Dockerfile Audit

Hadolint-grade Dockerfile audit as an MCP server. 18+ checks across 5 categories, every finding ships with severity, line number, remediation text, and a copy-paste Dockerfile snippet.

Built by Unbearable Labs. Pay-per-event pricing — only billed when a tool is actually called.

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Available on

• Apify Actor Store — primary, metered usage (PPE)
• MCPize — pending submission
• MCP.so — pending submission
• PulseMCP — pending submission
• Smithery — pending submission
• Glama — pending submission

Newsletter: Unbearable TechTips Weekly · All Actors: github.com/UnbearableDev

What it does

Point any MCP-capable client (Claude Desktop, Cursor, n8n, Make, Zapier, custom agents) at this server, hand it a Dockerfile, get back a structured report:

• Severity — high / medium / low / info
• Line number — exact location in the file
• Description — what's wrong and why it matters
• Remediation — what to do about it
• Fix snippet — Dockerfile syntax you can paste directly

Tools

Tool	Purpose
audit_dockerfile(dockerfile_content? | dockerfile_url?, min_severity='low')	Run all checks
check_base_image(...)	FROM/tag/digest/registry checks only
check_instructions(...)	CMD form, ADD vs COPY, MAINTAINER, etc.
check_security(...)	USER, sudo, chmod 777, curl|bash, hardcoded secrets, HEALTHCHECK
check_efficiency(...)	apt cache hygiene, pip caching
check_secrets(...)	ARG with secret-pattern names
list_checks(category?)	Browse the full check catalog

Provide exactly one of dockerfile_content (paste the file) or dockerfile_url (HTTPS URL — e.g. GitHub raw).

Check catalog (v1: 18 checks across 5 categories)

ID	Category	Severity	Title
DFA-001	base_image	medium	Image uses :latest tag or no tag
DFA-002	base_image	info	No SHA256 digest pin on FROM
DFA-003	base_image	medium	Untrusted registry
DFA-010	instructions	low	CMD in shell form
DFA-011	instructions	low	ENTRYPOINT in shell form
DFA-012	instructions	info	MAINTAINER instruction is deprecated
DFA-013	instructions	medium	ADD used where COPY would suffice
DFA-020	security	medium	No USER directive (runs as root)
DFA-021	security	high	USER root set explicitly
DFA-022	security	high	sudo invoked in RUN
DFA-023	security	high	chmod 777 in RUN
DFA-024	security	medium	curl|bash pattern in RUN
DFA-025	security	high	Hardcoded secret in ENV
DFA-027	security	low	No HEALTHCHECK
DFA-030	efficiency	low	apt-get update without install
DFA-031	efficiency	low	apt-get install without --no-install-recommends
DFA-032	efficiency	low	pip install without --no-cache-dir
DFA-040	secrets	medium	ARG with secret-pattern name

Use list_checks to get the canonical, up-to-date catalog.

Pricing

Event	USD
Any audit / check_* tool call	$0.02
list_checks discovery	$0.005

Example response (truncated)

{
  "summary": {
    "total_findings": 6,
    "by_severity": {"high": 2, "medium": 2, "low": 2, "info": 0}
  },
  "findings": [
    {
      "id": "DFA-021",
      "category": "security",
      "severity": "high",
      "instruction": "USER",
      "line_number": 3,
      "title": "USER root set explicitly",
      "description": "...",
      "remediation": "Switch to a non-root UID after any root-required RUN steps.",
      "fix_dockerfile_snippet": "USER 10001:10001",
      "references": ["CIS-Docker-4.1"]
    }
  ]
}

Connecting from Claude Desktop

{
  "mcpServers": {
    "dockerfile-audit": {
      "transport": "streamable-http",
      "url": "https://YOUR-ACTOR-URL.apify.actor/mcp"
    }
  }
}

Limits

• Dockerfile size: 200 KB cap per audit
• URL fetch: 5s timeout, max 3 redirects, HTTPS only
• Session timeout: 5 minutes of inactivity

What's NOT covered (yet)

• Live image vulnerability scanning (use Trivy / Grype for that)
• Multi-stage build optimization analysis (DFA-004 / DFA-005 — roadmapped)
• Compose-file audit (separate MCP: docker-compose-audit)

Sibling MCPs from Unbearable Labs

• docker-compose-audit — same pattern for docker-compose.yml
• hu-postcode-validator — Hungarian postcode lookup

Source / contact

Issues and ideas: [email protected] or the GitHub org UnbearableDev.