fix(test): move SIGHUP tests to separate file for Windows compatibility

Use build tag instead of runtime skip to exclude Unix-specific
SIGHUP signal tests from Windows builds.

Signed-off-by: Marc Nuri <[email protected]>

Author: manusa

pkg/kubernetes-mcp-server/cmd/root_sighup_test.go

@@ -0,0 +1,209 @@
+//go:build !windows
+
+package cmd
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"slices"
+	"strings"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/containers/kubernetes-mcp-server/internal/test"
+	"github.com/containers/kubernetes-mcp-server/pkg/config"
+	"github.com/containers/kubernetes-mcp-server/pkg/mcp"
+	"github.com/stretchr/testify/suite"
+	"k8s.io/klog/v2"
+	"k8s.io/klog/v2/textlogger"
+)
+
+// SIGHUPSuite tests the SIGHUP configuration reload behavior
+type SIGHUPSuite struct {
+	suite.Suite
+	mockServer      *test.MockServer
+	server          *mcp.Server
+	tempDir         string
+	dropInConfigDir string
+	logBuffer       *bytes.Buffer
+}
+
+func (s *SIGHUPSuite) SetupTest() {
+	s.mockServer = test.NewMockServer()
+	s.mockServer.Handle(&test.DiscoveryClientHandler{})
+	s.tempDir = s.T().TempDir()
+	s.dropInConfigDir = filepath.Join(s.tempDir, "conf.d")
+	s.Require().NoError(os.Mkdir(s.dropInConfigDir, 0755))
+
+	// Set up klog to write to our buffer so we can verify log messages
+	s.logBuffer = &bytes.Buffer{}
+	logger := textlogger.NewLogger(textlogger.NewConfig(textlogger.Verbosity(2), textlogger.Output(s.logBuffer)))
+	klog.SetLoggerWithOptions(logger)
+}
+
+func (s *SIGHUPSuite) TearDownTest() {
+	if s.server != nil {
+		s.server.Close()
+	}
+	if s.mockServer != nil {
+		s.mockServer.Close()
+	}
+}
+
+func (s *SIGHUPSuite) InitServer(configPath, configDir string) {
+	cfg, err := config.Read(configPath, configDir)
+	s.Require().NoError(err)
+	cfg.KubeConfig = s.mockServer.KubeconfigFile(s.T())
+
+	s.server, err = mcp.NewServer(mcp.Configuration{
+		StaticConfig: cfg,
+	})
+	s.Require().NoError(err)
+	// Set up SIGHUP handler
+	opts := &MCPServerOptions{
+		ConfigPath: configPath,
+		ConfigDir:  configDir,
+	}
+	opts.setupSIGHUPHandler(s.server)
+}
+
+func (s *SIGHUPSuite) TestSIGHUPReloadsConfigFromFile() {
+	// Create initial config file - start with only core toolset (no helm)
+	configPath := filepath.Join(s.tempDir, "config.toml")
+	s.Require().NoError(os.WriteFile(configPath, []byte(`
+		toolsets = ["core", "config"]
+	`), 0644))
+	s.InitServer(configPath, "")
+
+	s.Run("helm tools are not initially available", func() {
+		s.False(slices.Contains(s.server.GetEnabledTools(), "helm_list"))
+	})
+
+	// Modify the config file to add helm toolset
+	s.Require().NoError(os.WriteFile(configPath, []byte(`
+		toolsets = ["core", "config", "helm"]
+	`), 0644))
+
+	// Send SIGHUP to current process
+	s.Require().NoError(syscall.Kill(syscall.Getpid(), syscall.SIGHUP))
+
+	s.Run("helm tools become available after SIGHUP", func() {
+		s.Require().Eventually(func() bool {
+			return slices.Contains(s.server.GetEnabledTools(), "helm_list")
+		}, 2*time.Second, 50*time.Millisecond)
+	})
+}
+
+func (s *SIGHUPSuite) TestSIGHUPReloadsFromDropInDirectory() {
+	// Create initial config file - with helm enabled
+	configPath := filepath.Join(s.tempDir, "config.toml")
+	s.Require().NoError(os.WriteFile(configPath, []byte(`
+		toolsets = ["core", "config", "helm"]
+	`), 0644))
+
+	// Create initial drop-in file that removes helm
+	dropInPath := filepath.Join(s.dropInConfigDir, "10-override.toml")
+	s.Require().NoError(os.WriteFile(dropInPath, []byte(`
+		toolsets = ["core", "config"]
+	`), 0644))
+
+	s.InitServer(configPath, "")
+
+	s.Run("drop-in override removes helm from initial config", func() {
+		s.False(slices.Contains(s.server.GetEnabledTools(), "helm_list"))
+	})
+
+	// Update drop-in file to add helm back
+	s.Require().NoError(os.WriteFile(dropInPath, []byte(`
+		toolsets = ["core", "config", "helm"]
+	`), 0644))
+
+	// Send SIGHUP
+	s.Require().NoError(syscall.Kill(syscall.Getpid(), syscall.SIGHUP))
+
+	s.Run("helm tools become available after updating drop-in and sending SIGHUP", func() {
+		s.Require().Eventually(func() bool {
+			return slices.Contains(s.server.GetEnabledTools(), "helm_list")
+		}, 2*time.Second, 50*time.Millisecond)
+	})
+}
+
+func (s *SIGHUPSuite) TestSIGHUPWithInvalidConfigContinues() {
+	// Create initial config file - start with only core toolset (no helm)
+	configPath := filepath.Join(s.tempDir, "config.toml")
+	s.Require().NoError(os.WriteFile(configPath, []byte(`
+		toolsets = ["core", "config"]
+	`), 0644))
+	s.InitServer(configPath, "")
+
+	s.Run("helm tools are not initially available", func() {
+		s.False(slices.Contains(s.server.GetEnabledTools(), "helm_list"))
+	})
+
+	// Write invalid TOML to config file
+	s.Require().NoError(os.WriteFile(configPath, []byte(`
+		toolsets = "not a valid array
+	`), 0644))
+
+	// Send SIGHUP - should not panic, should continue with old config
+	s.Require().NoError(syscall.Kill(syscall.Getpid(), syscall.SIGHUP))
+
+	s.Run("logs error when config is invalid", func() {
+		s.Require().Eventually(func() bool {
+			return strings.Contains(s.logBuffer.String(), "Failed to reload configuration")
+		}, 2*time.Second, 50*time.Millisecond)
+	})
+
+	s.Run("tools remain unchanged after failed reload", func() {
+		s.True(slices.Contains(s.server.GetEnabledTools(), "events_list"))
+		s.False(slices.Contains(s.server.GetEnabledTools(), "helm_list"))
+	})
+
+	// Now fix the config and add helm
+	s.Require().NoError(os.WriteFile(configPath, []byte(`
+		toolsets = ["core", "config", "helm"]
+	`), 0644))
+
+	// Send another SIGHUP
+	s.Require().NoError(syscall.Kill(syscall.Getpid(), syscall.SIGHUP))
+
+	s.Run("helm tools become available after fixing config and sending SIGHUP", func() {
+		s.Require().Eventually(func() bool {
+			return slices.Contains(s.server.GetEnabledTools(), "helm_list")
+		}, 2*time.Second, 50*time.Millisecond)
+	})
+}
+
+func (s *SIGHUPSuite) TestSIGHUPWithConfigDirOnly() {
+	// Create initial drop-in file without helm
+	dropInPath := filepath.Join(s.dropInConfigDir, "10-settings.toml")
+	s.Require().NoError(os.WriteFile(dropInPath, []byte(`
+		toolsets = ["core", "config"]
+	`), 0644))
+
+	s.InitServer("", s.dropInConfigDir)
+
+	s.Run("helm tools are not initially available", func() {
+		s.False(slices.Contains(s.server.GetEnabledTools(), "helm_list"))
+	})
+
+	// Update drop-in file to add helm
+	s.Require().NoError(os.WriteFile(dropInPath, []byte(`
+		toolsets = ["core", "config", "helm"]
+	`), 0644))
+
+	// Send SIGHUP
+	s.Require().NoError(syscall.Kill(syscall.Getpid(), syscall.SIGHUP))
+
+	s.Run("helm tools become available after SIGHUP with config-dir only", func() {
+		s.Require().Eventually(func() bool {
+			return slices.Contains(s.server.GetEnabledTools(), "helm_list")
+		}, 2*time.Second, 50*time.Millisecond)
+	})
+}
+
+func TestSIGHUP(t *testing.T) {
+	suite.Run(t, new(SIGHUPSuite))
+}