Dockerfile

# Build stage
FROM node:18-alpine AS build

# Set working directory
WORKDIR /app

# Copy package files
COPY package*.json ./

# Install dependencies
RUN npm ci

# Copy source code
COPY . .

# In Docker, frontend calls paths like "api/heatmapdata/process/"
# Setting BASE_API_PATH to "/" makes full URL "/api/heatmapdata/process/"
# which nginx proxies to the backend container
ENV REACT_APP_API_URL=/
RUN npm run build

# Production stage
FROM nginx:alpine

# Copy built assets from build stage
COPY --from=build /app/build /usr/share/nginx/html

# Copy nginx configuration if needed
RUN cat > /etc/nginx/conf.d/default.conf << 'EOF'
server {
    listen 80;
    server_name localhost;

    location / {
        root /usr/share/nginx/html;
        index index.html index.htm;
        try_files $uri $uri/ /index.html;
    }

    # API proxy to backend container
    location /api/ {
        proxy_pass http://backend:8000/api/;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        client_max_body_size 1G;
        proxy_read_timeout 300s;
        proxy_connect_timeout 300s;
    }

    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/html;
    }
}
EOF

# Expose port
EXPOSE 80

# Start nginx
CMD ["nginx", "-g", "daemon off;"]