refactor(shutdown): shutdown is now non-blocking

Author: samber

docs/docs/service-lifecycle/shutdowner.md

@@ -18,12 +18,12 @@ A shutdown can be triggered on a root scope:
 
 ```go
 // on demand
-injector.Shutdown() error
-injector.ShutdownWithContext(context.Context) error
+injector.Shutdown() map[string]error
+injector.ShutdownWithContext(context.Context) map[string]error
 
 // on signal
-injector.ShutdownOnSignals(...os.Signal) (os.Signal, error)
-injector.ShutdownOnSignalsWithContext(context.Context, ...os.Signal) (os.Signal, error)
+injector.ShutdownOnSignals(...os.Signal) (os.Signal, map[string]error)
+injector.ShutdownOnSignalsWithContext(context.Context, ...os.Signal) (os.Signal, map[string]error)
 ```
 
 ...on a single service:
@@ -86,5 +86,10 @@ Provide(i, ...)
 Invoke(i, ...)
 
 ctx := context.WithTimeout(10 * time.Second)
-i.ShutdownWithContext(ctx)
+errors := i.ShutdownWithContext(ctx)
+for _, err := range errors {
+    if err != nil {
+		log.Println("shutdown error:", err)
+	}
+}
 ```

docs/docs/upgrading/from-v1-x-to-v2.md

@@ -44,9 +44,9 @@ go mod tidy
 find . -name '*.go' -type f -exec sed -i '' "s/*do.Injector/do.Injector/g" {} \;
 ```
 
-## 3- `do.Shutdown****` output
+## 3- Shutdown
 
-`ShutdownOnSignals` used to return only 1 argument.
+`do.ShutdownOnSignals` used to return only 1 argument.
 
 ```go
 # from
@@ -58,6 +58,8 @@ signal, err := injector.ShutdownOnSignals(syscall.SIGTERM, os.Interrupt)
 
 `injector.ShutdownOnSIGTERM()` has been removed. Use `injector.ShutdownOnSignals(syscall.SIGTERM)` instead.
 
+`injector.Shutdown()` now returns a map of errors (`map[string]error`) and is non-blocking in case of failure of a single service.
+
 ## 4- Internal service naming
 
 Internally, the DI container stores a service by its name (string) that represents its type. In `do@v1`, some developers reported collisions in service names, because the package name was not included.

examples/shutdownable/example.go

@@ -95,7 +95,9 @@ func main() {
 	car.Start()
 
 	_, err := injector.ShutdownOnSignals()
-	if err != nil {
-		log.Fatal(err.Error())
+	for _, e := range err {
+		if e != nil {
+			log.Fatal(e.Error())
+		}
 	}
 }

injector.go

@@ -17,8 +17,8 @@ type Injector interface {
 	ListInvokedServices() []EdgeService
 	HealthCheck() map[string]error
 	HealthCheckWithContext(context.Context) map[string]error
-	Shutdown() error
-	ShutdownWithContext(context.Context) error
+	Shutdown() map[string]error
+	ShutdownWithContext(context.Context) map[string]error
 	clone(*RootScope, *Scope) *Scope
 
 	// service lifecycle

root_scope.go

@@ -66,8 +66,8 @@ func (s *RootScope) HealthCheck() map[string]error          { return s.self.Heal
 func (s *RootScope) HealthCheckWithContext(ctx context.Context) map[string]error {
 	return s.self.HealthCheckWithContext(ctx)
 }
-func (s *RootScope) Shutdown() error { return s.ShutdownWithContext(context.Background()) }
-func (s *RootScope) ShutdownWithContext(ctx context.Context) error {
+func (s *RootScope) Shutdown() map[string]error { return s.ShutdownWithContext(context.Background()) }
+func (s *RootScope) ShutdownWithContext(ctx context.Context) map[string]error {
 	defer func() {
 		if s.healthCheckPool != nil {
 			s.healthCheckPool.stop()
@@ -142,14 +142,14 @@ func (s *RootScope) CloneWithOpts(opts *InjectorOpts) *RootScope {
 // ShutdownOnSignals listens for signals defined in signals parameter in order to graceful stop service.
 // It will block until receiving any of these signal.
 // If no signal is provided in signals parameter, syscall.SIGTERM and os.Interrupt will be added as default signal.
-func (s *RootScope) ShutdownOnSignals(signals ...os.Signal) (os.Signal, error) {
+func (s *RootScope) ShutdownOnSignals(signals ...os.Signal) (os.Signal, map[string]error) {
 	return s.ShutdownOnSignalsWithContext(context.Background(), signals...)
 }
 
 // ShutdownOnSignalsWithContext listens for signals defined in signals parameter in order to graceful stop service.
 // It will block until receiving any of these signal.
 // If no signal is provided in signals parameter, syscall.SIGTERM and os.Interrupt will be added as default signal.
-func (s *RootScope) ShutdownOnSignalsWithContext(ctx context.Context, signals ...os.Signal) (os.Signal, error) {
+func (s *RootScope) ShutdownOnSignalsWithContext(ctx context.Context, signals ...os.Signal) (os.Signal, map[string]error) {
 	// Make sure there is at least syscall.SIGTERM and os.Interrupt as a signal
 	if len(signals) < 1 {
 		signals = append(signals, syscall.SIGTERM, os.Interrupt)

scope.go

@@ -212,25 +212,24 @@ func (s *Scope) asyncHealthCheckWithContext(ctx context.Context) map[string]<-ch
 }
 
 // Shutdown shutdowns the scope and all its children.
-func (s *Scope) Shutdown() error {
+func (s *Scope) Shutdown() map[string]error {
 	return s.ShutdownWithContext(context.Background())
 }
 
 // ShutdownWithContext shutdowns the scope and all its children.
-func (s *Scope) ShutdownWithContext(ctx context.Context) error {
+func (s *Scope) ShutdownWithContext(ctx context.Context) map[string]error {
 	s.mu.RLock()
 	children := s.childScopes
 	invocations := invertMap(s.orderedInvocation)
 	s.mu.RUnlock()
 
 	s.logf("requested shutdown")
 
+	err := map[string]error{}
+
 	// first shutdown children
 	for k, child := range children {
-		err := child.Shutdown()
-		if err != nil {
-			return err
-		}
+		err = mergeMaps(err, child.Shutdown())
 
 		s.mu.Lock()
 		delete(s.childScopes, k) // scope is removed from DI container
@@ -244,15 +243,12 @@ func (s *Scope) ShutdownWithContext(ctx context.Context) error {
 			continue
 		}
 
-		err := s.serviceShutdown(ctx, name)
-		if err != nil {
-			return err
-		}
+		err[name] = s.serviceShutdown(ctx, name)
 	}
 
 	s.logf("shutdowned services")
 
-	return nil
+	return err
 }
 
 func (s *Scope) clone(root *RootScope, parent *Scope) *Scope {

scope_test.go

@@ -411,7 +411,16 @@ func TestScope_HealthCheckWithContext(t *testing.T) {
 }
 
 func TestScope_Shutdown(t *testing.T) {
-	// @TODO
+	is := assert.New(t)
+
+	i := New()
+
+	ProvideNamedValue(i, "lazy-ok", &lazyTestShutdownerOK{})
+	ProvideNamedValue(i, "lazy-ko", &lazyTestShutdownerKO{})
+	_, _ = InvokeNamed[*lazyTestShutdownerOK](i, "lazy-ok")
+	_, _ = InvokeNamed[*lazyTestShutdownerKO](i, "lazy-ko")
+
+	is.EqualValues(map[string]error{"lazy-ok": nil, "lazy-ko": assert.AnError}, i.Shutdown())
 }
 
 // @TODO: missing tests for context
@@ -426,11 +435,11 @@ func TestScope_ShutdownWithContext(t *testing.T) {
 	child2a := child1.Scope("child2a")
 	child2b := child1.Scope("child2b")
 
-	provider1 := func(i Injector) (*lazyTestHeathcheckerOK, error) {
-		return &lazyTestHeathcheckerOK{foobar: "foobar"}, nil
+	provider1 := func(i Injector) (*lazyTestShutdownerOK, error) {
+		return &lazyTestShutdownerOK{foobar: "foobar"}, nil
 	}
-	provider2 := func(i Injector) (*lazyTestHeathcheckerKO, error) {
-		return &lazyTestHeathcheckerKO{foobar: "foobar"}, nil
+	provider2 := func(i Injector) (*lazyTestShutdownerKO, error) {
+		return &lazyTestShutdownerKO{foobar: "foobar"}, nil
 	}
 
 	rootScope.serviceSet("root-a", newServiceLazy("root-a", provider2))
@@ -439,39 +448,39 @@ func TestScope_ShutdownWithContext(t *testing.T) {
 	child2a.serviceSet("child2a-b", newServiceLazy("child2a-b", provider2))
 	child2b.serviceSet("child2b-a", newServiceLazy("child2b-a", provider2))
 
-	_, _ = invokeByName[*lazyTestHeathcheckerKO](rootScope, "root-a")
-	_, _ = invokeByName[*lazyTestHeathcheckerOK](child1, "child1-a")
-	_, _ = invokeByName[*lazyTestHeathcheckerOK](child2a, "child2a-a")
-	_, _ = invokeByName[*lazyTestHeathcheckerKO](child2a, "child2a-b")
-	_, _ = invokeByName[*lazyTestHeathcheckerKO](child2b, "child2b-a")
+	_, _ = invokeByName[*lazyTestShutdownerKO](rootScope, "root-a")
+	_, _ = invokeByName[*lazyTestShutdownerOK](child1, "child1-a")
+	_, _ = invokeByName[*lazyTestShutdownerOK](child2a, "child2a-a")
+	_, _ = invokeByName[*lazyTestShutdownerKO](child2a, "child2a-b")
+	_, _ = invokeByName[*lazyTestShutdownerKO](child2b, "child2b-a")
 
 	// from rootScope POV
-	is.Equal(assert.AnError, rootScope.serviceHealthCheck(ctx, "root-a"))
-	is.ErrorContains(rootScope.serviceHealthCheck(ctx, "child1-a"), "could not find service")
-	is.ErrorContains(rootScope.serviceHealthCheck(ctx, "child2a-a"), "could not find service")
-	is.ErrorContains(rootScope.serviceHealthCheck(ctx, "child2a-b"), "could not find service")
-	is.ErrorContains(rootScope.serviceHealthCheck(ctx, "child2b-a"), "could not find service")
+	is.Equal(assert.AnError, rootScope.serviceShutdown(ctx, "root-a"))
+	is.ErrorContains(rootScope.serviceShutdown(ctx, "child1-a"), "could not find service")
+	is.ErrorContains(rootScope.serviceShutdown(ctx, "child2a-a"), "could not find service")
+	is.ErrorContains(rootScope.serviceShutdown(ctx, "child2a-b"), "could not find service")
+	is.ErrorContains(rootScope.serviceShutdown(ctx, "child2b-a"), "could not find service")
 
 	// from child1 POV
-	is.ErrorContains(child1.serviceHealthCheck(ctx, "root-a"), "could not find service")
-	is.Equal(nil, child1.serviceHealthCheck(ctx, "child1-a"))
-	is.ErrorContains(child1.serviceHealthCheck(ctx, "child2a-a"), "could not find service")
-	is.ErrorContains(child1.serviceHealthCheck(ctx, "child2a-b"), "could not find service")
-	is.ErrorContains(child1.serviceHealthCheck(ctx, "child2b-a"), "could not find service")
+	is.ErrorContains(child1.serviceShutdown(ctx, "root-a"), "could not find service")
+	is.Equal(nil, child1.serviceShutdown(ctx, "child1-a"))
+	is.ErrorContains(child1.serviceShutdown(ctx, "child2a-a"), "could not find service")
+	is.ErrorContains(child1.serviceShutdown(ctx, "child2a-b"), "could not find service")
+	is.ErrorContains(child1.serviceShutdown(ctx, "child2b-a"), "could not find service")
 
 	// from child2a POV
-	is.ErrorContains(child2a.serviceHealthCheck(ctx, "root-a"), "could not find service")
-	is.ErrorContains(child2a.serviceHealthCheck(ctx, "child1-a"), "could not find service")
-	is.Equal(nil, child2a.serviceHealthCheck(ctx, "child2a-a"))
-	is.Equal(assert.AnError, child2a.serviceHealthCheck(ctx, "child2a-b"))
-	is.ErrorContains(child2a.serviceHealthCheck(ctx, "child2b-a"), "could not find service")
+	is.ErrorContains(child2a.serviceShutdown(ctx, "root-a"), "could not find service")
+	is.ErrorContains(child2a.serviceShutdown(ctx, "child1-a"), "could not find service")
+	is.Equal(nil, child2a.serviceShutdown(ctx, "child2a-a"))
+	is.Equal(assert.AnError, child2a.serviceShutdown(ctx, "child2a-b"))
+	is.ErrorContains(child2a.serviceShutdown(ctx, "child2b-a"), "could not find service")
 
 	// from child2b POV
-	is.ErrorContains(child2b.serviceHealthCheck(ctx, "root-a"), "could not find service")
-	is.ErrorContains(child2b.serviceHealthCheck(ctx, "child1-a"), "could not find service")
-	is.ErrorContains(child2b.serviceHealthCheck(ctx, "child2a-a"), "could not find service")
-	is.ErrorContains(child2b.serviceHealthCheck(ctx, "child2a-b"), "could not find service")
-	is.Equal(assert.AnError, child2b.serviceHealthCheck(ctx, "child2b-a"))
+	is.ErrorContains(child2b.serviceShutdown(ctx, "root-a"), "could not find service")
+	is.ErrorContains(child2b.serviceShutdown(ctx, "child1-a"), "could not find service")
+	is.ErrorContains(child2b.serviceShutdown(ctx, "child2a-a"), "could not find service")
+	is.ErrorContains(child2b.serviceShutdown(ctx, "child2a-b"), "could not find service")
+	is.Equal(assert.AnError, child2b.serviceShutdown(ctx, "child2b-a"))
 }
 
 func TestScope_clone(t *testing.T) {
@@ -531,7 +540,7 @@ func TestScope_serviceHealthCheck(t *testing.T) {
 	_, _ = invokeByName[int](child3, "child3-a")
 
 	is.ElementsMatch([]EdgeService{newEdgeService(child3.id, child3.name, "child3-a"), newEdgeService(child2a.id, child2a.name, "child2a-a"), newEdgeService(child2a.id, child2a.name, "child2a-b"), newEdgeService(child1.id, child1.name, "child1-a")}, child3.ListInvokedServices())
-	is.Nil(child1.Shutdown())
+	is.EqualValues(map[string]error{"child1-a": nil, "child2a-a": nil, "child2a-b": nil, "child2b-a": nil, "child3-a": nil}, child1.Shutdown())
 	is.ElementsMatch([]EdgeService{}, child3.ListInvokedServices())
 }
 

utils.go

@@ -86,6 +86,18 @@ func filter[V any](collection []V, predicate func(item V, index int) bool) []V {
 	return result
 }
 
+func mergeMaps[K comparable, V any](ins ...map[K]V) map[K]V {
+	out := map[K]V{}
+
+	for _, in := range ins {
+		for k, v := range in {
+			out[k] = v
+		}
+	}
+
+	return out
+}
+
 func invertMap[K comparable, V comparable](in map[K]V) map[V]K {
 	out := map[V]K{}
 

utils_test.go

@@ -97,6 +97,18 @@ func TestUtilsMap(t *testing.T) {
 	is.Equal(result2, []string{"1", "2", "3", "4"})
 }
 
+func TestUtilsMergeMaps(t *testing.T) {
+	t.Parallel()
+	is := assert.New(t)
+
+	result1 := mergeMaps(map[string]int{"a": 1, "b": 2, "c": 3}, map[string]int{"c": 4, "d": 5, "e": 6})
+	result2 := mergeMaps[string, int]()
+
+	is.Equal(len(result1), 5)
+	is.Equal(len(result2), 0)
+	is.Equal(result1, map[string]int{"a": 1, "b": 2, "c": 4, "d": 5, "e": 6})
+}
+
 func TestUtilsInvertMap(t *testing.T) {
 	t.Parallel()
 	is := assert.New(t)

virtual_scope.go

@@ -30,8 +30,8 @@ func (s *virtualScope) HealthCheck() map[string]error          { return s.self.H
 func (s *virtualScope) HealthCheckWithContext(ctx context.Context) map[string]error {
 	return s.self.HealthCheckWithContext(ctx)
 }
-func (s *virtualScope) Shutdown() error { return s.self.Shutdown() }
-func (s *virtualScope) ShutdownWithContext(ctx context.Context) error {
+func (s *virtualScope) Shutdown() map[string]error { return s.self.Shutdown() }
+func (s *virtualScope) ShutdownWithContext(ctx context.Context) map[string]error {
 	return s.self.ShutdownWithContext(ctx)
 }
 func (s *virtualScope) clone(r *RootScope, p *Scope) *Scope              { return s.self.clone(r, p) }