review fixes

docs/user_guide/outputs/file_output.md

@@ -55,7 +55,6 @@ outputs:
      # list of processors to apply on the message before writing
     event-processors:
     # file rotation configuration
-    #   all fields are required if enabling file rotation
     rotation:
       max-size: 100 # size in megabytes
       max-age: 30 # max age in days
@@ -69,5 +68,3 @@ The file output can be used to write to file on the disk, to stdout or to stderr
 For a disk file, a file name is required.
 
 For stdout or stderr, only file-type is required.
-
-For rotation, all fields (other than `compress`) are required.

pkg/outputs/file/file_output.go

@@ -78,7 +78,7 @@ type Config struct {
 	EnableMetrics      bool           `mapstructure:"enable-metrics,omitempty"`
 	Debug              bool           `mapstructure:"debug,omitempty"`
 	CalculateLatency   bool           `mapstructure:"calculate-latency,omitempty"`
-	Rotation           RotationConfig `mapstructure:"rotation,omitempty"`
+	Rotation           rotationConfig `mapstructure:"rotation,omitempty"`
 }
 
 type file interface {
@@ -150,13 +150,6 @@ func (f *File) Init(ctx context.Context, name string, cfg map[string]interface{}
 	case "stderr":
 		f.file = os.Stderr
 	case "rotating":
-		err := f.cfg.Rotation.validateConfig()
-		if err != nil {
-			f.logger.Printf("failed to validate rotating configuration: %v", err)
-
-			return err
-		}
-
 		f.file = newRotatingFile(f.cfg)
 	default:
 	CRFILE:

pkg/outputs/file/rotating_file.go

@@ -1,34 +1,28 @@
 package file
 
 import (
-	"fmt"
-
 	"gopkg.in/natefinch/lumberjack.v2"
 )
 
 // RotationConfig manages configuration around file rotation
-type RotationConfig struct {
+type rotationConfig struct {
 	MaxSize    int  `mapstructure:"max-size,omitempty"`
 	MaxBackups int  `mapstructure:"max-backups,omitempty"`
 	MaxAge     int  `mapstructure:"max-age,omitempty"`
 	Compress   bool `mapstructure:"compress,omitempty"`
 }
 
-// validateConfig ensures all parameters are supplied
-func (rc *RotationConfig) validateConfig() error {
-	if rc.MaxSize == 0 {
-		return fmt.Errorf("Rotation.MaxSize is required if using type 'rotating'")
+func (r *rotationConfig) SetDefaults() {
+	if r.MaxSize == 0 {
+		r.MaxSize = 100
 	}
-
-	if rc.MaxBackups == 0 {
-		return fmt.Errorf("Rotation.MaxBackups is required if using type 'rotating'")
+	if r.MaxBackups == 0 {
+		r.MaxBackups = 3
 	}
 
-	if rc.MaxAge == 0 {
-		return fmt.Errorf("Rotation.MaxAge is required if using type 'rotating'")
+	if r.MaxAge == 0 {
+		r.MaxAge = 30
 	}
-
-	return nil
 }
 
 type rotatingFile struct {
@@ -37,6 +31,8 @@ type rotatingFile struct {
 
 // newRotatingFile initialize the lumberjack instance
 func newRotatingFile(cfg *Config) *rotatingFile {
+	cfg.Rotation.SetDefaults()
+
 	lj := lumberjack.Logger{
 		Filename:   cfg.FileName,
 		MaxSize:    cfg.Rotation.MaxSize,