terminate plugin clients explicitly instead of using managed ones

Signed-off-by: Steve Kriss <steve@heptio.com>

pkg/plugin/client_store.go

@@ -71,6 +71,22 @@ func (s *clientStore) list(kind PluginKind, scope string) ([]*plugin.Client, err
 	return nil, errors.New("clients not found")
 }
 
+// listAll returns all plugin clients for all kinds/scopes, or a
+// zero-valued slice if there are none.
+func (s *clientStore) listAll() []*plugin.Client {
+	s.lock.RLock()
+	defer s.lock.RUnlock()
+
+	var clients []*plugin.Client
+	for _, pluginsByName := range s.clients {
+		for name := range pluginsByName {
+			clients = append(clients, pluginsByName[name])
+		}
+	}
+
+	return clients
+}
+
 // add stores a plugin client for the given kind/name/scope.
 func (s *clientStore) add(client *plugin.Client, kind PluginKind, name, scope string) {
 	s.lock.Lock()
@@ -103,3 +119,11 @@ func (s *clientStore) deleteAll(kind PluginKind, scope string) {
 
 	delete(s.clients, clientKey{kind, scope})
 }
+
+// clear removes all clients for all kinds/scopes from the store.
+func (s *clientStore) clear() {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	s.clients = make(map[clientKey]map[string]*plugin.Client)
+}

pkg/plugin/manager.go

@@ -44,7 +44,6 @@ func baseConfig() *plugin.ClientConfig {
 	return &plugin.ClientConfig{
 		HandshakeConfig:  Handshake,
 		AllowedProtocols: []plugin.Protocol{plugin.ProtocolGRPC},
-		Managed:          true,
 	}
 }
 
@@ -112,7 +111,7 @@ type Manager interface {
 
 	// CloseBackupItemActions terminates the plugin sub-processes that
 	// are hosting BackupItemAction plugins for the given backup name.
-	CloseBackupItemActions(backupName string) error
+	CloseBackupItemActions(backupName string)
 
 	// GetRestoreItemActions returns all restore.ItemAction plugins.
 	// These plugin instances should ONLY be used for a single restore
@@ -123,10 +122,10 @@ type Manager interface {
 
 	// CloseRestoreItemActions terminates the plugin sub-processes that
 	// are hosting RestoreItemAction plugins for the given restore name.
-	CloseRestoreItemActions(restoreName string) error
+	CloseRestoreItemActions(restoreName string)
 
-	// CleanupClients kills all plugin subprocesses.
-	CleanupClients()
+	// CloseAllClients terminates all plugin subprocesses.
+	CloseAllClients()
 }
 
 type manager struct {
@@ -349,8 +348,8 @@ func (m *manager) GetBackupItemActions(backupName string) ([]backup.ItemAction,
 
 // CloseBackupItemActions terminates the plugin sub-processes that
 // are hosting BackupItemAction plugins for the given backup name.
-func (m *manager) CloseBackupItemActions(backupName string) error {
-	return closeAll(m.clientStore, PluginKindBackupItemAction, backupName)
+func (m *manager) CloseBackupItemActions(backupName string) {
+	closeAll(m.clientStore, PluginKindBackupItemAction, backupName)
 }
 
 func (m *manager) GetRestoreItemActions(restoreName string) ([]restore.ItemAction, error) {
@@ -398,14 +397,18 @@ func (m *manager) GetRestoreItemActions(restoreName string) ([]restore.ItemActio
 
 // CloseRestoreItemActions terminates the plugin sub-processes that
 // are hosting RestoreItemAction plugins for the given restore name.
-func (m *manager) CloseRestoreItemActions(restoreName string) error {
-	return closeAll(m.clientStore, PluginKindRestoreItemAction, restoreName)
+func (m *manager) CloseRestoreItemActions(restoreName string) {
+	closeAll(m.clientStore, PluginKindRestoreItemAction, restoreName)
 }
 
-func closeAll(store *clientStore, kind PluginKind, scope string) error {
+func closeAll(store *clientStore, kind PluginKind, scope string) {
 	clients, err := store.list(kind, scope)
 	if err != nil {
-		return err
+		// store.list(...) only returns an error if no clients are
+		// found for the specified kind and scope. We don't need
+		// to treat this as an error when trying to close all clients,
+		// because this means there are no clients to close.
+		return
 	}
 
 	for _, client := range clients {
@@ -413,10 +416,12 @@ func closeAll(store *clientStore, kind PluginKind, scope string) error {
 	}
 
 	store.deleteAll(kind, scope)
-
-	return nil
 }
 
-func (m *manager) CleanupClients() {
-	plugin.CleanupClients()
+func (m *manager) CloseAllClients() {
+	for _, client := range m.clientStore.listAll() {
+		client.Kill()
+	}
+
+	m.clientStore.clear()
 }