ADR-0006: Docker SDK observation and Compose CLI lifecycle

• Status: Accepted
• Date: 2026-07-15

Context

The Docker Engine API is strong for inspection, events, logs, and metrics, but Compose lifecycle semantics also depend on the user’s installed plugin, contexts, credential helpers, and configuration.

Decision

Use the official Docker Go SDK with API negotiation for observation and live streams. Use the installed docker compose CLI for normalized configuration and lifecycle execution. Identify projects and services through canonical Compose labels, never container-name prefixes.

Consequences

Switchyard matches commands users already trust while retaining typed observation. Command building, execution, config reading, event watching, logs, metrics, and reconciliation remain focused collaborators. Docker failure cannot disable non-Docker project behavior.