HDFS-WriterApp-Fixed all the code review comments

Fixed all the code review comments by Kiran

	1. Implemented a boolean channel instead of empty struct channel for signal, use WaitGroup
	to ensure all writers finish cleanup.
	2. Introduce JSON tags for configs
	4. remove all panic and fatalf code to ensure that the app doesnt crash anytime.
	5. remove unneccessary hdfsWriter null checks.
        6.remove the 'run' variable used in the infinite loop, replaced with 'return'

Issue-ID: ONAPARC-453
Change-Id: Ic77c59dc75a8898a3cf34999850e6687d40e7faa
Signed-off-by: Rajamohan Raj <rajamohan.raj@intel.com>

4 files changed, 19 insertions, 107 deletions

diff --git a/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/hdfs-config.go b/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/hdfs-config.go
deleted file mode 100644
index ac33bc6a..00000000
--- a/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/hdfs-config.go
+++ /dev/null
@@ -1,37 +0,0 @@
-package utils
-
-import (
-	"os"
-)
-
-// SetHdfsParametersByObjectMap set the value of the hdfs config parameters
-// and return HdfsConfig object
-func SetHdfsParametersByObjectMap(m map[string]interface{}) HdfsConfig{
-
-	hc := HdfsConfig{}
-	hc.hdfsURL = m["hdfs_url"].(string)
-	return hc
-
-}
-
-// SetHdfsParametersByEnvVariables sets the hdfs parameters
-func SetHdfsParametersByEnvVariables() HdfsConfig {
-	
-	slogger := GetLoggerInstance()
-	hdfsConfigObject := HdfsConfig{
-		hdfsURL: os.Getenv("HDFS_URL"),
-	}
-	slogger.Infof("::hdfsURL:: %s", hdfsConfigObject.hdfsURL)
-	return hdfsConfigObject
-	
-}
-
-// HdfsConfig contains hdfs related config items
-type HdfsConfig struct {
-	hdfsURL string
-}
-
-// GetHdfsURL returns HdfsURL
-func (h HdfsConfig) GetHdfsURL() string {
-	return h.hdfsURL
-}
\ No newline at end of file
diff --git a/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/hdfsUtils.go b/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/hdfsUtils.go
index 1a93a5ad..8edcec19 100644
--- a/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/hdfsUtils.go
+++ b/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/hdfsUtils.go
@@ -3,24 +3,9 @@ package utils
 import (
 	"fmt"
 	"github.com/colinmarc/hdfs"
-	//"sync"
-	//"go.uber.org/zap"
 )
 
 
-//var clientOnce sync.Once
-//var hdfsClient *hdfs.Client
-//var slogger *zap.SugaredLogger
-
-
-//GetHdfsClientInstance returns a singleton hdfsClient instance
-// func GetHdfsClientInstance(hdfsURL string) (*hdfs.Client){
-// 	clientOnce.Do(func(){
-// 		hdfsClient = createHdfsClient(hdfsURL)
-// 	})
-// 	return hdfsClient
-// }
-
 //CreateHdfsClient creates a hdfs client and returns hdfs client
 func CreateHdfsClient(hdfsURL string) (*hdfs.Client){
 	slogger := GetLoggerInstance()
diff --git a/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/kafka-config.go b/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/kafka-config.go
deleted file mode 100644
index 080bfd4b..00000000
--- a/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/kafka-config.go
+++ /dev/null
@@ -1,55 +0,0 @@
-package utils
-
-
-import (
-	"os"
-)
-
-// SetKafkaParametersByObjectMap sets the  value of the kafka parameters
-// and sets the KafkaConfig object 
-func SetKafkaParametersByObjectMap(m map[string]interface{}) KafkaConfig {
-	kc := KafkaConfig{}
-	kc.broker = m["broker"].(string)
-	kc.group = m["group"].(string)
-	kc.topic = m["topic"].(string)
-
-	return kc
-}
-
-// SetKafkaParametersByEnvVariables sets the kafka parameters
-func SetKafkaParametersByEnvVariables() KafkaConfig {
-	slogger := GetLoggerInstance()
-	
-	kafkaConfigObject := KafkaConfig{
-		broker: os.Getenv("BROKER"),
-		group: os.Getenv("GROUP"),
-		topic: os.Getenv("TOPIC"),
-	}
-	slogger.Infof("::broker:: %s", kafkaConfigObject.broker)
-	slogger.Infof("::group:: %s", kafkaConfigObject.group)
-	slogger.Infof("::topic:: %s", kafkaConfigObject.topic)
-
-	return kafkaConfigObject
-}
-
-// KafkaConfig contains all the config parameters needed for kafka. This can be extended over time
-type KafkaConfig struct {
-	broker string
-	group string
-	topic string
-}
-
-// GetBroker returns kafka broker configured
-func (k KafkaConfig) GetBroker() string {
-	return k.broker
-}
-
-// GetGroup returns kafka group configured
-func (k KafkaConfig) GetGroup() string {
-	return k.group
-}
-
-// GetTopic returns kafka topic configured
-func (k KafkaConfig) GetTopic() string {
-	return k.topic
-}
\ No newline at end of file
diff --git a/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/types.go b/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/types.go
new file mode 100644
index 00000000..3db3e420
--- /dev/null
+++ b/vnfs/DAaaS/microservices/GoApps/src/go-hdfs-writer/pkg/utils/types.go
@@ -0,0 +1,19 @@
+package utils
+
+// Pipeline type represents a stucture of a general pipeline
+type Pipeline struct{
+	KafkaConfiguration KafkaConfig `json:"kafkaConfig"`
+	HdfsConfiguration HdfsConfig `json:"hdfsConfig"`
+}
+
+// HdfsConfig type represents the config items of HDFS
+type HdfsConfig struct {
+	HdfsURL string `json:"hdfs_url"`
+}
+
+// KafkaConfig type represents the config items of Kafka
+type KafkaConfig struct {
+	Broker string `json:"broker"`
+	Group string `json:"group"`
+	Topic string `json:"topic"`
+}
\ No newline at end of file