hooks: do not error when hook handler is not registered (2.27) (#3819)

hooks: do not error when hook handler is not registered (2.27)

2 files changed, 28 insertions, 0 deletions

diff --git a/overlord/hookstate/hookmgr.go b/overlord/hookstate/hookmgr.go
index 2e764d6631..ecd5ff133a 100644
--- a/overlord/hookstate/hookmgr.go
+++ b/overlord/hookstate/hookmgr.go
@@ -227,6 +227,9 @@ func (m *HookManager) doRunHook(task *state.Task, tomb *tomb.Tomb) error {
	handlers := m.repository.generateHandlers(context)
	handlersCount := len(handlers)
	if handlersCount == 0 {
+	if hooksup.Optional {
+	return nil
+	}
	return fmt.Errorf("internal error: no registered handlers for hook %q", hooksup.Hook)
	}
	if handlersCount > 1 {
diff --git a/overlord/hookstate/hookstate_test.go b/overlord/hookstate/hookstate_test.go
index 569fcbb5fa..919e7b549f 100644
--- a/overlord/hookstate/hookstate_test.go
+++ b/overlord/hookstate/hookstate_test.go
@@ -594,6 +594,31 @@ func (s *hookManagerSuite) TestHookWithoutHookOptional(c *C) {
	c.Logf("Task log:\n%s\n", s.task.Log())
 }
 
+func (s *hookManagerSuite) TestOptionalHookWithMissingHandler(c *C) {
+	hooksup := &hookstate.HookSetup{
+	Snap: "test-snap",
+	Hook: "missing-hook-and-no-handler",
+	Optional: true,
+	}
+	s.state.Lock()
+	s.task.Set("hook-setup", hooksup)
+	s.state.Unlock()
+
+	s.manager.Ensure()
+	s.manager.Wait()
+
+	c.Check(s.command.Calls(), IsNil)
+
+	s.state.Lock()
+	defer s.state.Unlock()
+
+	c.Check(s.task.Kind(), Equals, "run-hook")
+	c.Check(s.task.Status(), Equals, state.DoneStatus)
+	c.Check(s.change.Status(), Equals, state.DoneStatus)
+
+	c.Logf("Task log:\n%s\n", s.task.Log())
+}
+
 func checkTaskLogContains(c *C, task *state.Task, pattern string) {
	exp := regexp.MustCompile(pattern)
	found := false