curl --request POST \
  --url https://api.iotools.cloud/v1/tool/dockerfile-linter \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "dockerfile": "FROM ubuntu:latest\n\nMAINTAINER john@example.com\n\nRUN apt-get update\nRUN apt-get install -y curl wget git\nRUN cd /app && npm install\n\nADD ./config.txt /app/config.txt\n\nENV DB_PASSWORD=mysecretpass123\nENV API_KEY=sk-1234567890abcdef\n\nEXPOSE 8080\nEXPOSE 99999\n\nCOPY . /app\n\nRUN chmod +x /app/start.sh\n\nCMD node server.js"
}
'

{
  "tool": "dockerfile-linter",
  "tool_version": "1.0.1",
  "outputs": {
    "summary": [
      {
        "severity": "Errors",
        "count": "1"
      },
      {
        "severity": "Warnings",
        "count": "9"
      },
      {
        "severity": "Info",
        "count": "3"
      },
      {
        "severity": "Total",
        "count": "13"
      }
    ],
    "issues": [
      {
        "line": "1",
        "severity": "Warning",
        "rule": "DL3007",
        "message": "Using the :latest tag is not recommended",
        "explanation": "Pin to a specific version for reproducible builds (e.g., node:18-alpine instead of node:latest)."
      },
      {
        "line": "3",
        "severity": "Warning",
        "rule": "DL4000",
        "message": "MAINTAINER is deprecated — use LABEL maintainer=\"...\"",
        "explanation": "The MAINTAINER instruction is deprecated. Use LABEL maintainer=\"name\" instead."
      },
      {
        "line": "5",
        "severity": "Warning",
        "rule": "DL3059",
        "message": "3 consecutive RUN instructions — consider combining",
        "explanation": "Each RUN creates a new layer. Combine with && \\ to reduce layers and image size."
      },
      {
        "line": "6",
        "severity": "Warning",
        "rule": "DL3009",
        "message": "Delete the apt-get lists after installing packages",
        "explanation": "Run \"rm -rf /var/lib/apt/lists/*\" after apt-get install to reduce image size."
      },
      {
        "line": "6",
        "severity": "Info",
        "rule": "DL3015",
        "message": "Use --no-install-recommends with apt-get install",
        "explanation": "Avoids installing unnecessary recommended packages, reducing image size."
      },
      {
        "line": "7",
        "severity": "Warning",
        "rule": "DL3003",
        "message": "Use WORKDIR to switch directories instead of cd in RUN",
        "explanation": "Using cd in RUN does not persist across instructions. Use WORKDIR instead."
      },
      {
        "line": "9",
        "severity": "Warning",
        "rule": "DL3020",
        "message": "Use COPY instead of ADD for files and folders",
        "explanation": "ADD has extra features (auto-extraction, URLs) that make it less predictable. Use COPY unless you need ADD features."
      },
      {
        "line": "11",
        "severity": "Warning",
        "rule": "DL3060",
        "message": "Possible secret or credential in ENV",
        "explanation": "Avoid hardcoding secrets in Dockerfiles. Use --build-arg, Docker secrets, or runtime environment variables."
      },
      {
        "line": "12",
        "severity": "Warning",
        "rule": "DL3060",
        "message": "Possible secret or credential in ENV",
        "explanation": "Avoid hardcoding secrets in Dockerfiles. Use --build-arg, Docker secrets, or runtime environment variables."
      },
      {
        "line": "15",
        "severity": "Error",
        "rule": "DL3011",
        "message": "Invalid EXPOSE port: 99999",
        "explanation": "Port numbers must be between 0 and 65535."
      },
      {
        "line": "21",
        "severity": "Warning",
        "rule": "DL3002",
        "message": "No USER instruction found — container will run as root",
        "explanation": "Running containers as root is a security risk. Add a USER instruction to run as a non-root user."
      },
      {
        "line": "21",
        "severity": "Info",
        "rule": "DL3025",
        "message": "Use JSON notation for CMD",
        "explanation": "Use CMD [\"executable\", \"param1\"] to avoid shell processing issues."
      },
      {
        "line": "21",
        "severity": "Info",
        "rule": "DL3048",
        "message": "Missing HEALTHCHECK instruction",
        "explanation": "Add a HEALTHCHECK to let Docker know how to check if the container is still working."
      }
    ],
    "formatted": "FROM ubuntu:latest\n\nMAINTAINER john@example.com\n\nRUN apt-get update && \\\n    apt-get install -y curl git wget && \\\n    cd /app && \\\n    npm install\n\nADD ./config.txt /app/config.txt\n\nENV DB_PASSWORD=mysecretpass123\nENV API_KEY=sk-1234567890abcdef\n\nEXPOSE 8080\nEXPOSE 99999\n\nCOPY . /app\n\nRUN chmod +x /app/start.sh\n\nCMD node server.js\n"
  },
  "credits_used": 3,
  "credits_remaining": null
}