prevent panic when orbit is run with updates disabled (#12654)

for #11980

orbit/changes/11980-updates-panic

@@ -0,0 +1 @@
+* Fixed a crash that happened when updates where disabled and certain conditions (Nudge configuration set or host elegible for MDM migration) were met.

orbit/pkg/update/nudge.go

@@ -71,6 +71,11 @@ func (n *NudgeConfigFetcher) GetConfig() (*fleet.OrbitConfig, error) {
 		return nil, nil
 	}
 
+	if n.opt.UpdateRunner == nil {
+		log.Debug().Msg("NudgeConfigFetcher received nil UpdateRunner, this probably indicates that updates are turned off. Skipping any actions related to Nudge")
+		return cfg, nil
+	}
+
 	if cfg.NudgeConfig == nil {
 		log.Debug().Msg("empty nudge config, removing nudge as target")
 		// TODO(roberto): by early returning and removing the target from the

orbit/pkg/update/nudge_test.go

@@ -25,6 +25,29 @@ type nudgeTestSuite struct {
 	withTUF
 }
 
+func (s *nudgeTestSuite) TestUpdatesDisabled() {
+	t := s.T()
+	var err error
+	cfg := &fleet.OrbitConfig{}
+	cfg.NudgeConfig, err = fleet.NewNudgeConfig(fleet.MacOSUpdates{MinimumVersion: optjson.SetString("11"), Deadline: optjson.SetString("2022-01-04")})
+	require.NoError(t, err)
+	runNudgeFn := func(execPath, configPath string) error {
+		return nil
+	}
+	var f OrbitConfigFetcher = &dummyConfigFetcher{cfg: cfg}
+	f = ApplyNudgeConfigFetcherMiddleware(f, NudgeConfigFetcherOptions{
+		UpdateRunner: nil,
+		RootDir:      t.TempDir(),
+		Interval:     time.Minute,
+		runNudgeFn:   runNudgeFn,
+	})
+
+	// we used to get a panic if updates were disabled (see #11980)
+	gotCfg, err := f.GetConfig()
+	require.NoError(t, err)
+	require.Equal(t, cfg, gotCfg)
+}
+
 func (s *nudgeTestSuite) TestNudgeConfigFetcherAddNudge() {
 	t := s.T()
 	tmpDir := t.TempDir()
@@ -69,6 +92,8 @@ func (s *nudgeTestSuite) TestNudgeConfigFetcherAddNudge() {
 	// add nuge to the remote
 	s.addRemoteTarget(nudgePath)
 
+	// nothing happens if a nil runner is provided
+
 	// nudge is added to targets when nudge config is present
 	gotCfg, err = f.GetConfig()
 	require.NoError(t, err)

orbit/pkg/update/swift_dialog.go

@@ -35,6 +35,11 @@ func (s *SwiftDialogDownloader) GetConfig() (*fleet.OrbitConfig, error) {
 		return nil, nil
 	}
 
+	if s.UpdateRunner == nil {
+		log.Debug().Msg("SwiftDialogDownloader received nil UpdateRunner, this probably indicates that updates are turned off. Skipping any actions related to swiftDialog")
+		return cfg, nil
+	}
+
 	if !cfg.Notifications.NeedsMDMMigration && !cfg.Notifications.RenewEnrollmentProfile {
 		return cfg, nil
 	}

orbit/pkg/update/swift_dialog_test.go

@@ -0,0 +1,21 @@
+package update
+
+import (
+	"testing"
+
+	"github.com/fleetdm/fleet/v4/server/fleet"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSwiftDialogUpdatesDisabled(t *testing.T) {
+	cfg := &fleet.OrbitConfig{}
+	cfg.Notifications.NeedsMDMMigration = true
+	cfg.Notifications.RenewEnrollmentProfile = true
+	var f OrbitConfigFetcher = &dummyConfigFetcher{cfg: cfg}
+	f = ApplySwiftDialogDownloaderMiddleware(f, nil)
+
+	// we used to get a panic if updates were disabled (see #11980)
+	gotCfg, err := f.GetConfig()
+	require.NoError(t, err)
+	require.Equal(t, cfg, gotCfg)
+}