Add Docker setup for frontend, backend & MongoDB

.dockerignore

@@ -0,0 +1,10 @@
+node_modules
+npm-debug.log
+Dockerfile
+.dockerignore
+.git
+.gitignore
+README.md
+client
+server
+docker-compose.yml

client/Dockerfile

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+# Use official Nginx image
+FROM nginx:alpine
+
+# Remove default Nginx website
+RUN rm -rf /usr/share/nginx/html/*
+
+# Copy static files from public directory to Nginx html root
+# Note: This copies the contents of 'public' directly to '/usr/share/nginx/html'
+COPY public/ /usr/share/nginx/html/
+
+# Copy custom Nginx configuration
+COPY client/nginx.conf /etc/nginx/conf.d/default.conf
+
+# Expose port 80
+EXPOSE 80
+
+# Start Nginx
+CMD ["nginx", "-g", "daemon off;"]

client/nginx.conf

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+server {
+    listen 80;
+    server_name localhost;
+
+    root /usr/share/nginx/html;
+    index index.html;
+
+    # Serve static files from root
+    # Serve static files from root
+    location / {
+        try_files $uri $uri/ $uri.html /index.html;
+
+        # Security Headers (Matching Helmet config from server.js)
+        add_header X-Frame-Options "SAMEORIGIN";
+        add_header X-Content-Type-Options "nosniff";
+        add_header Referrer-Policy "strict-origin-when-cross-origin";
+        # CSP is complex to replicate exactly in Nginx without dynamic values, 
+        # but we add a baseline here. The backend API responses will still carry their own CSP.
+        add_header Content-Security-Policy "default-src 'self' https: data: blob: 'unsafe-inline' 'unsafe-eval'; img-src 'self' data: https:; font-src 'self' https: data:;";
+    }
+
+    # Proxy API requests to the backend service
+    location /api/ {
+        proxy_pass http://backend:3000;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection 'upgrade';
+        proxy_set_header Host $host;
+        proxy_cache_bypass $http_upgrade;
+    }
+
+    # Proxy Socket.IO requests
+    location /socket.io/ {
+        proxy_pass http://backend:3000;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
+        proxy_set_header Host $host;
+    }
+}

docker-compose.yml

@@ -1,9 +1,43 @@
-version: "3.9"
+version: '3.8'
 
 services:
-  expenseflow:
-    build: .
-    image: expenseflow:latest
+  # Frontend Application (Nginx)
+  frontend:
+    build:
+      context: .
+      dockerfile: client/Dockerfile
     ports:
-      - "8080:80"
-    restart: unless-stopped
+      - "3000:80"
+    depends_on:
+      - backend
+    restart: always
+
+  # Backend Application (Node.js/Express)
+  backend:
+    build:
+      context: .
+      dockerfile: server/Dockerfile
+    ports:
+      - "3001:3000" # Expose on 3001 to avoid conflict with frontend on host
+    environment:
+      - PORT=3000
+      - MONGODB_URI=mongodb://mongo:27017/expenseflow
+      - NODE_ENV=development
+      - FRONTEND_URL=http://localhost:3000
+    env_file:
+      - .env
+    depends_on:
+      - mongo
+    restart: always
+
+  # Database (MongoDB)
+  mongo:
+    image: mongo:latest
+    ports:
+      - "27017:27017"
+    volumes:
+      - mongo-data:/data/db
+    restart: always
+
+volumes:
+  mongo-data:

server/Dockerfile

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+# Use official Node.js image
+FROM node:18-alpine
+
+# Set working directory
+WORKDIR /app
+
+# Copy package files first for better caching
+COPY package*.json ./
+
+# Install dependencies
+RUN npm install
+
+# Copy the rest of the application code
+COPY . .
+
+# Expose the port the app runs on
+EXPOSE 3000
+
+# Start the application
+CMD ["npm", "run", "dev"]