ROX-31475: add stdio support

Signed-off-by: Tomasz Janiszewski <tomek@redhat.com>

# Conflicts:
#	internal/server/server.go

Author: janisz

internal/config/config.go

@@ -29,6 +29,7 @@ type Config struct {
 }
 
 type authType string
+type serverType string
 
 const (
 	// AuthTypePassthrough defines auth flow where API token, used to communicate with MCP server,
@@ -38,6 +39,9 @@ const (
 	// AuthTypeStatic defines auth flow where API token is statically configured and
 	// defined in configuration or environment variable.
 	AuthTypeStatic authType = "static"
+
+	ServerTypeStdio          serverType = "stdio"
+	ServerTypeStreamableHttp serverType = "streamable-http"
 )
 
 // CentralConfig contains StackRox Central connection configuration.
@@ -62,8 +66,9 @@ type GlobalConfig struct {
 
 // ServerConfig contains HTTP server configuration.
 type ServerConfig struct {
-	Address string `mapstructure:"address"`
-	Port    int    `mapstructure:"port"`
+	Type    serverType `mapstructure:"type"`
+	Address string     `mapstructure:"address"`
+	Port    int        `mapstructure:"port"`
 }
 
 // ToolsConfig contains configuration for individual MCP tools.
@@ -138,6 +143,7 @@ func setDefaults(viper *viper.Viper) {
 
 	viper.SetDefault("server.address", "0.0.0.0")
 	viper.SetDefault("server.port", defaultPort)
+	viper.SetDefault("server.type", ServerTypeStreamableHttp)
 
 	viper.SetDefault("tools.vulnerability.enabled", false)
 	viper.SetDefault("tools.config_manager.enabled", false)
@@ -207,6 +213,12 @@ func (cc *CentralConfig) validate() error {
 }
 
 func (sc *ServerConfig) validate() error {
+	if sc.Type != ServerTypeStreamableHttp && sc.Type != ServerTypeStdio {
+		return errors.New("server.type must be either streamable-http or stdio")
+	}
+	if sc.Type == ServerTypeStdio {
+		return nil
+	}
 	if sc.Address == "" {
 		return errors.New("server.address is required")
 	}

internal/config/config_test.go

@@ -201,6 +201,24 @@ tools:
 	assert.Contains(t, err.Error(), "central.url is required")
 }
 
+func TestLoadConfig_ValidationPass(t *testing.T) {
+	validYAMLInvalidConfig := `
+central:
+  url: "localhost:8080"
+server:
+  type: stdio
+  address: ""
+  port: 0
+tools:
+  vulnerability:
+    enabled: true
+`
+
+	configPath := testutil.WriteYAMLFile(t, validYAMLInvalidConfig)
+	_, err := LoadConfig(configPath)
+	require.NoError(t, err)
+}
+
 func TestValidate_MissingURL(t *testing.T) {
 	cfg := getDefaultConfig()
 	cfg.Central.URL = ""

internal/logging/logging.go

@@ -31,7 +31,7 @@ func SetupLogging() {
 	}
 
 	// Initialize slog with JSON handler.
-	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
+	logger := slog.New(slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{
 		Level: logLevel,
 	}))
 

internal/server/server.go

@@ -53,6 +53,10 @@ func NewServer(cfg *config.Config, registry *toolsets.Registry) *Server {
 func (s *Server) Start(ctx context.Context) error {
 	s.registerTools()
 
+	if s.cfg.Server.Type == "stdio" {
+		return s.mcp.Run(ctx, &mcp.StdioTransport{})
+	}
+
 	// Create a new ServeMux for routing.
 	mux := http.NewServeMux()
 	s.registerRouteHealth(mux)