refactor registry & add direct service discovery through staticIP or DNS (#261)

registry/direct/watcher.go

@@ -0,0 +1,164 @@
+// Copyright (c) 2022 Alibaba Group Holding Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package direct
+
+import (
+	"net"
+	"regexp"
+	"strconv"
+	"strings"
+	"sync"
+
+	"istio.io/api/networking/v1alpha3"
+	"istio.io/istio/pkg/config/protocol"
+	"istio.io/pkg/log"
+
+	apiv1 "github.com/alibaba/higress/api/networking/v1"
+	"github.com/alibaba/higress/pkg/common"
+	"github.com/alibaba/higress/registry"
+	provider "github.com/alibaba/higress/registry"
+	"github.com/alibaba/higress/registry/memory"
+)
+
+type watcher struct {
+	provider.BaseWatcher
+	apiv1.RegistryConfig
+	cache memory.Cache
+	mutex sync.Mutex
+}
+
+type WatcherOption func(w *watcher)
+
+func NewWatcher(cache memory.Cache, opts ...WatcherOption) (provider.Watcher, error) {
+	w := &watcher{
+		cache: cache,
+	}
+	for _, opt := range opts {
+		opt(w)
+	}
+	return w, nil
+}
+
+func WithType(t string) WatcherOption {
+	return func(w *watcher) {
+		w.Type = t
+	}
+}
+
+func WithName(name string) WatcherOption {
+	return func(w *watcher) {
+		w.Name = name
+	}
+}
+
+func WithDomain(domain string) WatcherOption {
+	return func(w *watcher) {
+		w.Domain = domain
+	}
+}
+
+func WithPort(port uint32) WatcherOption {
+	return func(w *watcher) {
+		w.Port = port
+	}
+}
+
+func (w *watcher) Run() {
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+	host := strings.Join([]string{w.Name, w.Type}, common.DotSeparator)
+	serviceEntry := w.generateServiceEntry(host)
+	if serviceEntry != nil {
+		w.cache.UpdateServiceEntryWrapper(host, &memory.ServiceEntryWrapper{
+			ServiceName:  w.Name,
+			ServiceEntry: serviceEntry,
+			Suffix:       w.Type,
+			RegistryType: w.Type,
+		})
+		w.UpdateService()
+	}
+	w.Ready(true)
+}
+
+func (w *watcher) Stop() {
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+	host := strings.Join([]string{w.Name, w.Type}, common.DotSeparator)
+	w.cache.DeleteServiceEntryWrapper(host)
+	w.Ready(false)
+}
+
+var domainRegex = regexp.MustCompile(`^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,6}$`)
+
+func (w *watcher) generateServiceEntry(host string) *v1alpha3.ServiceEntry {
+	endpoints := make([]*v1alpha3.WorkloadEntry, 0)
+	for _, ep := range strings.Split(w.Domain, common.CommaSeparator) {
+		var endpoint *v1alpha3.WorkloadEntry
+		if w.Type == string(registry.Static) {
+			pair := strings.Split(ep, common.ColonSeparator)
+			if len(pair) != 2 {
+				log.Errorf("invalid endpoint:%s with static type", ep)
+				return nil
+			}
+			port, err := strconv.ParseUint(pair[1], 10, 32)
+			if err != nil {
+				log.Errorf("invalid port:%s of endpoint:%s", pair[1], ep)
+				return nil
+			}
+			if net.ParseIP(pair[0]) == nil {
+				log.Errorf("invalid ip:%s of endpoint:%s", pair[0], ep)
+				return nil
+			}
+			endpoint = &v1alpha3.WorkloadEntry{
+				Address: pair[0],
+				Ports:   map[string]uint32{"http": uint32(port)},
+			}
+		} else if w.Type == string(registry.DNS) {
+			if !domainRegex.MatchString(ep) {
+				log.Errorf("invalid domain format:%s", ep)
+				return nil
+			}
+			endpoint = &v1alpha3.WorkloadEntry{
+				Address: ep,
+			}
+		} else {
+			log.Errorf("unknown direct service type:%s", w.Type)
+			return nil
+		}
+		endpoints = append(endpoints, endpoint)
+	}
+	if len(endpoints) == 0 {
+		log.Errorf("empty endpoints will not be pushed, host:%s", host)
+		return nil
+	}
+	var ports []*v1alpha3.Port
+	ports = append(ports, &v1alpha3.Port{
+		Number:   w.Port,
+		Name:     "http",
+		Protocol: string(protocol.HTTP),
+	})
+	se := &v1alpha3.ServiceEntry{
+		Hosts:     []string{host},
+		Ports:     ports,
+		Location:  v1alpha3.ServiceEntry_MESH_INTERNAL,
+		Endpoints: endpoints,
+	}
+	if w.Type == string(registry.Static) {
+		se.Resolution = v1alpha3.ServiceEntry_STATIC
+	} else if w.Type == string(registry.DNS) {
+		se.Resolution = v1alpha3.ServiceEntry_DNS
+	}
+	return se
+}