Dockerfile

# Multi-stage Docker build for SDC Web React application.
# Stage 1: Build Caddy with transform-encoder module.
# Stage 2: Build the React application.
# Stage 3: Serve with Caddy web server.

# Build arguments for version control.
ARG NODE_VERSION=20
ARG CADDY_VERSION=2-alpine

# --------------------------------------------------------------------------------
# Stage 1: Caddy Builder - Build Caddy with transform-encoder module.
# This module is required for transforming logs to a more readable format.
# To optimise logs for machine parsing, just use the normal caddy image
# with the json logger.
FROM caddy:builder AS caddy-builder

RUN xcaddy build \
    --with github.com/caddyserver/transform-encoder

# -------------------------------------------------------------------------------- 
# Stage 2: React Builder - Build the React app.
FROM node:${NODE_VERSION}-alpine AS builder

WORKDIR /app

# Copy package files for dependency installation.
COPY package*.json ./

# Install dependencies. Use clean install for reproducible builds.
RUN npm ci

# Copy source code.
COPY . .

# Build the application.
RUN npm run build

# --------------------------------------------------------------------------------
# Stage 3: Production - Serve with Caddy.
FROM caddy:${CADDY_VERSION}

# Copy custom-built Caddy binary with transform-encoder module.
COPY --from=caddy-builder /usr/bin/caddy /usr/bin/caddy

# Copy built static files from builder stage.
COPY --from=builder /app/dist /usr/share/caddy

# Copy Caddyfile for server configuration.
COPY configs/Caddyfile /etc/caddy/Caddyfile

# Extract version from package.json for labeling.
COPY --from=builder /app/package.json /tmp/package.json

# Add labels for container metadata.
LABEL org.opencontainers.image.title="SDC Web"
LABEL org.opencontainers.image.description="Supermarket Data Collector Web Application"
LABEL org.opencontainers.image.source="https://github.com/dfmoller/sdc-web"

# Expose HTTP and HTTPS ports.
EXPOSE 80
EXPOSE 443

# Health check endpoint.
HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
  CMD wget --no-verbose --tries=1 --spider http://localhost:80/ || exit 1

# Caddy runs as non-root by default and serves from /usr/share/caddy.
# No CMD needed, the base caddy image handles it.