Docker Local Development

Run this skill in the main conversation. Do not spawn subagents, agent teams, or delegated parallel workers unless the user explicitly approves the proposed count and scope after being told that doing so can increase usage. Ask again before expanding an approved scope.

Guardrails

• Design for local development. Keep production images, secrets, deployment, certificates, and runtime topology separate.
• Inspect before asking questions or proposing services. Treat detection as evidence, not authority.
• Ask only about unresolved choices that materially change the result. Group related questions and recommend a default; do not force a fixed questionnaire.
• Preserve existing Docker files and unrelated working-tree changes. Show a semantic diff before replacing or materially restructuring a working stack. Never commit, reset, delete volumes, run migrations or seeds, or overwrite files unless the user authorized that action.
• Generate only services the project uses or the user explicitly requests. A database is not mandatory when the project uses SQLite, a host service, or an external database.
• Prefer direct foreground commands and one concern per service. Add Supervisor or PM2 only when the project already requires it or production-parity testing justifies it.
• Prefer a stable top-level Compose name: and role-based service names. Do not set container_name by default because it prevents service scaling and creates cross-project collisions.
• Select images by project constraints, team or production compatibility, trusted publisher, supported version, and architecture. Treat an already-downloaded image only as a tie-breaker. Avoid floating latest tags in generated files.
• Publish only ports needed by the host. Bind local-only ports to 127.0.0.1 by default; keep databases, caches, SMTP, PHP-FPM, and internal APIs unexposed when possible.
• Keep secrets out of committed files, generated documentation, command output, and frontend or proxy containers. Generate an ignored local env file plus a safe example when configuration is needed.