dockerfile

# Use an official Node runtime as a parent image
FROM node:18-alpine

# Create app directory
WORKDIR /usr/src/app

# Install app dependencies
# We copy package.json and package-lock.json first to leverage Docker cache
COPY package*.json ./

# Install dependencies (use npm ci when package-lock.json is present for reproducible builds)
RUN if [ -f package-lock.json ]; then npm ci --only=production; else npm install --only=production; fi

# Bundle app source
COPY . .

# Expose the port the app runs on
EXPOSE 3000

# Default command
CMD ["node", "nodeserver.js"]

# Build command (run from the directory containing this Dockerfile):
# PowerShell example:
#   docker build -t mynodeapp -f .\dockerfile .
# Run example (maps container port 3000 to host port 3000):
#   docker run --rm -p 3000:3000 mynodeapp