NextJs Docker file for small builds

Dockerfile

# Stage 1: Build the application
FROM node:18-alpine AS builder

# Set working directory
WORKDIR /app

# A wildcard is used to ensure both package.json AND package-lock.json are copied
COPY package*.json ./

# Install all app dependencies
RUN npm i --legacy-peer-deps
# RUN npm i

# Bundle app source
COPY . .

# Set build argument for environment
ARG APP_ENV
ENV APP_ENV $APP_ENV

# Copy the corresponding .env file based on the build environment
COPY .env.$APP_ENV .env

# Build the application
RUN npm run build:special

# Stage 2: Run the application with a minimal image
FROM node:18-alpine AS runner

# Set working directory
WORKDIR /app

# Set build argument for port
ARG PORT
ENV PORT $PORT

# Copy the built application from the builder stage
COPY --from=builder /app/.next ./.next
COPY --from=builder /app/public ./public
COPY --from=builder /app/package.json ./package.json
COPY --from=builder /app/package-lock.json ./package-lock.json
COPY --from=builder /app/next.config.js ./next.config.js
COPY --from=builder /app/.env ./.env

# Install only production dependencies
RUN npm i  --only=production --legacy-peer-deps

# Expose the port Next.js runs on
EXPOSE $PORT

# Start the application
CMD ["npm", "start"]
#--build-arg APP_ENV=development
#--build-arg APP_ENV=production