MM-62378: Initialize status and session cache before loading license (#29686)

* MM-62378: Initialize status and session cache before loading license

ps.LoadLicense could end up calling InvalidateAllCaches. Therefore,
we need to intialize those caches before calling LoadLicense
to prevent a panic from happening.

While here, we also remove some unused code.

https://mattermost.atlassian.net/browse/MM-62378
```release-note
NONE
```

* fix lint errors

```release-note
NONE
```

* fix test

```release-note
NONE
```

server/channels/app/platform/cluster_handlers.go

@@ -6,7 +6,6 @@ package platform
 import (
 	"bytes"
 	"encoding/json"
-	"fmt"
 
 	"github.com/mattermost/mattermost/server/public/model"
 	"github.com/mattermost/mattermost/server/public/shared/mlog"
@@ -31,19 +30,6 @@ func (ps *PlatformService) RegisterClusterMessageHandler(ev model.ClusterEvent,
 	ps.additionalClusterHandlers[ev] = h
 }
 
-// ClusterHandlersPreCheck checks whether the platform service is ready to handle cluster messages.
-func (ps *PlatformService) ClusterHandlersPreCheck() error {
-	if ps.Store == nil {
-		return fmt.Errorf("could not find store")
-	}
-
-	if ps.statusCache == nil {
-		return fmt.Errorf("could not find status cache")
-	}
-
-	return nil
-}
-
 func (ps *PlatformService) ClusterPublishHandler(msg *model.ClusterMessage) {
 	event, err := model.WebSocketEventFromJSON(bytes.NewReader(msg.Data))
 	if err != nil {

server/channels/app/platform/service.go

@@ -266,7 +266,37 @@ func New(sc ServiceConfig, options ...Option) (*PlatformService, error) {
 		return nil, fmt.Errorf("cannot create store: %w", err)
 	}
 
-	// Step 7: Init License
+	// Step 7: initialize status and session cache.
+	// We need to do this because ps.LoadLicense() called in step 8, could
+	// end up calling InvalidateAllCaches, so the status and session caches
+	// need to be initialized before that.
+
+	// Note: we hardcode the session and status cache to LRU because they lead
+	// to a lot of SCAN calls in case of Redis. We could potentially have a
+	// reverse mapping to avoid the scan, but this needs more complicated code.
+	// Leaving this for now.
+	ps.statusCache, err = cache.NewProvider().NewCache(&cache.CacheOptions{
+		Name:           "Status",
+		Size:           model.StatusCacheSize,
+		Striped:        true,
+		StripedBuckets: max(runtime.NumCPU()-1, 1),
+		DefaultExpiry:  30 * time.Minute,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("unable to create status cache: %w", err)
+	}
+
+	ps.sessionCache, err = cache.NewProvider().NewCache(&cache.CacheOptions{
+		Name:           "Session",
+		Size:           model.SessionCacheSize,
+		Striped:        true,
+		StripedBuckets: max(runtime.NumCPU()-1, 1),
+	})
+	if err != nil {
+		return nil, fmt.Errorf("could not create session cache: %w", err)
+	}
+
+	// Step 8: Init License
 	if model.BuildEnterpriseReady == "true" {
 		ps.LoadLicense()
 	}
@@ -280,7 +310,7 @@ func New(sc ServiceConfig, options ...Option) (*PlatformService, error) {
 		return nil, fmt.Errorf("Redis cannot be used in an instance without a license or a license without clustering")
 	}
 
-	// Step 8: Initialize filestore
+	// Step 9: Initialize filestore
 	if ps.filestore == nil {
 		insecure := ps.Config().ServiceSettings.EnableInsecureOutgoingConnections
 		backend, err2 := filestore.NewFileBackend(filestore.NewFileBackendSettingsFromConfig(&ps.Config().FileSettings, license != nil && *license.Features.Compliance, insecure != nil && *insecure))
@@ -304,33 +334,7 @@ func New(sc ServiceConfig, options ...Option) (*PlatformService, error) {
 		}
 	}
 
-	// Note: we hardcode the session and status cache to LRU because they lead
+	// Step 10: Init Metrics Server depends on step 6 (store) and 8 (license)
-	// to a lot of SCAN calls in case of Redis. We could potentially have a
-	// reverse mapping to avoid the scan, but this needs more complicated code.
-	// Leaving this for now.
-
-	ps.statusCache, err = cache.NewProvider().NewCache(&cache.CacheOptions{
-		Name:           "Status",
-		Size:           model.StatusCacheSize,
-		Striped:        true,
-		StripedBuckets: max(runtime.NumCPU()-1, 1),
-		DefaultExpiry:  30 * time.Minute,
-	})
-	if err != nil {
-		return nil, fmt.Errorf("unable to create status cache: %w", err)
-	}
-
-	ps.sessionCache, err = cache.NewProvider().NewCache(&cache.CacheOptions{
-		Name:           "Session",
-		Size:           model.SessionCacheSize,
-		Striped:        true,
-		StripedBuckets: max(runtime.NumCPU()-1, 1),
-	})
-	if err != nil {
-		return nil, fmt.Errorf("could not create session cache: %w", err)
-	}
-
-	// Step 9: Init Metrics Server depends on step 6 (store) and 7 (license)
 	if ps.startMetrics {
 		if mErr := ps.resetMetrics(); mErr != nil {
 			return nil, mErr
@@ -345,7 +349,7 @@ func New(sc ServiceConfig, options ...Option) (*PlatformService, error) {
 		})
 	}
 
-	// Step 10: Init AsymmetricSigningKey depends on step 6 (store)
+	// Step 11: Init AsymmetricSigningKey depends on step 6 (store)
 	if err = ps.EnsureAsymmetricSigningKey(); err != nil {
 		return nil, fmt.Errorf("unable to ensure asymmetric signing key: %w", err)
 	}
@@ -499,10 +503,6 @@ func (ps *PlatformService) CacheProvider() cache.Provider {
 	return ps.cacheProvider
 }
 
-func (ps *PlatformService) StatusCache() cache.Cache {
-	return ps.statusCache
-}
-
 // SetSqlStore is used for plugin testing
 func (ps *PlatformService) SetSqlStore(s *sqlstore.SqlStore) {
 	ps.sqlStore = s

server/channels/app/platform/service_test.go

@@ -21,6 +21,41 @@ import (
 	"github.com/mattermost/mattermost/server/v8/einterfaces/mocks"
 )
 
+// A copy of validTestLicense from channels/utils/license_test.go
+var validTestLicense = []byte("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")
+
+func TestSetLicenseOnStart(t *testing.T) {
+	oldValue := model.BuildEnterpriseReady
+	defer func() { model.BuildEnterpriseReady = oldValue }()
+	model.BuildEnterpriseReady = "true"
+
+	cfg := model.Config{}
+	cfg.SetDefaults()
+
+	f, err := os.CreateTemp("", "TestSetLicenseOnStart")
+	require.NoError(t, err)
+	defer os.Remove(f.Name())
+	require.NoError(t, os.WriteFile(f.Name(), validTestLicense, 0777))
+
+	*cfg.ServiceSettings.LicenseFileLocation = f.Name()
+
+	driverName := os.Getenv("MM_SQLSETTINGS_DRIVERNAME")
+	if driverName == "" {
+		driverName = model.DatabaseDriverPostgres
+	}
+	cfg.SqlSettings = *storetest.MakeSqlSettings(driverName, false)
+
+	configStore := config.NewTestMemoryStore()
+	_, _, err = configStore.Set(&cfg)
+	require.NoError(t, err)
+	// It should not panic when ps.LoadLicense gets called from platform.New
+	_, err = New(
+		ServiceConfig{},
+		ConfigStore(configStore),
+	)
+	require.NoError(t, err)
+}
+
 func TestReadReplicaDisabledBasedOnLicense(t *testing.T) {
 	cfg := model.Config{}
 	cfg.SetDefaults()