docker-expert (sickn33): a skill that reviews and fixes Dockerfiles, Compose and image size

docker-expert makes your agent inspect your Docker setup and fix builds, image size, container security and Compose configuration.

Installs: 27.4K; on skills.sh
Stars: 49K; on GitHub
Updated: Nov 2026; last repo commit

The agent starts by detecting your Docker setup: the Docker version, daemon info, Dockerfiles, Compose files, .dockerignore, and running containers and images. It then classifies the problem and applies a fix from six areas: multi-stage builds, security hardening, Compose orchestration, image size, dev workflow and resource limits. It also has a code review checklist and a list of common symptoms with causes.

It tells the agent to inspect before it executes. It should not start your app or publish an image just to check syntax, and a missing tool is not a pass. Validation commands such as docker build --no-cache, docker run and docker scout run only after the agent has reviewed the Dockerfile and you have authorized build side effects. The skill is one SKILL.md and bundles no scripts.

Good for

Developers with a slow, huge or failing Docker build
Teams hardening containers: non-root users, secrets, healthchecks
Anyone setting up Docker Compose for dev and production

Install docker-expert

Claude Code

Copy this prompt.

Install the docker-expert skill in Claude Code. Run this command:

npx skills add https://github.com/sickn33/agentic-awesome-skills --skill docker-expert

Then check that it loaded and tell me how to use it.

2
Paste it into Claude Code. It shows the change and asks before running it.

Requires Node.js.

From its listing on skills.sh. Source.

What's in the skill

When it loads

You are an advanced Docker containerization expert with comprehensive, practical knowledge of container optimization, security hardening, multi-stage builds, orchestration patterns, and production deployment strategies based on current industry best practices.

Sections in SKILL.md

Execution Scope
When invoked:
Core Expertise Areas
1. Dockerfile Optimization & Multi-Stage Builds
2. Container Security Hardening
3. Docker Compose Orchestration
4. Image Size Optimization
5. Development Workflow Integration
6. Performance & Resource Management
Advanced Problem-Solving Patterns
Cross-Platform Builds
Build Cache Optimization
Secrets Management
Health Check Strategies
Code Review Checklist
Dockerfile Optimization & Multi-Stage Builds

Key facts

Author: sickn33 (agentic-awesome-skills, a community collection)
Source label: SKILL.md frontmatter: source community, category devops, risk critical
Repo: sickn33/agentic-awesome-skills, path skills/docker-expert
Installs on skills.sh: 27,353 (as of Nov 2, 2026)
GitHub stars: 48,978 (shared repo, Nov 2, 2026)
License: MIT
Last repo commit: Nov 1, 2026
skills.sh audits: Gen Agent Trust Hub: pass. Socket: pass. Snyk: pass.
Files: 1: SKILL.md only

What it includes

Inspect first, do not run or publish just to validate
Record build, scan and runtime results separately. A missing tool is not a passing check.
Execution scope
Docker version, info, context, Dockerfiles, Compose files, containers and images
Prefers Read, Grep and Glob, with shell commands as fallbacks. Runs docker ps and docker images.
Runs code · Environment detection
docker build --no-cache, docker history, docker scout, docker compose config
Only after reviewing the Dockerfile and authorizing build side effects. Runtime checks run only when requested, in an isolated context.
Runs code · Validation
Layer caching, .dockerignore, base image choice
Alpine, distroless or scratch, with a multi-stage example.
Write · 1. Dockerfile and multi-stage builds
Non-root users, secrets, minimal images, capability limits
Covers BuildKit secret mounts and says never to print or persist a secret in a layer.
Write · 2. Security hardening
Health-gated dependencies, networks, secrets, volumes
Example with an internal backend network and file-based secrets.
Write · 3. Compose orchestration
Distroless, artifact copying, hot reload, debug ports
The dev example binds the debug port to 127.0.0.1.
Write · 4. Image size and 5. Dev workflow
CPU and memory limits, restart policy
Notes that reservations and restart policies depend on the orchestrator.
Write · 6. Performance and resources
Cross-platform builds, build cache, secrets, healthchecks
The multi-arch example uses docker buildx build with --push.
Runs code · Advanced patterns
Six checklists and five symptom guides
Slow builds, vulnerabilities, large images, networking and dev workflow problems.
Review checklist and diagnostics
Recommends other skills for Kubernetes, CI, cloud and databases
Names kubernetes-architect, github-actions-templates, deployment-engineer and database-admin.
Hand-offs

From the official docs

Permissions

High risk

It runs docker commands that build images, run containers and call the network, and its examples include pushing an image. Approve each build or run, and never let it publish to a registry unprompted.

What it can do

Read your data
Create and change things
Delete things
Read-only mode

Watch out for

Docker builds run code and use the network
The SKILL.md frontmatter marks the skill risk: critical, and the text warns that builds execute code and can access the network. Check the Dockerfile and build context first, and approve builds yourself. github.com
It can start containers on your Docker daemon
Validation includes docker run and docker exec. SKILL.md says to do this only when requested, in an isolated context, with resource limits and cleanup, and to stop only containers the task created. github.com
An example pushes an image
The multi-architecture example uses docker buildx build with --push, which publishes to a registry. Do not run it unless you mean to publish. github.com
Secrets can leak through Compose output
SKILL.md tells the agent to avoid printing interpolated secrets from docker compose config and to keep .env and private files out of the build context. github.com

Technical details

Talks to	Registries and package sources your Dockerfile pulls from during a build. Docker Scout scan service when docker scout runs. A registry, only if you run the --push example
Scopes	Local Docker daemon

Questions

What does docker-expert do?

It makes your agent inspect your Dockerfiles and Compose files and fix problems with builds, image size, security, healthchecks and networking, using a built-in checklist and patterns.

How do I install it in Claude Code?

Use the install command in the box above. The skill is one file and needs no other skills.

Will it run docker build on my machine?

Only after it has reviewed the Dockerfile and you have authorized build side effects. SKILL.md says not to start an app or publish an image just to validate syntax.

Is it safe?

Its frontmatter marks the risk as critical, and it runs docker build, run and scan commands against your daemon. Read each command, work in a throwaway context and never let it push to a registry unprompted. It bundles no scripts.

Does it cover Kubernetes or CI?

No. SKILL.md tells the agent to recommend other skills for Kubernetes, GitHub Actions, cloud container services and complex databases, and to stop. Those skills are separate and optional.

Does it need Docker installed?

It checks for Docker first and prints a message if it is missing. SKILL.md says a missing tool is not a passing check, so results are reported as skipped.

Does it work in Codex or Cursor?

The repo README lists Claude Code, Codex, Cursor, Gemini CLI and other agents as targets for its skills. SKILL.md itself names no client.

Information

updated Nov 2, 2026

Repository: sickn33/agentic-awesome-skills
Folder: skills/docker-expert

sickn33/agentic-awesome-skills skills.sh

Sources

Docs, issue trackers and discussions this page is built from.

Show all 2

SKILL.md · github.com
agentic-awesome-skills README · github.com