container-security

container-security is a skill for Claude Code, Codex from medy-gribkov/arcana. It costs 37 tokens per session (1,124 once invoked), scanned A, original, Apache-2.0.

Guidance for securing container images and the programs running inside containers. It covers vulnerability scanning, smaller base images, non-root users, runtime secrets, software supply-chain checks, and runtime rules.

In plain words
What is it for?
Use it to scan images for known vulnerabilities, harden Dockerfiles, run containers without administrator rights, inject secrets at runtime, verify dependencies and images, and apply runtime security policies.
Why use it?
Container risks can enter during the build and remain in deployed images, especially when images contain vulnerabilities or embedded secrets. This helps identify and reduce those risks before and during deployment.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to scan images for known vulnerabilities, harden Dockerfiles, run containers without administrator rights, inject secrets at runtime, verify dependencies and images, and apply runtime security policies.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/medy-gribkov/arcana/container-security
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add medy-gribkov/arcana --skill container-security
Clone the repo
git clone --depth 1 https://github.com/medy-gribkov/arcana

Made for: Claude Code, Codex.

Its marketplace also offers this one on its own, as the plugin container-security/plugin install container-security after adding the marketplace above.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for container-security

README.md
[![agentmods](https://agentmods.dev/badge/skills/medy-gribkov/arcana/container-security/github.svg)](https://agentmods.dev/skills/medy-gribkov/arcana/container-security)
Your own site
<a href="https://agentmods.dev/skills/medy-gribkov/arcana/container-security"><img src="https://agentmods.dev/badge/skills/medy-gribkov/arcana/container-security/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for container-security

Your own site · 80×15
<a href="https://agentmods.dev/skills/medy-gribkov/arcana/container-security"><img src="https://agentmods.dev/badge/skills/medy-gribkov/arcana/container-security.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 37 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,124 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00037 $0.01124
Opus 5 $0.00018 $0.00562
Sonnet 5 $0.00007 $0.00225
Haiku 4.5 $0.00004 $0.00112

Measured 8d ago against content hash 0640b515acef, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

container-security scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/container-security/SKILL.md · 206 lines

How it starts

The opening of the file, as written. The whole thing — 206 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Image Scanning

Run Trivy before every push. Fail CI on HIGH or CRITICAL vulnerabilities.

trivy image myapp:latest --severity HIGH,CRITICAL --exit-code 1

Use Grype as a second scanner. Different scanners catch different CVEs.

grype myapp:latest --fail-on high

Store scan results as build artifacts for trending.

trivy image myapp:latest --format json --output scan-results.json

Minimal Base Images

Use distroless or scratch for runtime. Multi-stage builds separate build tools from runtime. See references/dockerfile-hardening.md for complete BAD/GOOD Dockerfile patterns for Go, Node.js, and static binaries.

Rootless Containers

Always create a non-root user and switch to it. For distroless, use the built-in nonroot user (UID 65532). See references/dockerfile-hardening.md for rootless patterns.

Secrets Management

BAD: Baking secrets into the image. They persist in layers even if deleted.

FROM node:24-alpine
ENV DATABASE_PASSWORD=supersecret
COPY . /app
CMD ["node", "server.js"]

GOOD: Inject secrets at runtime via environment variables or mounted files.

docker run -e DATABASE_PASSWORD="$(cat /secure/db-password)" myapp:latest

For Kubernetes, use Secrets mounted as volumes or environment variables.

env:
  - name: DATABASE_PASSWORD
    valueFrom:
      secretKeyRef:
        name: db-credentials
        key: password

Build-Time Secrets

Use BuildKit secrets for credentials needed during build (e.g., private registry tokens).

BAD: Copying .env file into the image.

COPY .env /build/.env
RUN npm install --registry=https://private.npm.com

GOOD: Mount secrets during build without persisting them.

# syntax=docker/dockerfile:1
RUN --mount=type=secret,id=npmrc,target=/root/.npmrc \
    npm install --registry=https://private.npm.com

Build with:

docker buildx build --secret id=npmrc,src=.npmrc .

Audit .dockerignore

Read the full file on GitHub · 206 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 206 lines · 37 tokens per session scan A 0640b515acef

Subscribe to this mod's changes

container-security is a skill published in the GitHub repository medy-gribkov/arcana (1 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 37 tokens to every session and 1,124 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.