MM-27744 disable Zap for unit tests. (#15398)

MM-27744 disable Zap for unit tests.

Zap has no concept of shutdown or close. Zap is only shutdown when the app exits. Not a problem for console logging, but when creating a new Zap logger that outputs to files on every unit test, that leaves no easy way to clean up until process exit. Depending on what else is running this can exhaust all file handles and cause unit tests to fail.

Zap is now disabled unit tests and uses Logr instead, regardless of config settings. `make test-server` peak file handle usage dropped from ~5K to less than 100.

app/admin.go

@@ -4,6 +4,7 @@
 package app
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -59,6 +60,10 @@ func (s *Server) GetLogsSkipSend(page, perPage int) ([]string, *model.AppError)
 	var lines []string
 
 	if *s.Config().LogSettings.EnableFile {
+		timeoutCtx, timeoutCancel := context.WithTimeout(context.Background(), mlog.DefaultFlushTimeout)
+		defer timeoutCancel()
+		mlog.Flush(timeoutCtx)
+
 		logFile := utils.GetLogFileLocation(*s.Config().LogSettings.FileLocation)
 		file, err := os.Open(logFile)
 		if err != nil {

app/main_test.go

@@ -6,6 +6,7 @@ package app
 import (
 	"testing"
 
+	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/testlib"
 )
 
@@ -17,6 +18,8 @@ func TestMain(m *testing.M) {
 		EnableResources: true,
 	}
 
+	mlog.DisableZap()
+
 	mainHelper = testlib.NewMainHelperWithOptions(&options)
 	defer mainHelper.Close()
 

app/server.go

@@ -115,20 +115,20 @@ type Server struct {
 
 	newStore func() store.Store
 
-	htmlTemplateWatcher            *utils.HTMLTemplateWatcher
-	sessionCache                   cache.Cache
-	seenPendingPostIdsCache        cache.Cache
-	statusCache                    cache.Cache
-	configListenerId               string
-	licenseListenerId              string
-	logListenerId                  string
-	clusterLeaderListenerId        string
-	searchConfigListenerId         string
-	searchLicenseListenerId        string
-	loggerMetricsLicenseListenerId string
-	configStore                    config.Store
-	asymmetricSigningKey           *ecdsa.PrivateKey
-	postActionCookieSecret         []byte
+	htmlTemplateWatcher     *utils.HTMLTemplateWatcher
+	sessionCache            cache.Cache
+	seenPendingPostIdsCache cache.Cache
+	statusCache             cache.Cache
+	configListenerId        string
+	licenseListenerId       string
+	logListenerId           string
+	clusterLeaderListenerId string
+	searchConfigListenerId  string
+	searchLicenseListenerId string
+	loggerLicenseListenerId string
+	configStore             config.Store
+	asymmetricSigningKey    *ecdsa.PrivateKey
+	postActionCookieSecret  []byte
 
 	advancedLogListenerCleanup func()
 
@@ -480,19 +480,11 @@ func NewServer(options ...Option) (*Server, error) {
 		}
 	}
 
-	if !allowAdvancedLogging {
-		timeoutCtx, cancelCtx := context.WithTimeout(context.Background(), time.Second*5)
-		defer cancelCtx()
-		mlog.Info("Shutting down advanced logging")
-		mlog.ShutdownAdvancedLogging(timeoutCtx)
-		if s.advancedLogListenerCleanup != nil {
-			s.advancedLogListenerCleanup()
-			s.advancedLogListenerCleanup = nil
-		}
-	}
-
+	s.removeUnlicensedLogTargets(license)
 	s.enableLoggingMetrics()
-	s.loggerMetricsLicenseListenerId = s.AddLicenseListener(func(oldLicense, newLicense *model.License) {
+
+	s.loggerLicenseListenerId = s.AddLicenseListener(func(oldLicense, newLicense *model.License) {
+		s.removeUnlicensedLogTargets(newLicense)
 		s.enableLoggingMetrics()
 	})
 
@@ -561,6 +553,7 @@ func (s *Server) AppOptions() []AppOption {
 	}
 }
 
+// initLogging initializes and configures the logger. This may be called more than once.
 func (s *Server) initLogging() error {
 	if s.Log == nil {
 		s.Log = mlog.NewLogger(utils.MloggerConfigFromLoggerConfig(&s.Config().LogSettings, utils.GetLogFileLocation))
@@ -578,6 +571,9 @@ func (s *Server) initLogging() error {
 	// Use this app logger as the global logger (eventually remove all instances of global logging)
 	mlog.InitGlobalLogger(s.Log)
 
+	if s.logListenerId != "" {
+		s.RemoveConfigListener(s.logListenerId)
+	}
 	s.logListenerId = s.AddConfigListener(func(_, after *model.Config) {
 		s.Log.ChangeLevels(utils.MloggerConfigFromLoggerConfig(&after.LogSettings, utils.GetLogFileLocation))
 
@@ -633,13 +629,27 @@ func (s *Server) initLogging() error {
 	return nil
 }
 
+func (s *Server) removeUnlicensedLogTargets(license *model.License) {
+	if license != nil && *license.Features.AdvancedLogging {
+		// advanced logging enabled via license; no need to remove any targets
+		return
+	}
+
+	timeoutCtx, cancelCtx := context.WithTimeout(context.Background(), time.Second*10)
+	defer cancelCtx()
+
+	mlog.RemoveTargets(timeoutCtx, func(ti mlog.TargetInfo) bool {
+		return ti.Type != "*target.Writer" && ti.Type != "*target.File"
+	})
+}
+
 func (s *Server) enableLoggingMetrics() {
 	if s.Metrics == nil {
 		return
 	}
 
 	if err := mlog.EnableMetrics(s.Metrics.GetLoggerMetricsCollector()); err != nil {
-		mlog.Debug("Failed to enable advanced logging metrics", mlog.Err(err))
+		mlog.Error("Failed to enable advanced logging metrics", mlog.Err(err))
 	} else {
 		mlog.Debug("Advanced logging metrics enabled")
 	}
@@ -677,7 +687,7 @@ func (s *Server) Shutdown() error {
 	s.HubStop()
 	s.ShutDownPlugins()
 	s.RemoveLicenseListener(s.licenseListenerId)
-	s.RemoveLicenseListener(s.loggerMetricsLicenseListenerId)
+	s.RemoveLicenseListener(s.loggerLicenseListenerId)
 	s.RemoveClusterLeaderChangedListener(s.clusterLeaderListenerId)
 
 	if s.tracer != nil {

app/server_test.go

@@ -304,6 +304,10 @@ func TestPanicLog(t *testing.T) {
 		require.NoError(t, os.Remove(tmpfile.Name()))
 	}()
 
+	// This test requires Zap file target for now.
+	mlog.EnableZap()
+	defer mlog.DisableZap()
+
 	// Creating logger to log to console and temp file
 	logger := mlog.NewLogger(&mlog.LoggerConfiguration{
 		EnableConsole: true,

app/slashcommands/main_test.go

@@ -6,6 +6,7 @@ package slashcommands
 import (
 	"testing"
 
+	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/testlib"
 )
 
@@ -17,6 +18,8 @@ func TestMain(m *testing.M) {
 		EnableResources: true,
 	}
 
+	mlog.DisableZap()
+
 	mainHelper = testlib.NewMainHelperWithOptions(&options)
 	defer mainHelper.Close()