Better log messages

examples/consumer/sns/consumer.go

@@ -8,7 +8,7 @@ import (
 )
 
 func main() {
-	consumer := sns.NewConsumer(sns.ConsumerConfig{
+	consumer := sns.MustNewConsumer(&sns.ConsumerConfig{
 		AccessKey: "",
 		SecretKey: "",
 		Region:    "us-east-1",

sns/consumer.go

@@ -15,6 +15,12 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+var (
+	ErrEmptyConig     = errors.New("empty config")
+	ErrEmptyAccessKey = errors.New("empty access key")
+	ErrEmptySecretKey = errors.New("empty secret key")
+)
+
 type snsMessagePayload struct {
 	Message          string    `json:"Message"`
 	MessageID        string    `json:"MessageId"`
@@ -38,6 +44,36 @@ type ConsumerConfig struct {
 	QueueUrl            string
 }
 
+func (c *ConsumerConfig) setDefaults() {
+	if c.VisibilityTimeout == 0 {
+		c.VisibilityTimeout = 20
+	}
+
+	if c.WaitTimeSeconds == 0 {
+		c.WaitTimeSeconds = 20
+	}
+
+	if c.MaxNumberOfMessages == 0 {
+		c.MaxNumberOfMessages = 5
+	}
+}
+
+func (c *ConsumerConfig) isValid() error {
+	if c == nil {
+		return ErrEmptyConig
+	}
+
+	if c.AccessKey == "" {
+		return ErrEmptyAccessKey
+	}
+
+	if c.SecretKey == "" {
+		return ErrEmptySecretKey
+	}
+
+	return nil
+}
+
 type handler struct {
 	action  string
 	fn      messaging.EventHandler
@@ -47,30 +83,28 @@ type handler struct {
 type consumer struct {
 	sqs                 *sqs.SQS
 	stop                chan bool
-	config              ConsumerConfig
+	config              *ConsumerConfig
 	receiveMessageInput *sqs.ReceiveMessageInput
 	m                   sync.RWMutex
 	handlers            map[string]handler
 }
 
-func NewConsumer(config ConsumerConfig) messaging.Consumer {
+func NewConsumer(config *ConsumerConfig) (messaging.Consumer, error) {
+	if err := config.isValid(); err != nil {
+		return nil, err
+	}
+
+	config.setDefaults()
+
 	creds := credentials.NewStaticCredentials(config.AccessKey, config.SecretKey, "")
 
-	sess := session.Must(session.NewSession(&aws.Config{
+	sess, err := session.NewSession(&aws.Config{
 		Region:      aws.String(config.Region),
 		Credentials: creds,
-	}))
+	})
 
-	if config.VisibilityTimeout == 0 {
-		config.VisibilityTimeout = 20
-	}
-
-	if config.WaitTimeSeconds == 0 {
-		config.WaitTimeSeconds = 20
-	}
-
-	if config.MaxNumberOfMessages == 0 {
-		config.MaxNumberOfMessages = 5
+	if err != nil {
+		return nil, err
 	}
 
 	c := &consumer{
@@ -93,7 +127,17 @@ func NewConsumer(config ConsumerConfig) messaging.Consumer {
 		WaitTimeSeconds:     aws.Int64(c.config.WaitTimeSeconds),
 	}
 
-	return c
+	return c, nil
+}
+
+func MustNewConsumer(config *ConsumerConfig) messaging.Consumer {
+	consumer, err := NewConsumer(config)
+
+	if err != nil {
+		panic(err)
+	}
+
+	return consumer
 }
 
 func (c *consumer) getHandler(action string) (handler, bool) {
@@ -190,13 +234,16 @@ func (c *consumer) handleMessage(message *sqs.Message) {
 		return
 	}
 
+	log := logrus.WithFields(logrus.Fields{
+		"action":     sns.TopicArn,
+		"message_id": message.MessageId,
+		"body":       sns.Message,
+	})
+
 	handler, ok := c.getHandler(sns.TopicArn)
 
 	if !ok {
-		logrus.WithFields(logrus.Fields{
-			"error":  err,
-			"action": sns.TopicArn,
-		}).Error("Action not found.")
+		log.WithError(err).Error("Action not found.")
 		return
 	}
 
@@ -208,12 +255,7 @@ func (c *consumer) handleMessage(message *sqs.Message) {
 	}, handler.fn)
 
 	if err != nil {
-		logrus.WithFields(logrus.Fields{
-			"action":     handler.action,
-			"message_id": message.MessageId,
-			"body":       sns.Message,
-			"error":      err,
-		}).Debug("Failed to process event.")
+		log.WithError(err).Debug("Failed to process event.")
 		return
 	}
 
@@ -223,15 +265,11 @@ func (c *consumer) handleMessage(message *sqs.Message) {
 	})
 
 	if err != nil {
-		logrus.WithError(err).Error("Failed to delete message.")
+		log.WithError(err).Error("Failed to delete message.")
 		return
 	}
 
-	logrus.WithFields(logrus.Fields{
-		"action":     handler.action,
-		"body":       sns.Message,
-		"message_id": message.MessageId,
-	}).Debug("Message handled successfully.")
+	log.Debug("Message handled successfully.")
 }
 
 func (c *consumer) doConsume() {