Add docker-compose support with environment variable configuration

- Create docker-compose.yml with server and agent services
- Add environment variable support to Dockerfiles via entrypoint scripts
- Configure server with ADDR, PORT, USERNAME, PASSWORD vars
- Configure agent with SERVER, INTERVAL, AGENT_ID vars
- Add health check to server service for container orchestration
- Add service dependencies to ensure server starts before agent
- Create .dockerignore to optimize Docker builds
- Update QUICKSTART.md with Docker Compose instructions
- Support running server only, agent only, or full stack
- Support multiple agents with custom identifiers

docker-compose.yml

@@ -0,0 +1,107 @@
+version: '3.8'
+
+# ============================================================================
+# Nerd Monitor Docker Compose Configuration
+# ============================================================================
+# 
+# This file provides multiple ways to run Nerd Monitor:
+#
+# 1. Full Stack (Server + Agent):
+#    docker-compose up
+#
+# 2. Server Only:
+#    docker-compose up server
+#
+# 3. Agent Only (requires external server):
+#    docker-compose up agent
+#    (Set SERVER env var: SERVER=your-server:8080 docker-compose up agent)
+#
+# 4. Multiple Agents:
+#    docker-compose up -d server
+#    docker-compose run --name agent1 -e AGENT_ID=machine1 agent
+#    docker-compose run --name agent2 -e AGENT_ID=machine2 agent
+#
+# ============================================================================
+
+services:
+  # =========================================================================
+  # Nerd Monitor Server
+  # =========================================================================
+  # Web UI and API endpoint for collecting agent statistics
+  #
+  # Environment Variables:
+  #   ADDR: Server bind address (default: 0.0.0.0)
+  #   PORT: Server port (default: 8080)
+  #   USERNAME: Admin username (default: admin)
+  #   PASSWORD: Admin password (default: admin) - CHANGE IN PRODUCTION
+  #
+  server:
+    build:
+      context: .
+      dockerfile: Dockerfile.server
+    container_name: nerd-monitor-server
+    image: nerd-monitor-server:latest
+    ports:
+      - "8080:8080"
+    environment:
+      # Server configuration
+      ADDR: "0.0.0.0"
+      PORT: "8080"
+      # IMPORTANT: Change these credentials in production!
+      USERNAME: "admin"
+      PASSWORD: "admin"
+    healthcheck:
+      test: ["CMD", "wget", "--quiet", "--tries=1", "--spider", "http://localhost:8080/login"]
+      interval: 30s
+      timeout: 3s
+      retries: 3
+      start_period: 5s
+    restart: unless-stopped
+    networks:
+      - nerd-monitor
+    # Resource limits (optional, uncomment to enable)
+    # deploy:
+    #   resources:
+    #     limits:
+    #       cpus: '0.5'
+    #       memory: 512M
+
+  # =========================================================================
+  # Nerd Monitor Agent
+  # =========================================================================
+  # Lightweight monitoring agent that reports system stats to the server
+  #
+  # Environment Variables:
+  #   SERVER: Server address (default: server:8080 when using docker-compose)
+  #   INTERVAL: Reporting interval (default: 15s)
+  #   AGENT_ID: Optional agent identifier (auto-generated from hostname if empty)
+  #
+  # Note: This agent depends on the server being healthy before starting
+  #
+  agent:
+    build:
+      context: .
+      dockerfile: Dockerfile.agent
+    image: nerd-monitor-agent:latest
+    environment:
+      # Agent configuration
+      SERVER: "server:8080"        # Connect to the server service
+      INTERVAL: "15s"              # Report stats every 15 seconds
+      # AGENT_ID: "my-machine"     # Optional: set a custom agent ID
+    depends_on:
+      server:
+        condition: service_healthy  # Wait for server to be healthy
+    restart: unless-stopped
+    networks:
+      - nerd-monitor
+    # Resource limits (optional, uncomment to enable)
+    # deploy:
+    #   resources:
+    #     limits:
+    #       cpus: '0.25'
+    #       memory: 128M
+
+networks:
+  # Shared network for server and agent communication
+  nerd-monitor:
+    driver: bridge