This is a huge commit, it does following things:

1. refactor kubesphere dependency service client creation, we can
disable dependency by config
2. dependencies can be configured by configuration file
3. refactor cmd package using cobra.Command, so we can use hypersphere
to invoke command sepearately. Later we only need to build one image to
contains all kubesphere core components. One command to rule them all!
4. live reloading configuration currently not implemented

pkg/simple/client/redis/redis.go

@@ -18,48 +18,49 @@
 package redis
 
 import (
-	"flag"
-	"log"
-	"os"
-	"os/signal"
-	"sync"
-	"syscall"
-
+	"fmt"
 	"github.com/go-redis/redis"
+	"k8s.io/klog"
 )
 
-var (
-	redisHost       string
-	redisPassword   string
-	redisDB         int
-	redisClientOnce sync.Once
-	redisClient     *redis.Client
-)
-
-func init() {
-	flag.StringVar(&redisHost, "redis-server", "localhost:6379", "redis server host")
-	flag.StringVar(&redisPassword, "redis-password", "", "redis password")
-	flag.IntVar(&redisDB, "redis-db", 0, "redis db")
+type RedisClient struct {
+	client *redis.Client
 }
 
-func Client() *redis.Client {
+func NewRedisClientOrDie(options *RedisOptions, stopCh <-chan struct{}) *RedisClient {
+	client, err := NewRedisClient(options, stopCh)
+	if err != nil {
+		panic(err)
+	}
 
-	redisClientOnce.Do(func() {
-		redisClient = redis.NewClient(&redis.Options{
-			Addr:     redisHost,
-			Password: redisPassword,
-			DB:       redisDB,
-		})
-		if err := redisClient.Ping().Err(); err != nil {
-			log.Fatalln(err)
-		}
-		c := make(chan os.Signal, 0)
-		signal.Notify(c, os.Interrupt, syscall.SIGTERM)
-		go func() {
-			<-c
-			redisClient.Close()
-		}()
+	return client
+}
+
+func NewRedisClient(option *RedisOptions, stopCh <-chan struct{}) (*RedisClient, error) {
+	var r RedisClient
+
+	r.client = redis.NewClient(&redis.Options{
+		Addr:     fmt.Sprintf("%s:%d", option.Host, option.Port),
+		Password: option.Password,
+		DB:       option.DB,
 	})
 
-	return redisClient
+	if err := r.client.Ping().Err(); err != nil {
+		klog.Error("unable to reach redis host", err)
+		r.client.Close()
+		return nil, err
+	}
+
+	go func() {
+		<-stopCh
+		if err := r.client.Close(); err != nil {
+			klog.Error(err)
+		}
+	}()
+
+	return &r, nil
+}
+
+func (r *RedisClient) Redis() *redis.Client {
+	return r.client
 }