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.

mlog/logr.go

@@ -60,6 +60,7 @@ func logrAddTargets(logger *logr.Logger, targets LogTargetCfg) error {
 			continue
 		}
 		if target != nil {
+			target.SetName(name)
 			lgr.AddTarget(target)
 		}
 	}
@@ -152,15 +153,18 @@ func newFileTarget(name string, t *LogTarget, filter logr.Filter, formatter logr
 	if err := json.Unmarshal(t.Options, options); err != nil {
 		return nil, err
 	}
+	return newFileTargetWithOpts(name, t, target.FileOptions(*options), filter, formatter)
+}
 
-	if options.Filename == "" {
+func newFileTargetWithOpts(name string, t *LogTarget, opts target.FileOptions, filter logr.Filter, formatter logr.Formatter) (logr.Target, error) {
+	if opts.Filename == "" {
 		return nil, fmt.Errorf("missing 'Filename' option for target %s", name)
 	}
-	if err := checkFileWritable(options.Filename); err != nil {
+	if err := checkFileWritable(opts.Filename); err != nil {
 		return nil, fmt.Errorf("error writing to 'Filename' for target %s: %w", name, err)
 	}
 
-	newTarget := target.NewFileTarget(filter, formatter, target.FileOptions(*options), t.MaxQueueSize)
+	newTarget := target.NewFileTarget(filter, formatter, opts, t.MaxQueueSize)
 	return newTarget, nil
 }
 
@@ -222,3 +226,22 @@ func zapToLogr(zapFields []Field) logr.Fields {
 	}
 	return logr.Fields(encoder.Fields)
 }
+
+// mlogLevelToLogrLevel converts a mlog logger level to
+// an array of discrete Logr levels.
+func mlogLevelToLogrLevels(level string) []LogLevel {
+	levels := make([]LogLevel, 0)
+	levels = append(levels, LvlError, LvlPanic, LvlFatal, LvlStdLog)
+
+	switch level {
+	case LevelDebug:
+		levels = append(levels, LvlDebug)
+		fallthrough
+	case LevelInfo:
+		levels = append(levels, LvlInfo)
+		fallthrough
+	case LevelWarn:
+		levels = append(levels, LvlWarn)
+	}
+	return levels
+}