refactor(streamable): /mcp and /health endpoints (#32)

move the MCP endpoint to `/mcp` and add an `/health` endpoint for health checks

Signed-off-by: Xavier Coulon <xcoulon@redhat.com>

Author: xcoulon

cmd/start_server.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"log/slog"
 	"net/http"
@@ -74,12 +75,23 @@ var startServerCmd = &cobra.Command{
 				return fmt.Errorf("failed to serve on stdio: %v", err.Error())
 			}
 		default:
-			handler := mcp.NewStreamableHTTPHandler(func(*http.Request) *mcp.Server {
+			mux := http.NewServeMux()
+			// MCP endpoint
+			mux.Handle("/mcp", mcp.NewStreamableHTTPHandler(func(*http.Request) *mcp.Server {
 				return srv
-			}, nil)
+			}, nil))
+			// HealthCheck endpoint.
+			mux.HandleFunc("/health", func(w http.ResponseWriter, _ *http.Request) {
+				w.Header().Set("Content-Type", "application/json")
+				json.NewEncoder(w).Encode(map[string]string{ //nolint:errcheck
+					"status": "healthy",
+					"time":   time.Now().Format(time.RFC3339),
+				})
+			})
+
 			server := &http.Server{
 				Addr:         listen,
-				Handler:      handler,
+				Handler:      mux,
 				ReadTimeout:  15 * time.Second,
 				WriteTimeout: 15 * time.Second,
 				IdleTimeout:  60 * time.Second,

test/e2e/server_test.go

@@ -245,7 +245,7 @@ func newHTTPSession(mcpServerListen string, mcpServerDebug bool, argocdURL strin
 		cl := mcp.NewClient(&mcp.Implementation{Name: "e2e-test-client", Version: "v1.0.0"}, nil)
 		session, err := cl.Connect(ctx, &mcp.StreamableClientTransport{
 			MaxRetries: 5,
-			Endpoint:   fmt.Sprintf("http://%s", os.Getenv("MCP_SERVER_LISTEN")),
+			Endpoint:   fmt.Sprintf("http://%s/mcp", os.Getenv("MCP_SERVER_LISTEN")),
 		}, nil)
 		require.NoError(t, err)
 		return session, func() {