Dockerfile Generator Free Online Tool 2026

Last updated March 22, 2026

Key Best Practices Applied

• Use specific version tags (node:20-alpine, not node:latest) for reproducible builds
• Use slim/alpine base images to minimize image size
• Copy dependency files before source code to maximize layer cache reuse
• Run as a non-root user for security
• Use multi-stage builds to exclude build tools from production images
• Add HEALTHCHECK instructions for container orchestration
• Use .dockerignore to exclude unnecessary files from the build context

Use the Dockerfile Generator at techconverter.me to select your application type and framework, configure your requirements, and get a production-ready Dockerfile with all best practices applied automatically.

# Generated Dockerfile for Node.js (Express API)
# Multi-stage build for smaller production image

# Stage 1: Build
FROM node:20-alpine AS builder
WORKDIR /app

# Copy dependency files first (cache optimization)
COPY package.json package-lock.json ./
RUN npm ci --only=production

# Stage 2: Production
FROM node:20-alpine AS production
WORKDIR /app

# Run as non-root user (security best practice)
RUN addgroup -S appgroup && adduser -S appuser -G appgroup

# Copy only production dependencies
COPY --from=builder /app/node_modules ./node_modules
COPY . .

USER appuser

EXPOSE 3000

HEALTHCHECK --interval=30s --timeout=3s --start-period=5s \
  CMD wget -qO- http://localhost:3000/health || exit 1

CMD ["node", "src/index.js"]

# Generated Dockerfile for Python FastAPI application

FROM python:3.12-slim AS base

# Install system dependencies
RUN apt-get update && apt-get install -y --no-install-recommends \
    curl \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /app

# Copy requirements first (layer cache optimization)
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt

# Copy application code
COPY . .

# Run as non-root user
RUN useradd -m -u 1001 appuser
USER appuser

EXPOSE 8000

HEALTHCHECK --interval=30s --timeout=10s --start-period=5s \
  CMD curl -f http://localhost:8000/health || exit 1

CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]

# Generated Dockerfile for Java Spring Boot
# Uses JDK for build, JRE for runtime (smaller image)

# Stage 1: Build with Maven
FROM maven:3.9-eclipse-temurin-21 AS builder
WORKDIR /app

# Copy pom.xml first for dependency caching
COPY pom.xml .
RUN mvn dependency:go-offline -q

# Copy source and build
COPY src ./src
RUN mvn package -DskipTests -q

# Stage 2: Runtime with JRE only
FROM eclipse-temurin:21-jre-alpine AS production
WORKDIR /app

# Non-root user
RUN addgroup -S spring && adduser -S spring -G spring

COPY --from=builder /app/target/*.jar app.jar

USER spring

EXPOSE 8080

HEALTHCHECK --interval=30s --timeout=10s --start-period=60s \
  CMD wget -qO- http://localhost:8080/actuator/health || exit 1

ENTRYPOINT ["java", "-jar", "app.jar"]