Fix audit middleware file handle leak on shutdown

pkg/audit/config.go

@@ -5,11 +5,8 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"net/http"
 	"os"
 	"path/filepath"
-
-	"github.com/stacklok/toolhive/pkg/transport/types"
 )
 
 // Config represents the audit logging configuration.
@@ -104,28 +101,6 @@ func (c *Config) ShouldAuditEvent(eventType string) bool {
 	return true
 }
 
-// CreateMiddlewareWithTransport creates an HTTP middleware from the audit configuration with transport information.
-func (c *Config) CreateMiddlewareWithTransport(transportType string) (types.MiddlewareFunction, error) {
-	auditor, err := NewAuditorWithTransport(c, transportType)
-	if err != nil {
-		return nil, fmt.Errorf("failed to create auditor: %w", err)
-	}
-	return auditor.Middleware, nil
-}
-
-// GetMiddlewareFromFile loads the audit configuration from a file and creates an HTTP middleware.
-// Note: This function requires a transport type to be provided separately.
-func GetMiddlewareFromFile(path string, transportType string) (func(http.Handler) http.Handler, error) {
-	// Load the configuration
-	config, err := LoadFromFile(path)
-	if err != nil {
-		return nil, fmt.Errorf("failed to load audit config: %w", err)
-	}
-
-	// Create the middleware with transport information
-	return config.CreateMiddlewareWithTransport(transportType)
-}
-
 // Validate validates the audit configuration.
 func (c *Config) Validate() error {
 	if c.MaxDataSize < 0 {

pkg/audit/config_test.go

@@ -113,15 +113,6 @@ func TestShouldAuditEventExcludeTakesPrecedence(t *testing.T) {
 	assert.False(t, config.ShouldAuditEvent("mcp_resource_read")) // Not in EventTypes
 }
 
-func TestCreateMiddleware(t *testing.T) {
-	t.Parallel()
-	config := &Config{}
-
-	middleware, err := config.CreateMiddlewareWithTransport("sse")
-	assert.NoError(t, err)
-	assert.NotNil(t, middleware)
-}
-
 func TestValidateValidConfig(t *testing.T) {
 	t.Parallel()
 	config := &Config{
@@ -238,14 +229,6 @@ func TestConfigMinimalJSON(t *testing.T) {
 	assert.Equal(t, 0, config.MaxDataSize) // Default zero value
 }
 
-func TestGetMiddlewareFromFileError(t *testing.T) {
-	t.Parallel()
-	// Test with non-existent file
-	_, err := GetMiddlewareFromFile("/non/existent/file.json", "sse")
-	assert.Error(t, err)
-	assert.Contains(t, err.Error(), "failed to load audit config")
-}
-
 func TestLoadFromFilePathCleaning(t *testing.T) {
 	t.Parallel()
 	// Test that filepath.Clean is used (this is more of a smoke test)

pkg/audit/middleware.go

@@ -24,6 +24,7 @@ type MiddlewareParams struct {
 // Middleware wraps audit middleware functionality
 type Middleware struct {
 	middleware types.MiddlewareFunction
+	auditor    *Auditor
 }
 
 // Handler returns the middleware function used by the proxy.
@@ -32,8 +33,10 @@ func (m *Middleware) Handler() types.MiddlewareFunction {
 }
 
 // Close cleans up any resources used by the middleware.
-func (*Middleware) Close() error {
-	// Audit middleware doesn't need cleanup
+func (m *Middleware) Close() error {
+	if m.auditor != nil {
+		return m.auditor.Close()
+	}
 	return nil
 }
 
@@ -67,13 +70,16 @@ func CreateMiddleware(config *types.MiddlewareConfig, runner types.MiddlewareRun
 		auditConfig.Component = params.Component
 	}
 
-	// Always use the transport-aware constructor
-	middleware, err := auditConfig.CreateMiddlewareWithTransport(params.TransportType)
+	// Create the auditor directly so we can store a reference for cleanup
+	auditor, err := NewAuditorWithTransport(auditConfig, params.TransportType)
 	if err != nil {
 		return fmt.Errorf("failed to create audit middleware: %w", err)
 	}
 
-	auditMw := &Middleware{middleware: middleware}
+	auditMw := &Middleware{
+		middleware: auditor.Middleware,
+		auditor:    auditor,
+	}
 	runner.AddMiddleware(config.Type, auditMw)
 	return nil
 }