ADR 6: Docker-First Local Development Platform

Status: Accepted

Context

The boot orchestrator, health checks, Helm installs, and REST API handlers need testing without cloud credentials. Developers also need a fast local development experience. Three options:

1. Cloud-first: Build OCI platform, test with real credentials.
2. Mock-first: Build against interfaces with mock implementations.
3. Docker-first: Build a Docker platform that runs Talos in containers locally.

Decision

Implement the Docker platform first. rezusctl boot --platform docker creates a local Talos cluster in Docker containers, installs Cilium, and deploys the management plane. This validates the entire orchestration pipeline without cloud credentials.

Consequences

• Full end-to-end testing on any machine with Docker. No cloud account needed.
• Talos in Docker has limitations: no upgrade, no reset, no VIP support on macOS.
• Docker containers are not real VMs — some Talos features won't work (disk management, hardware detection).
• The Docker platform validates orchestration logic. Cloud-specific logic still needs cloud credentials to test.
• Docker containers use USERDATA env var for config, not SideroLink (same-network shortcut).