feat: add NetBox MCP server for infrastructure management

Comprehensive MCP server covering the entire NetBox REST API:
- DCIM: sites, racks, devices, interfaces, cables, power
- IPAM: prefixes, IP addresses, VLANs, VRFs, ASNs
- Circuits: providers, circuits, terminations
- Virtualization: clusters, VMs, VM interfaces
- Tenancy: tenants, contacts, contact assignments
- VPN: tunnels, IKE/IPSec policies, L2VPN
- Wireless: WLANs, links, groups
- Extras: tags, custom fields, webhooks, audit log

Features:
- 100+ MCP tools for full CRUD operations
- Auto-pagination handling
- Hybrid config (system + project level)
- Available prefix/IP allocation support

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

mcp-servers/netbox/mcp_server/config.py

@@ -0,0 +1,108 @@
+"""
+Configuration loader for NetBox MCP Server.
+
+Implements hybrid configuration system:
+- System-level: ~/.config/claude/netbox.env (credentials)
+- Project-level: .env (optional overrides)
+"""
+from pathlib import Path
+from dotenv import load_dotenv
+import os
+import logging
+from typing import Dict, Optional
+
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+
+class NetBoxConfig:
+    """Configuration loader for NetBox MCP Server"""
+
+    def __init__(self):
+        self.api_url: Optional[str] = None
+        self.api_token: Optional[str] = None
+        self.verify_ssl: bool = True
+        self.timeout: int = 30
+
+    def load(self) -> Dict[str, any]:
+        """
+        Load configuration from system and project levels.
+        Project-level configuration overrides system-level.
+
+        Returns:
+            Dict containing api_url, api_token, verify_ssl, timeout
+
+        Raises:
+            FileNotFoundError: If system config is missing
+            ValueError: If required configuration is missing
+        """
+        # Load system config
+        system_config = Path.home() / '.config' / 'claude' / 'netbox.env'
+        if system_config.exists():
+            load_dotenv(system_config)
+            logger.info(f"Loaded system configuration from {system_config}")
+        else:
+            raise FileNotFoundError(
+                f"System config not found: {system_config}\n"
+                "Create it with:\n"
+                "  mkdir -p ~/.config/claude\n"
+                "  cat > ~/.config/claude/netbox.env << EOF\n"
+                "  NETBOX_API_URL=https://your-netbox-instance/api\n"
+                "  NETBOX_API_TOKEN=your-api-token\n"
+                "  EOF"
+            )
+
+        # Load project config (overrides system)
+        project_config = Path.cwd() / '.env'
+        if project_config.exists():
+            load_dotenv(project_config, override=True)
+            logger.info(f"Loaded project configuration from {project_config}")
+
+        # Extract values
+        self.api_url = os.getenv('NETBOX_API_URL')
+        self.api_token = os.getenv('NETBOX_API_TOKEN')
+
+        # Optional settings with defaults
+        verify_ssl_str = os.getenv('NETBOX_VERIFY_SSL', 'true').lower()
+        self.verify_ssl = verify_ssl_str in ('true', '1', 'yes')
+
+        timeout_str = os.getenv('NETBOX_TIMEOUT', '30')
+        try:
+            self.timeout = int(timeout_str)
+        except ValueError:
+            self.timeout = 30
+            logger.warning(f"Invalid NETBOX_TIMEOUT value '{timeout_str}', using default 30")
+
+        # Validate required variables
+        self._validate()
+
+        # Normalize API URL (remove trailing slash)
+        if self.api_url and self.api_url.endswith('/'):
+            self.api_url = self.api_url.rstrip('/')
+
+        return {
+            'api_url': self.api_url,
+            'api_token': self.api_token,
+            'verify_ssl': self.verify_ssl,
+            'timeout': self.timeout
+        }
+
+    def _validate(self) -> None:
+        """
+        Validate that required configuration is present.
+
+        Raises:
+            ValueError: If required configuration is missing
+        """
+        required = {
+            'NETBOX_API_URL': self.api_url,
+            'NETBOX_API_TOKEN': self.api_token
+        }
+
+        missing = [key for key, value in required.items() if not value]
+
+        if missing:
+            raise ValueError(
+                f"Missing required configuration: {', '.join(missing)}\n"
+                "Check your ~/.config/claude/netbox.env file"
+            )