Caddy + Next.js + Docker build

.env

DOMAIN=http//:localhost

# For production, use a real domain without scheme (http:// or https://) to be served with auto-renewal HTTPS/SSL
#  DOMAIN=example.com

app.dockerfile

FROM node:21.7.1-alpine3.19 AS base

FROM base AS deps
RUN apk add --no-cache libc6-compat

WORKDIR /app

COPY package.json package-lock.json ./
RUN npm ci

FROM base AS builder

WORKDIR /app
COPY --from=deps /app/node_modules ./node_modules

COPY public ./public
COPY src ./src
COPY next.config.mjs ./next.config.mjs
COPY package.json ./package.json
COPY package-lock.json ./package-lock.json
COPY postcss.config.js ./postcss.config.js
COPY tailwind.config.ts ./tailwind.config.ts
COPY tsconfig.json ./tsconfig.json
# You can simply replace all above COPY commands with below command for your own project
#  COPY . .

ENV NEXT_TELEMETRY_DISABLED 1

RUN npm run build

FROM base AS runner

WORKDIR /app

ENV NODE_ENV production
ENV NEXT_TELEMETRY_DISABLED 1

RUN addgroup --system --gid 1001 nodejs
RUN adduser --system --uid 1001 nextjs

COPY --from=builder /app/public ./public
COPY package.json ./package.json

RUN mkdir -p /app/.next
RUN chown nextjs:nodejs /app/.next

COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static

USER nextjs

EXPOSE 3000
ENV PORT 3000

CMD HOSTNAME="0.0.0.0" node server.js

caddy.dockerfile

FROM caddy/caddy:2.7.6-alpine

COPY Caddyfile /etc/caddy/Caddyfile

CMD ["caddy", "run", "--config", "/etc/caddy/Caddyfile", "--adapter", "caddyfile"]

Caddyfile

{$DOMAIN} {
  handle {
    reverse_proxy landing:3000
  }
}

compose.yml

services:
  app:
    restart: always
    container_name: landing_app
    hostname: landing  # underscore make it invalid (RFC 1034/1035)
    build:
      context: ./
      dockerfile: app.dockerfile
    env_file:
      - .env
    expose:
      - 3000
    logging:
      driver: "json-file"
      options:
        max-size: "100m"
        max-file: "5"

  caddy:
    container_name: caddy
    hostname: caddy
    restart: unless-stopped
    build:
      context: ./
      dockerfile: caddy.dockerfile
    depends_on:
      - "app"
    volumes:
      - ./data/caddy_data:/data
      - ./data/caddy_config:/config
    env_file:
      - .env
    ports:
      - "80:80"
      - "443:443"
    logging:
      driver: "json-file"
      options:
        max-size: "100m"
        max-file: "5"

next.config.mjs

/** @type {import('next').NextConfig} */
const nextConfig = {
  reactStrictMode: false,
  output: "standalone",
};


export default nextConfig;