// Copyright 2025 The Inspektor Gadget authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package server
import (
"context"
"fmt"
"log/slog"
"net"
"os"
"github.com/mark3labs/mcp-go/server"
"github.com/inspektor-gadget/ig-mcp-server/pkg/tools"
)
const (
StdioTransport = "stdio"
SSETransport = "sse"
StreamableHTTPTransport = "streamable-http"
)
var log = slog.Default().With("component", "sever")
var SupportedTransports = []string{StdioTransport, SSETransport, StreamableHTTPTransport}
// Server is the main server for the Inspektor Gadget MCP server.
type Server struct {
mcpServer *server.MCPServer
sseSever *server.SSEServer
httpServer *server.StreamableHTTPServer
stdioCancel func()
}
// New creates a new instance of the Inspektor Gadget MCP server.
func New(version string, registry *tools.GadgetToolRegistry) *Server {
ms := server.NewMCPServer(
"ig-mcp-server",
version,
server.WithLogging(),
server.WithRecovery(),
)
// Register callback to register tools
registry.RegisterCallback(func(tools ...server.ServerTool) {
ms.SetTools(tools...)
})
return &Server{
mcpServer: ms,
}
}
// Start starts the MCP server and listens for incoming connections based on transport.
func (s *Server) Start(transport, host, port string) error {
switch transport {
case StdioTransport:
log.Info("Starting MCP server", "transport", transport)
var ctx context.Context
ctx, s.stdioCancel = context.WithCancel(context.Background())
return server.NewStdioServer(s.mcpServer).Listen(ctx, os.Stdin, os.Stdout)
case SSETransport:
log.Info("Starting MCP server", "transport", transport, "host", host, "port", port)
s.sseSever = server.NewSSEServer(s.mcpServer)
return s.sseSever.Start(net.JoinHostPort(host, port))
case StreamableHTTPTransport:
log.Info("Starting MCP server", "transport", transport, "host", host, "port", port)
s.httpServer = server.NewStreamableHTTPServer(s.mcpServer)
return s.httpServer.Start(net.JoinHostPort(host, port))
}
return fmt.Errorf("unsupported transport: %s", transport)
}
func (s *Server) Shutdown(ctx context.Context) error {
log.Info("Shutting down MCP server")
if s.stdioCancel != nil {
s.stdioCancel()
}
if s.sseSever != nil {
if err := s.sseSever.Shutdown(ctx); err != nil {
return fmt.Errorf("shutting down SSE server: %w", err)
}
}
if s.httpServer != nil {
if err := s.httpServer.Shutdown(ctx); err != nil {
return fmt.Errorf("shutting down HTTP server: %w", err)
}
}
return nil
}