Container Scanner

Wrapper for Hadolint and Trivy to scan Dockerfiles and container images.

Prerequisites

# Hadolint (Dockerfile linting)
brew install hadolint
# or
docker pull hadolint/hadolint

# Trivy (container image scanning)
brew install trivy
# or
curl -sfL https://raw.githubusercontent.com/aquasecurity/trivy/main/contrib/install.sh | sh -s -- -b /usr/local/bin

Usage

# Lint Dockerfile
npx container-scanner lint Dockerfile

# Scan container image
npx container-scanner image nginx:latest

# Both operations with JSON output
npx container-scanner lint Dockerfile --json
npx container-scanner image myapp:v1 --json

# Check available tools
npx container-scanner --check

Hadolint Rules

Common Dockerfile best practices checked:

Rule	Description
DL3000	Use absolute WORKDIR
DL3001	For some POSIX utilities, you can skip using apt-get
DL3002	Last USER should not be root
DL3003	Use WORKDIR to switch directories
DL3006	Always tag the version of an image explicitly
DL3007	Using latest is prone to errors
DL3008	Pin versions in apt get install
DL3009	Delete apt-get lists after installing
DL3018	Pin versions in apk add
DL4006	Set SHELL option -o pipefail

Output Format

Dockerfile Lint

{
  "tool": "hadolint",
  "scanPath": "Dockerfile",
  "findings": [
    {
      "id": "DL3007",
      "severity": "warning",
      "line": 1,
      "message": "Using latest is prone to errors...",
      "file": "Dockerfile"
    }
  ],
  "summary": { "total": 1, "error": 0, "warning": 1, "info": 0 }
}

Image Scan

{
  "tool": "trivy",
  "image": "nginx:latest",
  "findings": [
    {
      "id": "CVE-2024-1234",
      "severity": "critical",
      "package": "openssl",
      "installedVersion": "1.1.1",
      "fixedVersion": "1.1.2",
      "title": "Buffer Overflow"
    }
  ],
  "summary": { "total": 5, "critical": 1, "high": 2, "medium": 2 }
}

Exit Codes

• 0

  : No issues found

• 1

  : Issues detected

• 2

  : Tool not installed or error