api/dist ./dist USER taskflow CMD ["node", "dist/main.js"]
Prisma The generated Prisma client and PostgreSQL adapter must be present in the runtime artifact. Migration tooling is deliberately separated from the API runtime process.
Signals The container should run Node directly as PID 1 so SIGTERM reaches the application. Phase 30 already enabled Nest shutdown hooks for graceful termination.
Containers package a process and its runtime assumptions. The lesson is not memorizing Docker commands; it is making those assumptions repeatable and observable.
Restate the goal of “NestJS API Production Image” as one observable behavior. Write the success signal before touching code.
Trace the boundary map: source + lockfile → build context → image layers → container process → health signal. Mark the one boundary this lesson changes.
Inspect the current repository state and record the exact files, route, table, or runtime involved. Avoid creating an abstraction before you can name the existing owner.
Implement the smallest vertical slice. Add one coherent change, run the narrowest verification command, and read the output before continuing.
Connect the slice to TaskFlow’s phase artifact: Dockerfiles and compose/dev verification that build and run TaskFlow services from clean inputs.. Verify behavior from the outside as a user or API client would.
Create one controlled failure that is safe to reproduce. Predict the symptom first, capture evidence, locate the earliest broken boundary, then fix only that cause.
Close the reference and rebuild or explain the core change from memory. Record what you would monitor or test before trusting the same change in production.
FROM node:24-alpine AS build
WORKDIR /app
RUN corepack enable
COPY package.json pnpm-lock.yaml pnpm-workspace.yaml ./
COPY apps/api/package.json apps/api/package.json
RUN pnpm install --frozen-lockfile
COPY . .
RUN pnpm --filter api buildDo not copy this as a finished answer. Predict what each boundary does, type the smallest useful slice, run it, then compare the result with your prediction.
Inspect container logs and PID 1 command; confirm the process stays in foreground and required config exists.
Check bind address, exposed/published ports, network namespace, and health endpoint.
Without copying the final source, create a second small scenario that applies “NestJS API Production Image” to a different TaskFlow resource or input. Write the acceptance criteria first, implement it, and provide the evidence that each criterion is satisfied.
Add healthcheck/readiness behavior and test startup plus graceful stop.
Use the smallest change that demonstrates this lesson. Stop after it works and capture evidence.Copying .env into image
Predict the symptom before causing the failure. Then locate the earliest boundary where reality diverges from expectation.Why does this responsibility live here, what input does it trust, what output proves success, and what would go wrong if another layer owned it?
If your explanation is vague, repeat the boundary trace before moving on.Close the reference. Reproduce the core idea from memory or explain the exact request/data flow aloud. Then check your diff or notes for accidental shortcuts that bypass validation, authorization, error handling, or verification earned in earlier phases.