feat: registry.

registry/eureka/client.go

@@ -1,28 +1,357 @@
 package eureka
 
 import (
-	eurekaKratos "github.com/go-kratos/kratos/contrib/registry/eureka/v2"
-	"github.com/go-kratos/kratos/v2/log"
-
-	conf "github.com/tx7do/kratos-bootstrap/api/gen/go/conf/v1"
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"math/rand"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
 )
 
-// NewRegistry 创建一个注册发现客户端 - Eureka
-func NewRegistry(c *conf.Registry) *eurekaKratos.Registry {
-	if c == nil || c.Eureka == nil {
+const (
+	statusUp           = "UP"
+	statusDown         = "DOWN"
+	statusOutOfService = "OUT_OF_SERVICE"
+	heartbeatRetry     = 3
+	maxIdleConns       = 100
+	heartbeatTime      = 10 * time.Second
+	httpTimeout        = 3 * time.Second
+	refreshTime        = 30 * time.Second
+)
+
+type Endpoint struct {
+	InstanceID     string
+	IP             string
+	AppID          string
+	Port           int
+	SecurePort     int
+	HomePageURL    string
+	StatusPageURL  string
+	HealthCheckURL string
+	MetaData       map[string]string
+}
+
+// ApplicationsRootResponse for /eureka/apps
+type ApplicationsRootResponse struct {
+	ApplicationsResponse `json:"applications"`
+}
+
+type ApplicationsResponse struct {
+	Version      string        `json:"versions__delta"`
+	AppsHashcode string        `json:"apps__hashcode"`
+	Applications []Application `json:"application"`
+}
+
+type Application struct {
+	Name     string     `json:"name"`
+	Instance []Instance `json:"instance"`
+}
+
+type RequestInstance struct {
+	Instance Instance `json:"instance"`
+}
+
+type Instance struct {
+	InstanceID     string            `json:"instanceId"`
+	HostName       string            `json:"hostName"`
+	Port           Port              `json:"port"`
+	App            string            `json:"app"`
+	IPAddr         string            `json:"ipAddr"`
+	VipAddress     string            `json:"vipAddress"`
+	Status         string            `json:"status"`
+	SecurePort     Port              `json:"securePort"`
+	HomePageURL    string            `json:"homePageUrl"`
+	StatusPageURL  string            `json:"statusPageUrl"`
+	HealthCheckURL string            `json:"healthCheckUrl"`
+	DataCenterInfo DataCenterInfo    `json:"dataCenterInfo"`
+	Metadata       map[string]string `json:"metadata"`
+}
+
+type Port struct {
+	Port    int    `json:"$"`
+	Enabled string `json:"@enabled"`
+}
+
+type DataCenterInfo struct {
+	Name  string `json:"name"`
+	Class string `json:"@class"`
+}
+
+var _ APIInterface = (*Client)(nil)
+
+type APIInterface interface {
+	Register(ctx context.Context, ep Endpoint) error
+	Deregister(ctx context.Context, appID, instanceID string) error
+	Heartbeat(ep Endpoint)
+	FetchApps(ctx context.Context) []Application
+	FetchAllUpInstances(ctx context.Context) []Instance
+	FetchAppInstances(ctx context.Context, appID string) (m Application, err error)
+	FetchAppUpInstances(ctx context.Context, appID string) []Instance
+	FetchAppInstance(ctx context.Context, appID string, instanceID string) (m Instance, err error)
+	FetchInstance(ctx context.Context, instanceID string) (m Instance, err error)
+	Out(ctx context.Context, appID, instanceID string) error
+	Down(ctx context.Context, appID, instanceID string) error
+}
+
+type ClientOption func(e *Client)
+
+func WithMaxRetry(maxRetry int) ClientOption {
+	return func(e *Client) { e.maxRetry = maxRetry }
+}
+
+func WithHeartbeatInterval(interval time.Duration) ClientOption {
+	return func(e *Client) {
+		e.heartbeatInterval = interval
+	}
+}
+
+func WithClientContext(ctx context.Context) ClientOption {
+	return func(e *Client) { e.ctx = ctx }
+}
+
+func WithNamespace(path string) ClientOption {
+	return func(e *Client) { e.eurekaPath = path }
+}
+
+type Client struct {
+	ctx               context.Context
+	urls              []string
+	eurekaPath        string
+	maxRetry          int
+	heartbeatInterval time.Duration
+	client            *http.Client
+	keepalive         map[string]chan struct{}
+	lock              sync.Mutex
+}
+
+func NewClient(urls []string, opts ...ClientOption) *Client {
+	tr := &http.Transport{
+		MaxIdleConns: maxIdleConns,
+	}
+
+	e := &Client{
+		ctx:               context.Background(),
+		urls:              urls,
+		eurekaPath:        "eureka/v2",
+		maxRetry:          len(urls),
+		heartbeatInterval: heartbeatTime,
+		client:            &http.Client{Transport: tr, Timeout: httpTimeout},
+		keepalive:         make(map[string]chan struct{}),
+	}
+
+	for _, o := range opts {
+		o(e)
+	}
+
+	return e
+}
+
+func (e *Client) FetchApps(ctx context.Context) []Application {
+	var m ApplicationsRootResponse
+	if err := e.do(ctx, http.MethodGet, []string{"apps"}, nil, &m); err != nil {
 		return nil
 	}
 
-	var opts []eurekaKratos.Option
-	opts = append(opts, eurekaKratos.WithHeartbeat(c.Eureka.HeartbeatInterval.AsDuration()))
-	opts = append(opts, eurekaKratos.WithRefresh(c.Eureka.RefreshInterval.AsDuration()))
-	opts = append(opts, eurekaKratos.WithEurekaPath(c.Eureka.Path))
+	return m.Applications
+}
 
-	var err error
-	var reg *eurekaKratos.Registry
-	if reg, err = eurekaKratos.New(c.Eureka.Endpoints, opts...); err != nil {
-		log.Fatal(err)
+func (e *Client) FetchAppInstances(ctx context.Context, appID string) (m Application, err error) {
+	err = e.do(ctx, http.MethodGet, []string{"apps", appID}, nil, &m)
+	return
+}
+
+func (e *Client) FetchAppUpInstances(ctx context.Context, appID string) []Instance {
+	app, err := e.FetchAppInstances(ctx, appID)
+	if err != nil {
+		return nil
+	}
+	return e.filterUp(app)
+}
+
+func (e *Client) FetchAppInstance(ctx context.Context, appID string, instanceID string) (m Instance, err error) {
+	err = e.do(ctx, http.MethodGet, []string{"apps", appID, instanceID}, nil, &m)
+	return
+}
+
+func (e *Client) FetchInstance(ctx context.Context, instanceID string) (m Instance, err error) {
+	err = e.do(ctx, http.MethodGet, []string{"instances", instanceID}, nil, &m)
+	return
+}
+
+func (e *Client) Out(ctx context.Context, appID, instanceID string) error {
+	return e.do(ctx, http.MethodPut, []string{"apps", appID, instanceID, fmt.Sprintf("status?value=%s", statusOutOfService)}, nil, nil)
+}
+
+func (e *Client) Down(ctx context.Context, appID, instanceID string) error {
+	return e.do(ctx, http.MethodPut, []string{"apps", appID, instanceID, fmt.Sprintf("status?value=%s", statusDown)}, nil, nil)
+}
+
+func (e *Client) FetchAllUpInstances(ctx context.Context) []Instance {
+	return e.filterUp(e.FetchApps(ctx)...)
+}
+
+func (e *Client) Register(ctx context.Context, ep Endpoint) error {
+	return e.registerEndpoint(ctx, ep)
+}
+
+func (e *Client) Deregister(ctx context.Context, appID, instanceID string) error {
+	if err := e.do(ctx, http.MethodDelete, []string{"apps", appID, instanceID}, nil, nil); err != nil {
+		return err
+	}
+	go e.cancelHeartbeat(appID)
+	return nil
+}
+
+func (e *Client) registerEndpoint(ctx context.Context, ep Endpoint) error {
+	instance := RequestInstance{
+		Instance: Instance{
+			InstanceID: ep.InstanceID,
+			HostName:   ep.AppID,
+			Port: Port{
+				Port:    ep.Port,
+				Enabled: "true",
+			},
+			App:        ep.AppID,
+			IPAddr:     ep.IP,
+			VipAddress: ep.AppID,
+			Status:     statusUp,
+			SecurePort: Port{
+				Port:    ep.SecurePort,
+				Enabled: "false",
+			},
+			HomePageURL:    ep.HomePageURL,
+			StatusPageURL:  ep.StatusPageURL,
+			HealthCheckURL: ep.HealthCheckURL,
+			DataCenterInfo: DataCenterInfo{
+				Name:  "MyOwn",
+				Class: "com.netflix.appinfo.InstanceInfo$DefaultDataCenterInfo",
+			},
+			Metadata: ep.MetaData,
+		},
 	}
 
-	return reg
+	body, err := json.Marshal(instance)
+	if err != nil {
+		return err
+	}
+	return e.do(ctx, http.MethodPost, []string{"apps", ep.AppID}, bytes.NewReader(body), nil)
+}
+
+func (e *Client) Heartbeat(ep Endpoint) {
+	e.lock.Lock()
+	e.keepalive[ep.AppID] = make(chan struct{})
+	e.lock.Unlock()
+
+	ticker := time.NewTicker(e.heartbeatInterval)
+	defer ticker.Stop()
+	retryCount := 0
+	for {
+		select {
+		case <-e.ctx.Done():
+			return
+		case <-e.keepalive[ep.AppID]:
+			return
+		case <-ticker.C:
+			if err := e.do(e.ctx, http.MethodPut, []string{"apps", ep.AppID, ep.InstanceID}, nil, nil); err != nil {
+				if retryCount++; retryCount > heartbeatRetry {
+					_ = e.registerEndpoint(e.ctx, ep)
+					retryCount = 0
+				}
+			}
+		}
+	}
+}
+
+func (e *Client) cancelHeartbeat(appID string) {
+	e.lock.Lock()
+	defer e.lock.Unlock()
+	if ch, ok := e.keepalive[appID]; ok {
+		ch <- struct{}{}
+	}
+}
+
+func (e *Client) filterUp(apps ...Application) (res []Instance) {
+	for _, app := range apps {
+		for _, ins := range app.Instance {
+			if ins.Status == statusUp {
+				res = append(res, ins)
+			}
+		}
+	}
+
+	return
+}
+
+func (e *Client) pickServer(currentTimes int) string {
+	return e.urls[currentTimes%e.maxRetry]
+}
+
+func (e *Client) shuffle() {
+	rand.Seed(time.Now().UnixNano())
+	rand.Shuffle(len(e.urls), func(i, j int) {
+		e.urls[i], e.urls[j] = e.urls[j], e.urls[i]
+	})
+}
+
+func (e *Client) buildAPI(currentTimes int, params ...string) string {
+	if currentTimes == 0 {
+		e.shuffle()
+	}
+	server := e.pickServer(currentTimes)
+	params = append([]string{server, e.eurekaPath}, params...)
+	return strings.Join(params, "/")
+}
+
+func (e *Client) request(ctx context.Context, method string, params []string, input io.Reader, output interface{}, i int) (bool, error) {
+	request, err := http.NewRequestWithContext(ctx, method, e.buildAPI(i, params...), input)
+	if err != nil {
+		return false, err
+	}
+	request.Header.Add("User-Agent", "go-eureka-client")
+	request.Header.Add("Accept", "application/json;charset=UTF-8")
+	request.Header.Add("Content-Type", "application/json;charset=UTF-8")
+	resp, err := e.client.Do(request)
+	if err != nil {
+		return true, err
+	}
+	defer func() {
+		_, _ = io.Copy(io.Discard, resp.Body)
+		_ = resp.Body.Close()
+	}()
+
+	if output != nil && resp.StatusCode/100 == 2 {
+		data, err := io.ReadAll(resp.Body)
+		if err != nil {
+			return false, err
+		}
+		err = json.Unmarshal(data, output)
+		if err != nil {
+			return false, err
+		}
+	}
+
+	if resp.StatusCode >= http.StatusBadRequest {
+		return false, fmt.Errorf("response Error %d", resp.StatusCode)
+	}
+
+	return false, nil
+}
+
+func (e *Client) do(ctx context.Context, method string, params []string, input io.Reader, output interface{}) error {
+	for i := 0; i < e.maxRetry; i++ {
+		retry, err := e.request(ctx, method, params, input, output, i)
+		if retry {
+			continue
+		}
+		if err != nil {
+			return err
+		}
+		return nil
+	}
+	return fmt.Errorf("retry after %d times", e.maxRetry)
 }

registry/eureka/client_creator.go

@@ -0,0 +1,33 @@
+package eureka
+
+import (
+	"github.com/go-kratos/kratos/v2/log"
+
+	conf "github.com/tx7do/kratos-bootstrap/api/gen/go/conf/v1"
+)
+
+// NewRegistry 创建一个注册发现客户端 - Eureka
+func NewRegistry(c *conf.Registry) *Registry {
+	if c == nil || c.Eureka == nil {
+		return nil
+	}
+
+	var opts []Option
+	if c.Eureka.HeartbeatInterval != nil {
+		opts = append(opts, WithHeartbeat(c.Eureka.HeartbeatInterval.AsDuration()))
+	}
+	if c.Eureka.RefreshInterval != nil {
+		opts = append(opts, WithRefresh(c.Eureka.RefreshInterval.AsDuration()))
+	}
+	if c.Eureka.Path != "" {
+		opts = append(opts, WithEurekaPath(c.Eureka.Path))
+	}
+
+	var err error
+	var reg *Registry
+	if reg, err = New(c.Eureka.Endpoints, opts...); err != nil {
+		log.Fatal(err)
+	}
+
+	return reg
+}

registry/eureka/eureka.go

@@ -0,0 +1,137 @@
+package eureka
+
+import (
+	"context"
+	"strings"
+	"sync"
+	"time"
+)
+
+type subscriber struct {
+	appID    string
+	callBack func()
+}
+
+type API struct {
+	cli             *Client
+	allInstances    map[string][]Instance
+	subscribers     map[string]*subscriber
+	refreshInterval time.Duration
+	lock            sync.Mutex
+}
+
+func NewAPI(ctx context.Context, client *Client, refreshInterval time.Duration) *API {
+	e := &API{
+		cli:             client,
+		allInstances:    make(map[string][]Instance),
+		subscribers:     make(map[string]*subscriber),
+		refreshInterval: refreshInterval,
+	}
+
+	// it is required to broadcast for the first time
+	go e.broadcast()
+
+	go e.refresh(ctx)
+
+	return e
+}
+
+func (e *API) refresh(ctx context.Context) {
+	ticker := time.NewTicker(e.refreshInterval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			e.broadcast()
+		}
+	}
+}
+
+func (e *API) broadcast() {
+	instances := e.cacheAllInstances()
+	if instances == nil {
+		return
+	}
+
+	for _, subscriber := range e.subscribers {
+		go subscriber.callBack()
+	}
+	defer e.lock.Unlock()
+	e.lock.Lock()
+	e.allInstances = instances
+}
+
+func (e *API) cacheAllInstances() map[string][]Instance {
+	items := make(map[string][]Instance)
+	instances := e.cli.FetchAllUpInstances(context.Background())
+	for _, instance := range instances {
+		items[e.ToAppID(instance.App)] = append(items[instance.App], instance)
+	}
+
+	return items
+}
+
+func (e *API) Register(ctx context.Context, serviceName string, endpoints ...Endpoint) error {
+	appID := e.ToAppID(serviceName)
+	upInstances := make(map[string]struct{})
+
+	for _, ins := range e.GetService(ctx, appID) {
+		upInstances[ins.InstanceID] = struct{}{}
+	}
+
+	for _, ep := range endpoints {
+		if _, ok := upInstances[ep.InstanceID]; !ok {
+			if err := e.cli.Register(ctx, ep); err != nil {
+				return err
+			}
+			go e.cli.Heartbeat(ep)
+		}
+	}
+
+	return nil
+}
+
+// Deregister ctx is the same as register ctx
+func (e *API) Deregister(ctx context.Context, endpoints []Endpoint) error {
+	for _, ep := range endpoints {
+		if err := e.cli.Deregister(ctx, ep.AppID, ep.InstanceID); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (e *API) Subscribe(serverName string, fn func()) error {
+	e.lock.Lock()
+	defer e.lock.Unlock()
+	appID := e.ToAppID(serverName)
+	e.subscribers[appID] = &subscriber{
+		appID:    appID,
+		callBack: fn,
+	}
+	go e.broadcast()
+	return nil
+}
+
+func (e *API) GetService(ctx context.Context, serverName string) []Instance {
+	appID := e.ToAppID(serverName)
+	if ins, ok := e.allInstances[appID]; ok {
+		return ins
+	}
+
+	// if not in allInstances of API, you can try to obtain it separately again
+	return e.cli.FetchAppUpInstances(ctx, appID)
+}
+
+func (e *API) Unsubscribe(serverName string) {
+	e.lock.Lock()
+	defer e.lock.Unlock()
+	delete(e.subscribers, e.ToAppID(serverName))
+}
+
+func (e *API) ToAppID(serverName string) string {
+	return strings.ToUpper(serverName)
+}

registry/eureka/go.mod

@@ -0,0 +1,29 @@
+module github.com/tx7do/kratos-bootstrap/registry/eureka
+
+go 1.24.0
+
+toolchain go1.24.3
+
+replace (
+	github.com/armon/go-metrics => github.com/hashicorp/go-metrics v0.4.1
+
+	github.com/tx7do/kratos-bootstrap/api => ../../api
+	github.com/tx7do/kratos-bootstrap/registry => ../registry
+)
+
+require (
+	github.com/go-kratos/kratos/v2 v2.8.4
+	github.com/stretchr/testify v1.10.0
+	github.com/tx7do/kratos-bootstrap/api v0.0.20
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
+	github.com/google/go-cmp v0.7.0 // indirect
+	github.com/kr/text v0.2.0 // indirect
+	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
+	github.com/rogpeppe/go-internal v1.13.1 // indirect
+	golang.org/x/sync v0.14.0 // indirect
+	google.golang.org/protobuf v1.36.6 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

registry/eureka/go.sum

@@ -0,0 +1,26 @@
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
+github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-kratos/kratos/v2 v2.8.4 h1:eIJLE9Qq9WSoKx+Buy2uPyrahtF/lPh+Xf4MTpxhmjs=
+github.com/go-kratos/kratos/v2 v2.8.4/go.mod h1:mq62W2101a5uYyRxe+7IdWubu7gZCGYqSNKwGFiiRcw=
+github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
+github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rogpeppe/go-internal v1.13.1 h1:KvO1DLK/DRN07sQ1LQKScxyZJuNnedQ5/wKSR38lUII=
+github.com/rogpeppe/go-internal v1.13.1/go.mod h1:uMEvuHeurkdAXX61udpOXGD/AzZDWNMNyH2VO9fmH0o=
+github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
+github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/sync v0.14.0 h1:woo0S4Yywslg6hp4eUFjTVOyKt0RookbpAHG4c1HmhQ=
+golang.org/x/sync v0.14.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
+google.golang.org/protobuf v1.36.6 h1:z1NpPI8ku2WgiWnf+t9wTPsn6eP1L7ksHUlkfLvd9xY=
+google.golang.org/protobuf v1.36.6/go.mod h1:jduwjTPXsFjZGTmRluh+L6NjiWu7pchiJ2/5YcXBHnY=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

registry/eureka/options.go

@@ -0,0 +1,25 @@
+package eureka
+
+import (
+	"context"
+	"time"
+)
+
+type Option func(o *Registry)
+
+// WithContext with registry context.
+func WithContext(ctx context.Context) Option {
+	return func(o *Registry) { o.ctx = ctx }
+}
+
+func WithHeartbeat(interval time.Duration) Option {
+	return func(o *Registry) { o.heartbeatInterval = interval }
+}
+
+func WithRefresh(interval time.Duration) Option {
+	return func(o *Registry) { o.refreshInterval = interval }
+}
+
+func WithEurekaPath(path string) Option {
+	return func(o *Registry) { o.eurekaPath = path }
+}

registry/eureka/register.go

@@ -0,0 +1,124 @@
+package eureka
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/go-kratos/kratos/v2/registry"
+)
+
+var (
+	_ registry.Registrar = (*Registry)(nil)
+	_ registry.Discovery = (*Registry)(nil)
+)
+
+type Registry struct {
+	ctx               context.Context
+	api               *API
+	heartbeatInterval time.Duration
+	refreshInterval   time.Duration
+	eurekaPath        string
+}
+
+func New(eurekaUrls []string, opts ...Option) (*Registry, error) {
+	r := &Registry{
+		ctx:               context.Background(),
+		heartbeatInterval: heartbeatTime,
+		refreshInterval:   refreshTime,
+		eurekaPath:        "eureka/v2",
+	}
+
+	for _, o := range opts {
+		o(r)
+	}
+
+	client := NewClient(eurekaUrls, WithHeartbeatInterval(r.heartbeatInterval), WithClientContext(r.ctx), WithNamespace(r.eurekaPath))
+	r.api = NewAPI(r.ctx, client, r.refreshInterval)
+	return r, nil
+}
+
+// Register 这里的Context是每个注册器独享的
+func (r *Registry) Register(ctx context.Context, service *registry.ServiceInstance) error {
+	return r.api.Register(ctx, service.Name, r.Endpoints(service)...)
+}
+
+// Deregister registry service to zookeeper.
+func (r *Registry) Deregister(ctx context.Context, service *registry.ServiceInstance) error {
+	return r.api.Deregister(ctx, r.Endpoints(service))
+}
+
+// GetService get services from zookeeper
+func (r *Registry) GetService(ctx context.Context, serviceName string) ([]*registry.ServiceInstance, error) {
+	instances := r.api.GetService(ctx, serviceName)
+	items := make([]*registry.ServiceInstance, 0, len(instances))
+	for _, instance := range instances {
+		items = append(items, &registry.ServiceInstance{
+			ID:        instance.Metadata["ID"],
+			Name:      instance.Metadata["Name"],
+			Version:   instance.Metadata["Version"],
+			Endpoints: []string{instance.Metadata["Endpoints"]},
+			Metadata:  instance.Metadata,
+		})
+	}
+
+	return items, nil
+}
+
+// Watch 是独立的ctx
+func (r *Registry) Watch(ctx context.Context, serviceName string) (registry.Watcher, error) {
+	return newWatch(ctx, r.api, serviceName)
+}
+
+func (r *Registry) Endpoints(service *registry.ServiceInstance) []Endpoint {
+	res := make([]Endpoint, 0, len(service.Endpoints))
+	for _, ep := range service.Endpoints {
+		start := strings.Index(ep, "//")
+		end := strings.LastIndex(ep, ":")
+		appID := strings.ToUpper(service.Name)
+		ip := ep[start+2 : end]
+		sport := ep[end+1:]
+		port, _ := strconv.Atoi(sport)
+		securePort := 443
+		homePageURL := fmt.Sprintf("%s/", ep)
+		statusPageURL := fmt.Sprintf("%s/info", ep)
+		healthCheckURL := fmt.Sprintf("%s/health", ep)
+		instanceID := strings.Join([]string{ip, appID, sport}, ":")
+		metadata := make(map[string]string)
+		if len(service.Metadata) > 0 {
+			metadata = service.Metadata
+		}
+		if s, ok := service.Metadata["securePort"]; ok {
+			securePort, _ = strconv.Atoi(s)
+		}
+		if s, ok := service.Metadata["homePageURL"]; ok {
+			homePageURL = s
+		}
+		if s, ok := service.Metadata["statusPageURL"]; ok {
+			statusPageURL = s
+		}
+		if s, ok := service.Metadata["healthCheckURL"]; ok {
+			healthCheckURL = s
+		}
+		metadata["ID"] = service.ID
+		metadata["Name"] = service.Name
+		metadata["Version"] = service.Version
+		metadata["Endpoints"] = ep
+		metadata["agent"] = "go-eureka-client"
+		res = append(res, Endpoint{
+			AppID:          appID,
+			IP:             ip,
+			Port:           port,
+			SecurePort:     securePort,
+			HomePageURL:    homePageURL,
+			StatusPageURL:  statusPageURL,
+			HealthCheckURL: healthCheckURL,
+			InstanceID:     instanceID,
+			MetaData:       metadata,
+		})
+	}
+
+	return res
+}

registry/eureka/register_test.go

@@ -0,0 +1,114 @@
+package eureka
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/go-kratos/kratos/v2/registry"
+)
+
+func TestRegistry(_ *testing.T) {
+	ctx := context.Background()
+	ctx, cancel := context.WithCancel(ctx)
+	s1 := &registry.ServiceInstance{
+		ID:        "0",
+		Name:      "helloworld",
+		Endpoints: []string{"http://127.0.0.1:1111"},
+	}
+	s2 := &registry.ServiceInstance{
+		ID:        "0",
+		Name:      "helloworld2",
+		Endpoints: []string{"http://127.0.0.1:222"},
+	}
+
+	r, _ := New([]string{"https://127.0.0.1:18761"}, WithContext(ctx), WithHeartbeat(time.Second), WithRefresh(time.Second), WithEurekaPath("eureka"))
+
+	go do(r, s1)
+	go do(r, s2)
+
+	time.Sleep(time.Second * 20)
+	cancel()
+	time.Sleep(time.Second * 1)
+}
+
+func do(r *Registry, s *registry.ServiceInstance) {
+	w, err := r.Watch(context.Background(), s.Name)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer func() {
+		_ = w.Stop()
+	}()
+	go func() {
+		for {
+			res, nextErr := w.Next()
+			if nextErr != nil {
+				return
+			}
+			log.Printf("watch: %d", len(res))
+			for _, r := range res {
+				log.Printf("next: %+v", r)
+			}
+		}
+	}()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	if err = r.Register(ctx, s); err != nil {
+		log.Fatal(err)
+	}
+
+	time.Sleep(time.Second * 10)
+	res, err := r.GetService(ctx, s.Name)
+	if err != nil {
+		log.Fatal(err)
+	}
+	for i, re := range res {
+		log.Printf("first %d re:%v\n", i, re)
+	}
+
+	if len(res) != 1 && res[0].Name != s.Name {
+		log.Fatalf("not expected: %+v", res)
+	}
+
+	if err = r.Deregister(ctx, s); err != nil {
+		log.Fatal(err)
+	}
+	cancel()
+	time.Sleep(time.Second * 10)
+
+	res, err = r.GetService(ctx, s.Name)
+	if err != nil {
+		log.Fatal(err)
+	}
+	for i, re := range res {
+		log.Printf("second %d re:%v\n", i, re)
+	}
+	if len(res) != 0 {
+		log.Fatalf("not expected empty")
+	}
+}
+
+func TestLock(_ *testing.T) {
+	type me struct {
+		lock sync.Mutex
+	}
+
+	a := &me{}
+	go func() {
+		defer a.lock.Unlock()
+		a.lock.Lock()
+		fmt.Println("This is fmt first.")
+		time.Sleep(time.Second * 5)
+	}()
+	go func() {
+		defer a.lock.Unlock()
+		a.lock.Lock()
+		fmt.Println("This is fmt second.")
+		time.Sleep(time.Second * 5)
+	}()
+	time.Sleep(time.Second * 10)
+}

registry/eureka/watcher.go

@@ -0,0 +1,60 @@
+package eureka
+
+import (
+	"context"
+
+	"github.com/go-kratos/kratos/v2/registry"
+)
+
+var _ registry.Watcher = (*watcher)(nil)
+
+type watcher struct {
+	ctx        context.Context
+	cancel     context.CancelFunc
+	cli        *API
+	watchChan  chan struct{}
+	serverName string
+}
+
+func newWatch(ctx context.Context, cli *API, serverName string) (*watcher, error) {
+	w := &watcher{
+		ctx:        ctx,
+		cli:        cli,
+		serverName: serverName,
+		watchChan:  make(chan struct{}, 1),
+	}
+	w.ctx, w.cancel = context.WithCancel(ctx)
+	e := w.cli.Subscribe(
+		serverName,
+		func() {
+			w.watchChan <- struct{}{}
+		},
+	)
+	return w, e
+}
+
+func (w *watcher) Next() (services []*registry.ServiceInstance, err error) {
+	select {
+	case <-w.ctx.Done():
+		return nil, w.ctx.Err()
+	case <-w.watchChan:
+		instances := w.cli.GetService(w.ctx, w.serverName)
+		services = make([]*registry.ServiceInstance, 0, len(instances))
+		for _, instance := range instances {
+			services = append(services, &registry.ServiceInstance{
+				ID:        instance.Metadata["ID"],
+				Name:      instance.Metadata["Name"],
+				Version:   instance.Metadata["Version"],
+				Endpoints: []string{instance.Metadata["Endpoints"]},
+				Metadata:  instance.Metadata,
+			})
+		}
+		return
+	}
+}
+
+func (w *watcher) Stop() error {
+	w.cancel()
+	w.cli.Unsubscribe(w.serverName)
+	return nil
+}