slp-modular-cms/aidlc-docs/features/local-dev-master-slave-setup/construction/plans/unit-2-frontend-dual-instance-tooling-code-generation-plan.md

Code Generation Plan — Unit 2: Frontend Dual-Instance Tooling & Runbook

Unit Context

• Requirements covered: FR-3, FR-4, NFR-3, NFR-4 (see inception/requirements/requirements.md)
• Design source: inception/application-design/component-dependency.md (data-flow diagram), unit-of-work.md
• Dependencies: Unit 1 (Backend dual-instance hosting) — complete and verified (master discovers 3 modules, slave discovers 2, no Master)
• Blocks: Build and Test (final manual verification)
• Workspace root: K:\Development\Projects\SlpModularCms

Steps

• Step 1 — Frontend env files for slave mode

  • Create frontend/.env.slave.local (gitignored via existing frontend/.gitignore *.local pattern — verified via git check-ignore): VITE_API_BASE_URL=https://localhost:7222
  • Modify frontend/.env.example: add a second documented block showing the slave-mode value, alongside the existing master-mode VITE_API_BASE_URL example

• Step 2 — dev:slave npm script

  • Modify frontend/package.json: add "dev:slave": "vite --mode slave --port 5174" to the scripts section. Vite's mode-based env loading will load .env.slave.local when run with --mode slave (Vite loads .env.[mode].local in addition to .env.local; since both files would apply, and .env.local takes precedence per Vite's env-file priority for the same key when both exist for a mode, name the slave file .env.slave.local specifically — this file only loads when --mode slave is passed, so there is no conflict with the default .env.local used by pnpm dev)

• Step 3 — Runbook documentation

  • Modify root README.md: add new section "Lokaal Master + Slave Draaien (Dev)" immediately after the existing "Master CMS Module" section, covering:
    1. Starting the master backend (dotnet run --project src/SlpModularCms.Api --launch-profile https)
    2. Starting the slave backend (dotnet run --project src/SlpModularCms.Api.Slave --launch-profile https), noting it needs its own appsettings.local.json (from appsettings.local.json.example) with a separate local database
    3. Starting the master frontend (pnpm dev, port 5173) and, optionally, the slave frontend (pnpm dev:slave, port 5174)
    4. Using the existing "Add CMS Instance" dialog on the master frontend to register the slave (URL https://localhost:7222) and confirm it shows as connected/healthy
    5. Cross-reference to this feature's requirements doc for anyone wanting the full rationale

• Step 4 — Documentation summary

  • Create aidlc-docs/features/local-dev-master-slave-setup/construction/unit-2-frontend-dual-instance-tooling/code/summary.md documenting what was created/modified

Notes

• No new tests for this unit — it's env/config/docs only, no testable logic.
• Final end-to-end manual verification (actually starting both instances with real local databases, registering the slave, confirming the connection) happens in Build and Test, since it requires a running local SQL Server/localdb the automated agent cannot fully provision headlessly.