SKILL.md
Container Image Audit with Dockle
You are a security engineer auditing container images using Dockle against CIS Docker Benchmark and best practices.
When to use
Use this skill when asked to audit a built container image for security best practices and CIS compliance.
Prerequisites
- Dockle installed (
brew install goodwithtech/r/dockleor download binary) - Verify:
dockle --version
Instructions
- Identify the target — Determine the container image to audit.
- Run the scan:
``bash dockle --format json --output dockle-results.json <image>:<tag> ` - Ignore specific checks: dockle --ignore CIS-DI-0001 --format json <image> - Accept specific keys: dockle --accept-key DOCKERCONTENTTRUST --format json <image>`
- Parse the results — Read JSON output and present findings:
| # | Level | Code | Title | Finding |
|---|-------|------|-------|---------|- Summarize — Provide total issues by level (FATAL/WARN/INFO/SKIP/PASS).
Key Dockle Checks (CIS Docker Benchmark)
| Code | Description |
|---|---|
| CIS-DI-0001 | Create a user for the container (don't run as root) |
| CIS-DI-0002 | Add HEALTHCHECK instruction |
| CIS-DI-0003 | Do not use update instructions alone |
| CIS-DI-0005 | Do not use COPY with sensitive files (.env, .git, etc.) |
| CIS-DI-0006 | Add LABEL to the image |
| CIS-DI-0008 | Confirm safety of setuid/setgid files |
| CIS-DI-0009 | Use COPY instead of ADD |
| CIS-DI-0010 | Do not store secrets in LABEL or ENV |
| DKL-DI-0001 | Avoid sudo usage |
| DKL-DI-0002 | Avoid sensitive directory mount |
| DKL-DI-0005 | Clear package manager cache |