🌐 Nornir MCP Server

A FastMCP server providing network automation tools powered by Nornir and NAPALM.

This server acts as a bridge, exposing Nornir/NAPALM network operations as MCP (Massively Concurrent Processing) tools, making them easily accessible from compatible MCP clients (like the FastMCP Web UI).

✨ Key Features

• Leverages Nornir for inventory management and concurrent task execution against network devices.
• Uses NAPALM for multi-vendor device interaction (information gathering, command execution).
• Built with FastMCP for seamless integration with MCP clients using various transports (SSE in this configuration).
• Containerized with Docker 🐳 for easy setup and deployment.
• Uses uv for fast Python dependency management within the container ⚡.

🔧 Prerequisites

Before you begin, ensure you have the following installed:

• Docker
• Docker Compose (Usually included with Docker Desktop)

⚙️ Configuration

Before running the server, you must configure your network inventory and device credentials:

1. Navigate to the conf/ directory in the project.
2. Edit hosts.yaml: Define your network devices. Specify their management IP/hostname, platform (e.g., ios, junos, eos), credentials (if not using defaults), and assign them to groups if desired.
3. Edit groups.yaml: Define device groups with shared properties (like platform or connection options). Settings here can override defaults.
4. Edit defaults.yaml: Set default credentials (username, password) and connection options (like NAPALM secret for enable passwords or default platform).
   • ⚠️ Important Security Note: The default configuration uses plaintext credentials in YAML files. This is suitable for testing/lab environments. For production, strongly consider using Nornir's built-in secrets management features (e.g., environment variables, HashiCorp Vault plugin) to avoid storing sensitive information directly in configuration files. Modify nornir_ops.py and your configuration if you implement a secrets provider.
5. Review config.yaml: Ensure the inventory file paths (host_file, group_file, defaults_file) point correctly to the files within the conf/ directory (they should by default). Adjust runner options (num_workers) if needed.

▶️ Running the Server

Once configured, you can easily run the server using Docker Compose:

1. Ensure you have configured the conf/ directory as described above.
2. Open a terminal or command prompt in the project's root directory (the same directory as the Dockerfile and docker-compose.yml files).
3. Run the following command:

   docker-compose up --build -d

   • The --build flag tells Docker Compose to build the image based on the Dockerfile the first time or if any project files (like .py files or pyproject.toml) have changed.
   • This command will start the Nornir MCP server in a Docker container.
4. The server logs will be displayed in your terminal. By default, it should be accessible on port 8000 of your host machine (localhost).
5. To stop the server, press Ctrl+C in the terminal where docker-compose is running. To remove the container afterwards, run docker-compose down.

🔌 Adding to MCP Client

To use the tools provided by this server in an MCP client (like the official FastMCP Web UI or other compatible clients):

1. Make sure the Nornir MCP server is running (using docker-compose up).
2. Open your MCP client application.
3. Find the option to add or manage MCP Server connections.
4. Add a new connection with the following details:
   • Server URL: Since this server uses the SSE (Server-Sent Events) transport and runs on port 8000 by default, the URL will be:
     • http://localhost:8000/sse
     • (If your Docker host has a different IP address accessible by the client, replace localhost with that IP, e.g., http://192.168.1.100:8000/sse)
   • Connection Name: Give it a descriptive name, for example, Nornir Lab Server.
5. Save and connect to the newly added server.
6. The MCP client should discover the Nornir_MCP service and list all the available tools (like get_facts, send_command, etc.). You can now use these tools via the client interface! 🎉

Dify DSL Examples

1. Nornir MCP.yml - A simple example to chat with your devices.
2. Device Check.yml - An example to run Device Assessment Report.

🛠️ Available Tools & Resources

Once connected via an MCP client, the following tools (under the "Nornir_MCP" service name) should typically be available:

• Inventory:
  • list_all_hosts: Lists devices configured in your Nornir inventory (conf/hosts.yaml).
• NAPALM Getters: (Retrieve information)
  • get_facts
  • get_interfaces
  • get_interfaces_ip
  • get_interfaces_counters
  • get_config (with retrieve option: running, startup, candidate)
  • get_arp_table
  • get_mac_address_table
  • get_users
  • get_vlans
  • get_snmp_information
  • get_bgp_neighbors
  • (Availability depends on device platform and NAPALM driver support)
• Execution:
  • send_command: Send a single, read-only command to a device and get the output.
• Streaming Resource:
  • sse://updates: Provides a simple heartbeat event stream. (Can be subscribed to by clients supporting SSE resources).

📄 License

This project is licensed under the MIT License.

🙌 Contributing

Contributions, issues, and feature requests are welcome! Please feel free to submit them via the project's repository.

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