Sample Dockerfile Template

This is a template for creating Docker images. Copy this file and customize it for your application.

Node.js Application Template

# Use official Node.js runtime as base image
FROM node:18-alpine

# Set working directory in container
WORKDIR /app

# Copy package files first for better caching
COPY package*.json ./

# Install dependencies
RUN npm ci --only=production

# Copy application code
COPY . .

# Create non-root user for security
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nextjs -u 1001

# Change ownership of app directory
RUN chown -R nextjs:nodejs /app
USER nextjs

# Expose the port your app runs on
EXPOSE 3000

# Define health check
HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
  CMD curl -f http://localhost:3000/health || exit 1

# Start the application
CMD ["npm", "start"]

Python Application Template

# Use official Python runtime as base image
FROM python:3.11-slim

# Set environment variables
ENV PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1 \
    PIP_NO_CACHE_DIR=1

# Set working directory
WORKDIR /app

# Install system dependencies if needed
RUN apt-get update && apt-get install -y \
    gcc \
    && rm -rf /var/lib/apt/lists/*

# Copy requirements first for better caching
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt

# Copy application code
COPY . .

# Create non-root user
RUN useradd --create-home --shell /bin/bash app \
    && chown -R app:app /app
USER app

# Expose port
EXPOSE 8000

# Run application
CMD ["python", "app.py"]

Go Application Template

# Build stage
FROM golang:1.21-alpine AS builder

WORKDIR /app

# Copy go mod files
COPY go.mod go.sum ./
RUN go mod download

# Copy source code
COPY . .

# Build the application
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o main .

# Final stage
FROM alpine:latest

# Install ca-certificates for HTTPS requests
RUN apk --no-cache add ca-certificates

WORKDIR /root/

# Copy the binary from builder stage
COPY --from=builder /app/main .

# Expose port
EXPOSE 8080

# Run the binary
CMD ["./main"]

Multi-stage Build Template

# Build stage
FROM node:18-alpine AS builder

WORKDIR /app

# Copy package files
COPY package*.json ./
RUN npm ci

# Copy source
COPY . .

# Build application
RUN npm run build

# Production stage
FROM nginx:alpine

# Copy built assets from builder stage
COPY --from=builder /app/dist /usr/share/nginx/html

# Copy nginx configuration
COPY nginx.conf /etc/nginx/nginx.conf

# Expose port
EXPOSE 80

# Start nginx
CMD ["nginx", "-g", "daemon off;"]