Dockerfile

# --------------------
# Stage 1: Build Stage
# --------------------
# Use slim version of Node.js 22 for smaller image size
FROM node:22-slim AS build

# Set working directory inside the container
WORKDIR /app

# Copy only package.json and package-lock.json
# (This allows Docker to cache npm install step if dependencies don't change)
COPY package*.json ./

# Install production dependencies only
# - `npm ci` (ci - Clean Install) ensures clean and fast installation
# - `--omit=dev` skips dev dependencies (like testing, linting tools)
RUN npm install

# Now copy the rest of your application code
COPY . .

# ----------------------------
# Stage 2: Production Stage (Distroless)
# ----------------------------
# Use very small distroless image that has only Node.js runtime
FROM gcr.io/distroless/nodejs22-debian12

# Set working directory
WORKDIR /app

# Copy built app + node_modules from build stage
COPY --from=build /app /app

# Expose the port your server listens on
EXPOSE 8085

# Start the server
# (Distroless will automatically use "index.js" if present, but CMD is better for clarity)
CMD ["index.js"]