# Ops Docker Foundations > Mastering the container lifecycle and professional Dockerfile creation. Use when this capability is needed. - Skill: `tomevault-io/ops-docker-foundations` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/ops-docker-foundations` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/ops-docker-foundations/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: DevOps & Infra - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/ops-docker-foundations --- # Docker Foundations Containers provide consistent environments across development and production. ## Image Layers - **Caching**: Structure your `Dockerfile` to put static layers (like OS updates) at the top and changing layers (code) at the bottom to speed up rebuilds. - **Images vs Containers**: An image is the blueprint; a container is the running instance. ## Professional Dockerfile - **Base Images**: Use official, minimal images (e.g., `python:3.11-slim`). - **Commands**: Master `RUN`, `COPY`, `WORKDIR`, `EXPOSE`, and `CMD`/`ENTRYPOINT`. ## Best Practices - **Single Responsibility**: One service per container. - **.dockerignore**: Exclude `node_modules`, `venv`, and `.git` to keep images small and secure. --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/jcorpac) — claim your Tome and manage your conversions.