MM-53879: Fix recursive loading of license (#24200)

There were multiple problems with loading of a license.

1. It was called from inside app/server.go and app/platform/service.go. The first one wasn't really needed anymore, so we remove it.

2. To make loading of a license work across a cluster, the license load action was attached along with the `InvalidateAllCachesSkipSend` method. But the problem with that was that it would even get called in the caller node as well, putting it in a recursive loop.

```
LoadLicense -> SaveLicense -> InvalidateAllCaches -> InvalidateAllCachesSkipSend -> LoadLicense
```

To fix this, we create a dedicated loadLicense cluster event and move it away from the `InvalidateAllCachesSkipSend` method. And then from the caller side, we just trigger this action.

3. We also remove the first call to check license expiration which would load the license again. This is unnecessary because if the license is expired, server wouldn't start at all.

While here, we also make some other improvements like removing unnecessary goroutine spawning while publishing websocket events. They are already handled asynchronously, so there is no need
to create a goroutine for that.

We also remove

```
ps.ReloadConfig()
ps.InvalidateAllCaches()
```

from requestTrialLicense as they are already called from inside `*PlatformService.SaveLicense`.

And lastly, we remove the `*model.AppError` return from `*PlatformService.InvalidateAllCaches` because there was nothing to return at all.

https://mattermost.atlassian.net/browse/MM-53879

```release-note
Fix several issues with loading of a license
```

server/channels/api4/system.go

@@ -317,11 +317,7 @@ func invalidateCaches(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	appErr := c.App.Srv().InvalidateAllCaches()
-	if appErr != nil {
-		c.Err = appErr
-		return
-	}
+	c.App.Srv().InvalidateAllCaches()
 
 	auditRec.Success()
 

server/channels/api4/user_test.go

@@ -3902,8 +3902,7 @@ func TestLoginWithLag(t *testing.T) {
 		_, _, err := th.Client.Login(context.Background(), th.BasicUser.Email, th.BasicUser.Password)
 		require.NoError(t, err)
 
-		appErr = th.App.Srv().InvalidateAllCaches()
-		require.Nil(t, appErr)
+		th.App.Srv().InvalidateAllCaches()
 
 		session, appErr := th.App.GetSession(th.Client.AuthToken)
 		require.Nil(t, appErr)

server/channels/app/admin.go

@@ -137,8 +137,8 @@ func (a *App) GetClusterStatus() []*model.ClusterInfo {
 	return infos
 }
 
-func (s *Server) InvalidateAllCaches() *model.AppError {
-	return s.platform.InvalidateAllCaches()
+func (s *Server) InvalidateAllCaches() {
+	s.platform.InvalidateAllCaches()
 }
 
 func (s *Server) InvalidateAllCachesSkipSend() {

server/channels/app/license.go

@@ -131,10 +131,6 @@ func (s *Server) License() *model.License {
 	return s.platform.License()
 }
 
-func (s *Server) LoadLicense() {
-	s.platform.LoadLicense()
-}
-
 func (s *Server) SaveLicense(licenseBytes []byte) (*model.License, *model.AppError) {
 	return s.platform.SaveLicense(licenseBytes)
 }

server/channels/app/license_test.go

@@ -1,109 +0,0 @@
-// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
-// See LICENSE.txt for license information.
-
-package app
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mattermost/mattermost/server/public/model"
-)
-
-func TestLoadLicense(t *testing.T) {
-	th := Setup(t)
-	defer th.TearDown()
-
-	th.App.Srv().LoadLicense()
-	require.Nil(t, th.App.Srv().License(), "shouldn't have a valid license")
-}
-
-func TestSaveLicense(t *testing.T) {
-	th := Setup(t)
-	defer th.TearDown()
-
-	b1 := []byte("junk")
-
-	_, err := th.App.Srv().SaveLicense(b1)
-	require.NotNil(t, err, "shouldn't have saved license")
-}
-
-func TestRemoveLicense(t *testing.T) {
-	th := Setup(t)
-	defer th.TearDown()
-
-	err := th.App.Srv().RemoveLicense()
-	require.Nil(t, err, "should have removed license")
-}
-
-func TestSetLicense(t *testing.T) {
-	th := Setup(t)
-	defer th.TearDown()
-
-	l1 := &model.License{}
-	l1.Features = &model.Features{}
-	l1.Customer = &model.Customer{}
-	l1.StartsAt = model.GetMillis() - 1000
-	l1.ExpiresAt = model.GetMillis() + 100000
-	ok := th.App.Srv().SetLicense(l1)
-	require.True(t, ok, "license should have worked")
-
-	l3 := &model.License{}
-	l3.Features = &model.Features{}
-	l3.Customer = &model.Customer{}
-	l3.StartsAt = model.GetMillis() + 10000
-	l3.ExpiresAt = model.GetMillis() + 100000
-	ok = th.App.Srv().SetLicense(l3)
-	require.True(t, ok, "license should have passed")
-}
-
-func TestGetSanitizedClientLicense(t *testing.T) {
-	th := Setup(t)
-	defer th.TearDown()
-
-	setLicense(th, nil)
-
-	m := th.App.Srv().GetSanitizedClientLicense()
-
-	_, ok := m["Name"]
-	assert.False(t, ok)
-	_, ok = m["SkuName"]
-	assert.False(t, ok)
-}
-
-func TestGenerateRenewalToken(t *testing.T) {
-	th := Setup(t)
-	defer th.TearDown()
-
-	t.Run("renewal token generated correctly", func(t *testing.T) {
-		setLicense(th, nil)
-		token, appErr := th.App.Srv().GenerateRenewalToken(JWTDefaultTokenExpiration)
-		require.Nil(t, appErr)
-		require.NotEmpty(t, token)
-	})
-
-	t.Run("return error if there is no active license", func(t *testing.T) {
-		th.App.Srv().SetLicense(nil)
-		_, appErr := th.App.Srv().GenerateRenewalToken(JWTDefaultTokenExpiration)
-		require.NotNil(t, appErr)
-	})
-}
-
-func setLicense(th *TestHelper, customer *model.Customer) {
-	l1 := &model.License{}
-	l1.Features = &model.Features{}
-	if customer != nil {
-		l1.Customer = customer
-	} else {
-		l1.Customer = &model.Customer{}
-		l1.Customer.Name = "TestName"
-		l1.Customer.Email = "test@example.com"
-	}
-	l1.SkuName = "SKU NAME"
-	l1.SkuShortName = "SKU SHORT NAME"
-	l1.StartsAt = model.GetMillis() - 1000
-	l1.ExpiresAt = model.GetMillis() + 100000
-	th.App.Srv().SetLicense(l1)
-}

server/channels/app/notification_test.go

@@ -98,8 +98,7 @@ func TestSendNotifications(t *testing.T) {
 
 	_, appErr = th.App.UpdateActive(th.Context, th.BasicUser2, false)
 	require.Nil(t, appErr)
-	appErr = th.App.Srv().InvalidateAllCaches()
-	require.Nil(t, appErr)
+	th.App.Srv().InvalidateAllCaches()
 
 	post3, appErr := th.App.CreatePostMissingChannel(th.Context, &model.Post{
 		UserId:    th.BasicUser.Id,

server/channels/app/oauth.go

@@ -113,9 +113,7 @@ func (a *App) DeleteOAuthApp(appID string) *model.AppError {
 		return model.NewAppError("DeleteOAuthApp", "app.oauth.delete_app.app_error", nil, "", http.StatusInternalServerError).Wrap(err)
 	}
 
-	if err := a.Srv().InvalidateAllCaches(); err != nil {
-		mlog.Warn("error in invalidating cache", mlog.Err(err))
-	}
+	a.Srv().InvalidateAllCaches()
 
 	return nil
 }

server/channels/app/platform/cluster_handlers.go

@@ -17,6 +17,7 @@ func (ps *PlatformService) RegisterClusterHandlers() {
 	ps.clusterIFace.RegisterClusterMessageHandler(model.ClusterEventPublish, ps.ClusterPublishHandler)
 	ps.clusterIFace.RegisterClusterMessageHandler(model.ClusterEventUpdateStatus, ps.ClusterUpdateStatusHandler)
 	ps.clusterIFace.RegisterClusterMessageHandler(model.ClusterEventInvalidateAllCaches, ps.ClusterInvalidateAllCachesHandler)
+	ps.clusterIFace.RegisterClusterMessageHandler(model.ClusterEventLoadLicense, ps.LoadLicenseClusterHandler)
 	ps.clusterIFace.RegisterClusterMessageHandler(model.ClusterEventInvalidateCacheForChannelMembersNotifyProps, ps.clusterInvalidateCacheForChannelMembersNotifyPropHandler)
 	ps.clusterIFace.RegisterClusterMessageHandler(model.ClusterEventInvalidateCacheForChannelByName, ps.clusterInvalidateCacheForChannelByNameHandler)
 	ps.clusterIFace.RegisterClusterMessageHandler(model.ClusterEventInvalidateCacheForUser, ps.clusterInvalidateCacheForUserHandler)
@@ -154,10 +155,27 @@ func (ps *PlatformService) InvalidateAllCachesSkipSend() {
 	ps.Store.Webhook().ClearCaches()
 
 	linkCache.Purge()
-	ps.LoadLicense()
 }
 
-func (ps *PlatformService) InvalidateAllCaches() *model.AppError {
+func (ps *PlatformService) LoadLicenseClusterHandler(_ *model.ClusterMessage) {
+	ps.loadLicense()
+}
+
+func (ps *PlatformService) TriggerLoadLicense() {
+	ps.loadLicense()
+
+	if ps.clusterIFace != nil {
+		msg := &model.ClusterMessage{
+			Event:            model.ClusterEventLoadLicense,
+			SendType:         model.ClusterSendReliable,
+			WaitForAllToSend: true,
+		}
+
+		ps.clusterIFace.SendClusterMessage(msg)
+	}
+}
+
+func (ps *PlatformService) InvalidateAllCaches() {
 	ps.InvalidateAllCachesSkipSend()
 
 	if ps.clusterIFace != nil {
@@ -170,6 +188,4 @@ func (ps *PlatformService) InvalidateAllCaches() *model.AppError {
 
 		ps.clusterIFace.SendClusterMessage(msg)
 	}
-
-	return nil
 }

server/channels/app/platform/license.go

@@ -46,7 +46,7 @@ func (ps *PlatformService) License() *model.License {
 	return ps.licenseValue.Load()
 }
 
-func (ps *PlatformService) LoadLicense() {
+func (ps *PlatformService) loadLicense() {
 	// ENV var overrides all other sources of license.
 	licenseStr := os.Getenv(LicenseEnv)
 	if licenseStr != "" {
@@ -326,9 +326,6 @@ func (ps *PlatformService) RequestTrialLicense(trialRequest *model.TrialLicenseR
 		return err
 	}
 
-	ps.ReloadConfig()
-	ps.InvalidateAllCaches()
-
 	return nil
 }
 

server/channels/app/platform/license_test.go

@@ -12,14 +12,6 @@ import (
 	"github.com/mattermost/mattermost/server/public/model"
 )
 
-func TestLoadLicense(t *testing.T) {
-	th := Setup(t)
-	defer th.TearDown()
-
-	th.Service.LoadLicense()
-	require.Nil(t, th.Service.License(), "shouldn't have a valid license")
-}
-
 func TestSaveLicense(t *testing.T) {
 	th := Setup(t)
 	defer th.TearDown()

server/channels/app/platform/service.go

@@ -292,7 +292,7 @@ func New(sc ServiceConfig, options ...Option) (*PlatformService, error) {
 
 	// Step 7: Init License
 	if model.BuildEnterpriseReady == "true" {
-		ps.LoadLicense()
+		ps.TriggerLoadLicense()
 	}
 
 	// Step 8: Init Metrics Server depends on step 6 (store) and 7 (license)
@@ -353,9 +353,7 @@ func (ps *PlatformService) Start() error {
 		message := model.NewWebSocketEvent(model.WebsocketEventConfigChanged, "", "", "", nil, "")
 
 		message.Add("config", ps.ClientConfigWithComputed())
-		ps.Go(func() {
-			ps.Publish(message)
-		})
+		ps.Publish(message)
 
 		if err := ps.ReconfigureLogger(); err != nil {
 			mlog.Error("Error re-configuring logging after config change", mlog.Err(err))
@@ -368,9 +366,7 @@ func (ps *PlatformService) Start() error {
 
 		message := model.NewWebSocketEvent(model.WebsocketEventLicenseChanged, "", "", "", nil, "")
 		message.Add("license", ps.GetSanitizedClientLicense())
-		ps.Go(func() {
-			ps.Publish(message)
-		})
+		ps.Publish(message)
 
 	})
 	return nil

server/channels/app/server.go

@@ -208,7 +208,6 @@ func NewServer(options ...Option) (*Server, error) {
 	// Depends on step 1 (s.Platform must be non-nil)
 	s.initEnterprise()
 
-	// Needed to run before loading license.
 	s.userService, err = users.New(users.ServiceConfig{
 		UserStore:    s.Store().User(),
 		SessionStore: s.Store().Session(),
@@ -222,11 +221,6 @@ func NewServer(options ...Option) (*Server, error) {
 		return nil, errors.Wrapf(err, "unable to create users service")
 	}
 
-	if model.BuildEnterpriseReady == "true" {
-		// Dependent on user service
-		s.LoadLicense()
-	}
-
 	s.licenseWrapper = &licenseWrapper{
 		srv: s,
 	}
@@ -1383,8 +1377,6 @@ func (s *Server) sendLicenseUpForRenewalEmail(users map[string]*model.User, lice
 }
 
 func (s *Server) doLicenseExpirationCheck() {
-	s.LoadLicense()
-
 	// This takes care of a rare edge case reported here https://mattermost.atlassian.net/browse/MM-40962
 	// To reproduce that case locally, attach a license to a server that was started with enterprise enabled
 	// Then restart using BUILD_ENTERPRISE=false make restart-server to enter Team Edition
@@ -1394,7 +1386,6 @@ func (s *Server) doLicenseExpirationCheck() {
 	}
 
 	license := s.License()
-
 	if license == nil {
 		mlog.Debug("License cannot be found.")
 		return

server/cmd/mattermost/commands/init.go

@@ -49,10 +49,6 @@ func initDBCommandContext(configDSN string, readOnlyConfigStore bool, options ..
 
 	a := app.New(app.ServerConnector(s.Channels()))
 
-	if model.BuildEnterpriseReady == "true" {
-		a.Srv().LoadLicense()
-	}
-
 	return a, nil
 }
 

server/cmd/mattermost/commands/jobserver.go

@@ -41,8 +41,6 @@ func jobserverCmdF(command *cobra.Command, args []string) error {
 	}
 	defer a.Srv().Shutdown()
 
-	a.Srv().LoadLicense()
-
 	// Run jobs
 	mlog.Info("Starting Mattermost job server")
 	defer mlog.Info("Stopped Mattermost job server")

server/public/model/cluster_message.go

@@ -9,6 +9,7 @@ const (
 	ClusterEventPublish                                     ClusterEvent = "publish"
 	ClusterEventUpdateStatus                                ClusterEvent = "update_status"
 	ClusterEventInvalidateAllCaches                         ClusterEvent = "inv_all_caches"
+	ClusterEventLoadLicense                                 ClusterEvent = "load_license"
 	ClusterEventInvalidateCacheForReactions                 ClusterEvent = "inv_reactions"
 	ClusterEventInvalidateCacheForChannelMembersNotifyProps ClusterEvent = "inv_channel_members_notify_props"
 	ClusterEventInvalidateCacheForChannelByName             ClusterEvent = "inv_channel_name"