container-hadolint

name	container-hadolint
description	Dockerfile security linting and best practice validation using Hadolint with 100+ built-in rules aligned to CIS Docker Benchmark. Use when: (1) Analyzing Dockerfiles for security misconfigurations and anti-patterns, (2) Enforcing container image security best practices in CI/CD pipelines, (3) Detecting hardcoded secrets and credentials in container builds, (4) Validating compliance with CIS Docker Benchmark requirements, (5) Integrating shift-left container security into developer workflows, (6) Providing remediation guidance for insecure Dockerfile instructions.
version	0.1.0
maintainer	SirAppSec
category	devsecops
tags	["docker","hadolint","dockerfile","container-security","cis-benchmark","linting","ci-cd"]
frameworks	["CIS","OWASP"]
dependencies	{"tools":["hadolint","docker"]}
references	["https://github.com/hadolint/hadolint","https://www.cisecurity.org/benchmark/docker","https://docs.docker.com/develop/develop-images/dockerfile_best-practices/"]

Dockerfile Security Linting with Hadolint

Overview

Hadolint is a Dockerfile linter that validates container build files against security best practices and the CIS Docker Benchmark. It analyzes Dockerfile instructions to identify misconfigurations, anti-patterns, and security vulnerabilities before images are built and deployed.

Hadolint integrates ShellCheck to validate RUN instructions, ensuring shell commands follow security best practices. With 100+ built-in rules mapped to CIS Docker Benchmark controls, Hadolint provides comprehensive security validation for container images.

Quick Start

Install Hadolint

# macOS via Homebrew
brew install hadolint

# Linux via binary
wget -O /usr/local/bin/hadolint https://github.com/hadolint/hadolint/releases/latest/download/hadolint-Linux-x86_64
chmod +x /usr/local/bin/hadolint

# Via Docker
docker pull hadolint/hadolint

Scan Dockerfile

# Scan Dockerfile in current directory
hadolint Dockerfile

# Scan with specific Dockerfile path
hadolint path/to/Dockerfile

# Using Docker
docker run --rm -i hadolint/hadolint < Dockerfile

Generate Report

# JSON output for automation
hadolint -f json Dockerfile > hadolint-report.json

# GitLab Code Quality format
hadolint -f gitlab_codeclimate Dockerfile > hadolint-codeclimate.json

# Checkstyle format for CI integration
hadolint -f checkstyle Dockerfile > hadolint-checkstyle.xml

Core Workflows

1. Local Development Scanning

Validate Dockerfiles during development:

# Basic scan with colored output
hadolint Dockerfile

# Scan with specific severity threshold
hadolint --failure-threshold error Dockerfile

# Show only warnings and errors
hadolint --no-color --format tty Dockerfile | grep -E "^(warning|error)"

# Verbose output with rule IDs
hadolint -t style -t warning -t error Dockerfile

Output Format:

Dockerfile:3 DL3008 warning: Pin versions in apt get install
Dockerfile:7 DL3025 error: Use JSON notation for CMD and ENTRYPOINT
Dockerfile:12 DL3059 info: Multiple RUN instructions detected