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/devops/options.go

@@ -0,0 +1,81 @@
+package devops
+
+import (
+	"fmt"
+	"github.com/spf13/pflag"
+)
+
+type DevopsOptions struct {
+	Host           string `json:",omitempty" yaml:",omitempty" description:"Jenkins service host address"`
+	Username       string `json:",omitempty" yaml:",omitempty" description:"Jenkins admin username"`
+	Password       string `json:",omitempty" yaml:",omitempty" description:"Jenkins admin password"`
+	MaxConnections int    `json:"maxConnections,omitempty" yaml:"maxConnections,omitempty" description:"Maximum connections allowed to connect to Jenkins"`
+}
+
+// NewDevopsOptions returns a `zero` instance
+func NewDevopsOptions() *DevopsOptions {
+	return &DevopsOptions{
+		Host:           "",
+		Username:       "",
+		Password:       "",
+		MaxConnections: 100,
+	}
+}
+
+func (s *DevopsOptions) ApplyTo(options *DevopsOptions) {
+	if options == nil {
+		return
+	}
+
+	if s.Host != "" {
+		options.Host = s.Host
+	}
+
+	if s.Username != "" {
+		options.Username = s.Username
+	}
+
+	if s.Password != "" {
+		options.Password = s.Password
+	}
+
+	if s.MaxConnections > 0 {
+		options.MaxConnections = s.MaxConnections
+	}
+}
+
+//
+func (s *DevopsOptions) Validate() []error {
+	errors := []error{}
+
+	// devops is not needed, ignore rest options
+	if s.Host == "" {
+		return errors
+	}
+
+	if s.Username == "" || s.Password == "" {
+		errors = append(errors, fmt.Errorf("jenkins's username or password is empty"))
+	}
+
+	if s.MaxConnections <= 0 {
+		errors = append(errors, fmt.Errorf("jenkins's maximum connections should be greater than 0"))
+	}
+
+	return errors
+}
+
+func (s *DevopsOptions) AddFlags(fs *pflag.FlagSet) {
+	fs.StringVar(&s.Host, "jenkins-host", s.Host, ""+
+		"Jenkins service host address. If left blank, means Jenkins "+
+		"is unnecessary.")
+
+	fs.StringVar(&s.Username, "jenkins-username", s.Username, ""+
+		"Username for access to Jenkins service. Leave it blank if there isn't any.")
+
+	fs.StringVar(&s.Password, "jenkins-password", s.Password, ""+
+		"Password for access to Jenkins service, used pair with username.")
+
+	fs.IntVar(&s.MaxConnections, "jenkins-max-connections", s.MaxConnections, ""+
+		"Maximum allowed connections to Jenkins. ")
+
+}