add web api

pkg/registry/bypass.go

@@ -30,19 +30,28 @@ func (r *bypassRegistry) Unregister(name string) {
 	r.m.Delete(name)
 }
 
+func (r *bypassRegistry) IsRegistered(name string) bool {
+	_, ok := r.m.Load(name)
+	return ok
+}
+
 func (r *bypassRegistry) Get(name string) bypass.Bypass {
-	if _, ok := r.m.Load(name); !ok {
-		return nil
-	}
 	return &bypassWrapper{name: name}
 }
 
+func (r *bypassRegistry) get(name string) bypass.Bypass {
+	if v, ok := r.m.Load(name); ok {
+		return v.(bypass.Bypass)
+	}
+	return nil
+}
+
 type bypassWrapper struct {
 	name string
 }
 
 func (w *bypassWrapper) Contains(addr string) bool {
-	bp := bypassReg.Get(w.name)
+	bp := bypassReg.get(w.name)
 	if bp == nil {
 		return false
 	}

pkg/registry/chain.go

@@ -30,19 +30,28 @@ func (r *chainRegistry) Unregister(name string) {
 	r.m.Delete(name)
 }
 
+func (r *chainRegistry) IsRegistered(name string) bool {
+	_, ok := r.m.Load(name)
+	return ok
+}
+
 func (r *chainRegistry) Get(name string) chain.Chainer {
-	if _, ok := r.m.Load(name); !ok {
-		return nil
-	}
 	return &chainWrapper{name: name}
 }
 
+func (r *chainRegistry) get(name string) chain.Chainer {
+	if v, ok := r.m.Load(name); ok {
+		return v.(chain.Chainer)
+	}
+	return nil
+}
+
 type chainWrapper struct {
 	name string
 }
 
 func (w *chainWrapper) Route(network, address string) *chain.Route {
-	v := Chain().Get(w.name)
+	v := Chain().get(w.name)
 	if v == nil {
 		return nil
 	}

pkg/registry/hosts.go

@@ -31,19 +31,28 @@ func (r *hostsRegistry) Unregister(name string) {
 	r.m.Delete(name)
 }
 
+func (r *hostsRegistry) IsRegistered(name string) bool {
+	_, ok := r.m.Load(name)
+	return ok
+}
+
 func (r *hostsRegistry) Get(name string) hosts.HostMapper {
-	if _, ok := r.m.Load(name); !ok {
-		return nil
-	}
 	return &hostsWrapper{name: name}
 }
 
+func (r *hostsRegistry) get(name string) hosts.HostMapper {
+	if v, ok := r.m.Load(name); ok {
+		return v.(hosts.HostMapper)
+	}
+	return nil
+}
+
 type hostsWrapper struct {
 	name string
 }
 
 func (w *hostsWrapper) Lookup(network, host string) ([]net.IP, bool) {
-	v := Hosts().Get(w.name)
+	v := Hosts().get(w.name)
 	if v == nil {
 		return nil, false
 	}

pkg/registry/registry.go

@@ -11,8 +11,7 @@ import (
 )
 
 var (
-	ErrDup      = errors.New("registry: duplicate instance")
-	ErrNotFound = errors.New("registry: instance not found")
+	ErrDup = errors.New("registry: duplicate instance")
 )
 
 type NewListener func(opts ...listener.Option) listener.Listener

pkg/registry/resolver.go

@@ -32,21 +32,30 @@ func (r *resolverRegistry) Unregister(name string) {
 	r.m.Delete(name)
 }
 
+func (r *resolverRegistry) IsRegistered(name string) bool {
+	_, ok := r.m.Load(name)
+	return ok
+}
+
 func (r *resolverRegistry) Get(name string) resolver.Resolver {
-	if _, ok := r.m.Load(name); !ok {
-		return nil
-	}
 	return &resolverWrapper{name: name}
 }
 
+func (r *resolverRegistry) get(name string) resolver.Resolver {
+	if v, ok := r.m.Load(name); ok {
+		return v.(resolver.Resolver)
+	}
+	return nil
+}
+
 type resolverWrapper struct {
 	name string
 }
 
 func (w *resolverWrapper) Resolve(ctx context.Context, network, host string) ([]net.IP, error) {
-	r := Resolver().Get(w.name)
+	r := Resolver().get(w.name)
 	if r == nil {
-		return nil, ErrNotFound
+		return nil, resolver.ErrInvalid
 	}
 	return r.Resolve(ctx, network, host)
 }

pkg/registry/service.go

@@ -30,6 +30,11 @@ func (r *serviceRegistry) Unregister(name string) {
 	r.m.Delete(name)
 }
 
+func (r *serviceRegistry) IsRegistered(name string) bool {
+	_, ok := r.m.Load(name)
+	return ok
+}
+
 func (r *serviceRegistry) Get(name string) *service.Service {
 	v, ok := r.m.Load(name)
 	if !ok {