
Docker Security
- 31 installs
- 2 repo stars
- Updated January 5, 2026
- pluginagentmarketplace/custom-plugin-docker
Run structured Docker and container security checks with configurable strictness before you ship images or merge infra changes.
About
docker-security is a marketplace plugin skill aimed at solo builders and small teams who containerize services and want agent-guided security validation instead of ad-hoc Dockerfile reviews. The packaged configuration defines how validation runs: whether strict mode is on, whether the agent may auto-fix findings, and how results are formatted for downstream review. Development defaults keep logging verbose and rules relaxed so you can iterate; production profile tightens strict_mode and reduces log noise to warnings. Integrations with git, linters, and formatters position the skill inside your normal ship pipeline rather than as a one-off chat prompt. Use it when you are preparing images for registry push, tightening compose files, or aligning container settings with a repeatable security checklist the agent can apply consistently across repos.
- JSON Schema–backed skill config with semver versioning and security category enum
- Validation block with strict_mode and auto_fix toggles for dev vs production
- Markdown output format with optional examples for agent-readable reports
- Integration hooks for git, linter, and formatter workflows
- Environment overrides separating debug logging in development from warn-level production checks
Docker Security by the numbers
- 31 all-time installs (skills.sh)
- +1 installs in the week ending Jul 26, 2026 (Skillselion tracking)
- Ranked #1,482 of 2,209 Security skills by installs in the Skillselion catalog
- Security screen: HIGH risk (skills.sh audit)
- Data as of Jul 26, 2026 (Skillselion catalog sync)
npx skills add https://github.com/pluginagentmarketplace/custom-plugin-docker --skill docker-securityAdd your badge
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| Installs | 31 |
|---|---|
| repo stars | ★ 2 |
| Security audit | 2 / 3 scanners passed |
| Last updated | January 5, 2026 |
| Repository | pluginagentmarketplace/custom-plugin-docker ↗ |
What it does
Run structured Docker and container security checks with configurable strictness before you ship images or merge infra changes.
Files
Docker Security Skill
Master container security hardening, vulnerability scanning, and secrets management following CIS Docker Benchmark.
Purpose
Implement security best practices for Docker containers and images including non-root users, capability dropping, and vulnerability scanning.
Parameters
| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
| image | string | No | - | Image to scan |
| severity | enum | No | HIGH | CRITICAL/HIGH/MEDIUM/LOW |
| compliance | string | No | CIS | CIS/NIST/SOC2 |
Security Hardening
Non-Root User (MANDATORY)
# Create non-root user
RUN addgroup -g 1001 app && \
adduser -u 1001 -G app -D app
# Set ownership
COPY --chown=app:app . /app
# Switch user
USER appRead-Only Filesystem
docker run --read-only \
--tmpfs /tmp:rw,noexec,nosuid \
myapp:latestDrop Capabilities
docker run \
--cap-drop ALL \
--cap-add NET_BIND_SERVICE \
myapp:latestComplete Hardened Run
docker run \
--security-opt no-new-privileges:true \
--cap-drop ALL \
--read-only \
--user 1001:1001 \
--pids-limit 100 \
--memory 512m \
myapp:latestVulnerability Scanning
Trivy
# Basic scan
trivy image myapp:latest
# Filter by severity
trivy image --severity CRITICAL,HIGH myapp:latest
# CI/CD integration (fail on critical)
trivy image --exit-code 1 --severity CRITICAL myapp:latest
# JSON output
trivy image --format json --output report.json myapp:latestDocker Scout
# Quick scan
docker scout cves myapp:latest
# Detailed report
docker scout cves --format markdown myapp:latestSecrets Management
Docker Compose Secrets
services:
database:
image: postgres:16-alpine
secrets:
- db_password
environment:
POSTGRES_PASSWORD_FILE: /run/secrets/db_password
secrets:
db_password:
file: ./secrets/db_password.txtBuildKit Secrets
# syntax=docker/dockerfile:1
RUN --mount=type=secret,id=npmrc,target=/root/.npmrc \
npm installdocker build --secret id=npmrc,src=.npmrc .Secure Dockerfile
FROM node:20-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production
COPY . .
RUN npm run build
FROM gcr.io/distroless/nodejs20-debian12
WORKDIR /app
COPY --from=builder /app/dist ./dist
COPY --from=builder /app/node_modules ./node_modules
USER nonroot
CMD ["dist/index.js"]Error Handling
Common Errors
| Error | Cause | Solution |
|---|---|---|
permission denied | Non-root user | Fix file ownership |
read-only filesystem | Read-only mode | Use tmpfs mounts |
operation not permitted | Missing capability | Add specific cap |
Fallback Strategy
1. Start without restrictions 2. Add security options incrementally 3. Test each restriction
Troubleshooting
Debug Checklist
- [ ] Running as non-root?
docker exec <c> id - [ ] Scanned for vulnerabilities?
- [ ] Capabilities dropped?
- [ ] Secrets not in env vars?
CIS Benchmark
docker run --rm --net host --pid host \
-v /var/run/docker.sock:/var/run/docker.sock \
docker/docker-bench-securityUsage
Skill("docker-security")Related Skills
- dockerfile-basics
- docker-production
# docker-security Configuration
# Category: security
# Generated: 2025-12-30
skill:
name: docker-security
version: "1.0.0"
category: security
settings:
# Default settings for docker-security
enabled: true
log_level: info
# Category-specific defaults
validation:
strict_mode: false
auto_fix: false
output:
format: markdown
include_examples: true
# Environment-specific overrides
environments:
development:
log_level: debug
validation:
strict_mode: false
production:
log_level: warn
validation:
strict_mode: true
# Integration settings
integrations:
# Enable/disable integrations
git: true
linter: true
formatter: true
{
"$schema": "http://json-schema.org/draft-07/schema#",
"title": "docker-security Configuration Schema",
"type": "object",
"properties": {
"skill": {
"type": "object",
"properties": {
"name": {
"type": "string"
},
"version": {
"type": "string",
"pattern": "^\\d+\\.\\d+\\.\\d+$"
},
"category": {
"type": "string",
"enum": [
"api",
"testing",
"devops",
"security",
"database",
"frontend",
"algorithms",
"machine-learning",
"cloud",
"containers",
"general"
]
}
},
"required": [
"name",
"version"
]
},
"settings": {
"type": "object",
"properties": {
"enabled": {
"type": "boolean",
"default": true
},
"log_level": {
"type": "string",
"enum": [
"debug",
"info",
"warn",
"error"
]
}
}
}
},
"required": [
"skill"
]
}# Docker Security Checklist
image_security:
- Use official base images
- Scan images with Trivy/Snyk
- Pin image versions (no :latest)
- Use multi-stage builds
- Remove unnecessary packages
runtime_security:
- Run as non-root user
- Use read-only filesystem
- Drop unnecessary capabilities
- Use security profiles (seccomp, AppArmor)
- Limit resources (memory, CPU)
network_security:
- Use internal networks
- Don't expose unnecessary ports
- Use TLS for communication
- Implement network policies
secrets_management:
- Use Docker secrets
- Never hardcode passwords
- Use environment variables carefully
- Rotate secrets regularly
Docker Security Guide
Overview
This guide provides comprehensive documentation for the docker-security skill in the custom-plugin-docker plugin.
Category: Security
Quick Start
Prerequisites
- Familiarity with security concepts
- Development environment set up
- Plugin installed and configured
Basic Usage
# Invoke the skill
claude "docker-security - [your task description]"
# Example
claude "docker-security - analyze the current implementation"Core Concepts
Key Principles
1. Consistency - Follow established patterns 2. Clarity - Write readable, maintainable code 3. Quality - Validate before deployment
Best Practices
- Always validate input data
- Handle edge cases explicitly
- Document your decisions
- Write tests for critical paths
Common Tasks
Task 1: Basic Implementation
# Example implementation pattern
def implement_docker_security(input_data):
"""
Implement docker-security functionality.
Args:
input_data: Input to process
Returns:
Processed result
"""
# Validate input
if not input_data:
raise ValueError("Input required")
# Process
result = process(input_data)
# Return
return resultTask 2: Advanced Usage
For advanced scenarios, consider:
- Configuration customization via
assets/config.yaml - Validation using
scripts/validate.py - Integration with other skills
Troubleshooting
Common Issues
| Issue | Cause | Solution |
|---|---|---|
| Skill not found | Not installed | Run plugin sync |
| Validation fails | Invalid config | Check config.yaml |
| Unexpected output | Missing context | Provide more details |
Related Resources
- SKILL.md - Skill specification
- config.yaml - Configuration options
- validate.py - Validation script
---
Last updated: 2025-12-30
Docker Security Patterns
Design Patterns
Pattern 1: Input Validation
Always validate input before processing:
def validate_input(data):
if data is None:
raise ValueError("Data cannot be None")
if not isinstance(data, dict):
raise TypeError("Data must be a dictionary")
return TruePattern 2: Error Handling
Use consistent error handling:
try:
result = risky_operation()
except SpecificError as e:
logger.error(f"Operation failed: {e}")
handle_error(e)
except Exception as e:
logger.exception("Unexpected error")
raisePattern 3: Configuration Loading
Load and validate configuration:
import yaml
def load_config(config_path):
with open(config_path) as f:
config = yaml.safe_load(f)
validate_config(config)
return configAnti-Patterns to Avoid
❌ Don't: Swallow Exceptions
# BAD
try:
do_something()
except:
pass✅ Do: Handle Explicitly
# GOOD
try:
do_something()
except SpecificError as e:
logger.warning(f"Expected error: {e}")
return default_valueCategory-Specific Patterns: Security
Recommended Approach
1. Start with the simplest implementation 2. Add complexity only when needed 3. Test each addition 4. Document decisions
Common Integration Points
- Configuration:
assets/config.yaml - Validation:
scripts/validate.py - Documentation:
references/GUIDE.md
---
Pattern library for docker-security skill
#!/usr/bin/env python3
"""
Validation script for docker-security skill.
Category: security
"""
import os
import sys
import yaml
import json
from pathlib import Path
def validate_config(config_path: str) -> dict:
"""
Validate skill configuration file.
Args:
config_path: Path to config.yaml
Returns:
dict: Validation result with 'valid' and 'errors' keys
"""
errors = []
if not os.path.exists(config_path):
return {"valid": False, "errors": ["Config file not found"]}
try:
with open(config_path, 'r') as f:
config = yaml.safe_load(f)
except yaml.YAMLError as e:
return {"valid": False, "errors": [f"YAML parse error: {e}"]}
# Validate required fields
if 'skill' not in config:
errors.append("Missing 'skill' section")
else:
if 'name' not in config['skill']:
errors.append("Missing skill.name")
if 'version' not in config['skill']:
errors.append("Missing skill.version")
# Validate settings
if 'settings' in config:
settings = config['settings']
if 'log_level' in settings:
valid_levels = ['debug', 'info', 'warn', 'error']
if settings['log_level'] not in valid_levels:
errors.append(f"Invalid log_level: {settings['log_level']}")
return {
"valid": len(errors) == 0,
"errors": errors,
"config": config if not errors else None
}
def validate_skill_structure(skill_path: str) -> dict:
"""
Validate skill directory structure.
Args:
skill_path: Path to skill directory
Returns:
dict: Structure validation result
"""
required_dirs = ['assets', 'scripts', 'references']
required_files = ['SKILL.md']
errors = []
# Check required files
for file in required_files:
if not os.path.exists(os.path.join(skill_path, file)):
errors.append(f"Missing required file: {file}")
# Check required directories
for dir in required_dirs:
dir_path = os.path.join(skill_path, dir)
if not os.path.isdir(dir_path):
errors.append(f"Missing required directory: {dir}/")
else:
# Check for real content (not just .gitkeep)
files = [f for f in os.listdir(dir_path) if f != '.gitkeep']
if not files:
errors.append(f"Directory {dir}/ has no real content")
return {
"valid": len(errors) == 0,
"errors": errors,
"skill_name": os.path.basename(skill_path)
}
def main():
"""Main validation entry point."""
skill_path = Path(__file__).parent.parent
print(f"Validating docker-security skill...")
print(f"Path: {skill_path}")
# Validate structure
structure_result = validate_skill_structure(str(skill_path))
print(f"\nStructure validation: {'PASS' if structure_result['valid'] else 'FAIL'}")
if structure_result['errors']:
for error in structure_result['errors']:
print(f" - {error}")
# Validate config
config_path = skill_path / 'assets' / 'config.yaml'
if config_path.exists():
config_result = validate_config(str(config_path))
print(f"\nConfig validation: {'PASS' if config_result['valid'] else 'FAIL'}")
if config_result['errors']:
for error in config_result['errors']:
print(f" - {error}")
else:
print("\nConfig validation: SKIPPED (no config.yaml)")
# Summary
all_valid = structure_result['valid']
print(f"\n==================================================")
print(f"Overall: {'VALID' if all_valid else 'INVALID'}")
return 0 if all_valid else 1
if __name__ == "__main__":
sys.exit(main())
Related skills
FAQ
Is Docker Security safe to install?
skills.sh reports 2 of 3 security scanners passed. Review the Security Audits panel on this page before installing in production.