refact pkg/acquisition: kinesis configuration

pkg/acquisition/modules/kinesis/config.go

@@ -31,38 +31,64 @@ type Configuration struct {
 	MaxRetries        int     `yaml:"max_retries"`
 }
 
-func (s *Source) UnmarshalConfig(yamlConfig []byte) error {
-	s.Config = Configuration{}
+func ConfigurationFromYAML(y []byte) (Configuration, error) {
+	var cfg Configuration
+
+	if err := yaml.UnmarshalWithOptions(y, &cfg, yaml.Strict()); err != nil {
+		return cfg, fmt.Errorf("cannot parse: %s", yaml.FormatError(err, false, false))
+	}
 
-	err := yaml.UnmarshalWithOptions(yamlConfig, &s.Config, yaml.Strict())
+	cfg.SetDefaults()
+	cfg.Normalize()
+
+	err := cfg.Validate()
 	if err != nil {
-		return fmt.Errorf("cannot parse kinesis datasource configuration: %s", yaml.FormatError(err, false, false))
+		return cfg, err
 	}
 
-	if s.Config.Mode == "" {
-		s.Config.Mode = configuration.TAIL_MODE
+	return cfg, nil
+}
+
+func (c *Configuration) SetDefaults() {
+	if c.Mode == "" {
+		c.Mode = configuration.TAIL_MODE
 	}
+}
 
-	if s.Config.StreamName == "" && !s.Config.UseEnhancedFanOut {
+func (c *Configuration) Normalize() {
+	if c.MaxRetries <= 0 {
+		c.MaxRetries = 10
+	}
+}
+
+func (s *Source) UnmarshalConfig(yamlConfig []byte) error {
+	cfg, err := ConfigurationFromYAML(yamlConfig)
+	if err != nil {
+		return err
+	}
+
+	s.Config = cfg
+
+	return nil
+}
+
+func (c *Configuration) Validate() error {
+	if c.StreamName == "" && !c.UseEnhancedFanOut {
 		return errors.New("stream_name is mandatory when use_enhanced_fanout is false")
 	}
 
-	if s.Config.StreamARN == "" && s.Config.UseEnhancedFanOut {
+	if c.StreamARN == "" && c.UseEnhancedFanOut {
 		return errors.New("stream_arn is mandatory when use_enhanced_fanout is true")
 	}
 
-	if s.Config.ConsumerName == "" && s.Config.UseEnhancedFanOut {
+	if c.ConsumerName == "" && c.UseEnhancedFanOut {
 		return errors.New("consumer_name is mandatory when use_enhanced_fanout is true")
 	}
 
-	if s.Config.StreamARN != "" && s.Config.StreamName != "" {
+	if c.StreamARN != "" && c.StreamName != "" {
 		return errors.New("stream_arn and stream_name are mutually exclusive")
 	}
 
-	if s.Config.MaxRetries <= 0 {
-		s.Config.MaxRetries = 10
-	}
-
 	return nil
 }