Fix some issues with initialisation

selector/blacklist/black_list_selector.go

@@ -56,6 +56,17 @@ func (r *blackListSelector) run() {
 	}
 }
 
+func (r *blackListSelector) Init(opts ...selector.Option) error {
+	for _, o := range opts {
+		o(&r.so)
+	}
+	return nil
+}
+
+func (r *blackListSelector) Options() selector.Options {
+	return r.so
+}
+
 func (r *blackListSelector) Select(service string, opts ...selector.SelectOption) (selector.Next, error) {
 	var sopts selector.SelectOptions
 	for _, opt := range opts {

selector/random_selector.go

@@ -15,6 +15,17 @@ func init() {
 	rand.Seed(time.Now().Unix())
 }
 
+func (r *randomSelector) Init(opts ...Option) error {
+	for _, o := range opts {
+		o(&r.so)
+	}
+	return nil
+}
+
+func (r *randomSelector) Options() Options {
+	return r.so
+}
+
 func (r *randomSelector) Select(service string, opts ...SelectOption) (Next, error) {
 	var sopts SelectOptions
 	for _, opt := range opts {

selector/roundrobin/round_robin_selector.go

@@ -16,6 +16,17 @@ func init() {
 	cmd.DefaultSelectors["roundrobin"] = NewSelector
 }
 
+func (r *roundRobinSelector) Init(opts ...selector.Option) error {
+	for _, o := range opts {
+		o(&r.so)
+	}
+	return nil
+}
+
+func (r *roundRobinSelector) Options() selector.Options {
+	return r.so
+}
+
 func (r *roundRobinSelector) Select(service string, opts ...selector.SelectOption) (selector.Next, error) {
 	var sopts selector.SelectOptions
 	for _, opt := range opts {

selector/selector.go

@@ -64,6 +64,8 @@ import (
 // and mark their status. This allows host pools and other things
 // to be built using various algorithms.
 type Selector interface {
+	Init(opts ...Option) error
+	Options() Options
 	// Select returns a function which should return the next node
 	Select(service string, opts ...SelectOption) (Next, error)
 	// Mark sets the success/error against a node