feat: added configuration center function (#3035)

Co-authored-by: aiden.ma <Aiden.ma@yijinin.com>

core/configcenter/configurator.go

@@ -0,0 +1,205 @@
+package configurator
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"strings"
+	"sync"
+	"sync/atomic"
+
+	"github.com/zeromicro/go-zero/core/configcenter/subscriber"
+	"github.com/zeromicro/go-zero/core/logx"
+	"github.com/zeromicro/go-zero/core/mapping"
+	"github.com/zeromicro/go-zero/core/threading"
+)
+
+var (
+	errorEmptyConfig         = errors.New("empty config value")
+	errorMissUnmarshalerType = errors.New("miss unmarshaler type")
+)
+
+// Configurator is the interface for configuration center.
+type Configurator[T any] interface {
+	// GetConfig returns the subscription value.
+	GetConfig() (T, error)
+	// AddListener adds a listener to the subscriber.
+	AddListener(listener func())
+}
+
+type (
+	// Config is the configuration for Configurator.
+	Config struct {
+		// Type is the value type, yaml, json or toml.
+		Type string `json:",default=yaml,options=[yaml,json,toml]"`
+		// Log indicates whether to log the configuration.
+		Log bool `json:",default=ture"`
+	}
+
+	configCenter[T any] struct {
+		conf        Config
+		unmarshaler LoaderFn
+
+		subscriber subscriber.Subscriber
+
+		listeners []func()
+		lock      sync.Mutex
+		snapshot  atomic.Value
+	}
+
+	value[T any] struct {
+		data        string
+		marshalData T
+		err         error
+	}
+)
+
+// Configurator is the interface for configuration center.
+var _ Configurator[any] = (*configCenter[any])(nil)
+
+// MustNewConfigCenter returns a Configurator, exits on errors.
+func MustNewConfigCenter[T any](c Config, subscriber subscriber.Subscriber) Configurator[T] {
+	cc, err := NewConfigCenter[T](c, subscriber)
+	logx.Must(err)
+
+	return cc
+}
+
+// NewConfigCenter returns a Configurator.
+func NewConfigCenter[T any](c Config, subscriber subscriber.Subscriber) (Configurator[T], error) {
+	unmarshaler, ok := Unmarshaler(strings.ToLower(c.Type))
+	if !ok {
+		return nil, fmt.Errorf("unknown format: %s", c.Type)
+	}
+
+	cc := &configCenter[T]{
+		conf:        c,
+		unmarshaler: unmarshaler,
+		subscriber:  subscriber,
+		listeners:   nil,
+		lock:        sync.Mutex{},
+		snapshot:    atomic.Value{},
+	}
+
+	if err := cc.loadConfig(); err != nil {
+		return nil, err
+	}
+
+	if err := cc.subscriber.AddListener(cc.onChange); err != nil {
+		return nil, err
+	}
+
+	if _, err := cc.GetConfig(); err != nil {
+		return nil, err
+	}
+
+	return cc, nil
+}
+
+// AddListener adds listener to s.
+func (c *configCenter[T]) AddListener(listener func()) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	c.listeners = append(c.listeners, listener)
+}
+
+// GetConfig return structured config.
+func (c *configCenter[T]) GetConfig() (T, error) {
+	var r T
+	v := c.value()
+	if v == nil || len(v.data) < 1 {
+		return r, errorEmptyConfig
+	}
+
+	return v.marshalData, v.err
+}
+
+// Value returns the subscription value.
+func (c *configCenter[T]) Value() string {
+	v := c.value()
+	if v == nil {
+		return ""
+	}
+	return v.data
+}
+
+func (c *configCenter[T]) loadConfig() error {
+	v, err := c.subscriber.Value()
+	if err != nil {
+		if c.conf.Log {
+			logx.Errorf("ConfigCenter loads changed configuration, error: %v", err)
+		}
+		return err
+	}
+
+	if c.conf.Log {
+		logx.Infof("ConfigCenter loads changed configuration, content [%s]", v)
+	}
+
+	c.snapshot.Store(c.genValue(v))
+	return nil
+}
+
+func (c *configCenter[T]) onChange() {
+	_ = c.loadConfig()
+
+	c.lock.Lock()
+	listeners := make([]func(), len(c.listeners))
+	copy(listeners, c.listeners)
+	c.lock.Unlock()
+
+	for _, l := range listeners {
+		threading.GoSafe(l)
+	}
+}
+
+func (c *configCenter[T]) value() *value[T] {
+	content := c.snapshot.Load()
+	if content == nil {
+		return nil
+	}
+	return content.(*value[T])
+}
+
+func (c *configCenter[T]) genValue(data string) *value[T] {
+	v := &value[T]{
+		data: data,
+	}
+	if len(data) <= 0 {
+		return v
+	}
+
+	t := reflect.TypeOf(v.marshalData)
+	// if the type is nil, it means that the user has not set the type of the configuration.
+	if t == nil {
+		v.err = errorMissUnmarshalerType
+		return v
+	}
+
+	t = mapping.Deref(t)
+
+	switch t.Kind() {
+	case reflect.Struct, reflect.Array, reflect.Slice:
+		err := c.unmarshaler([]byte(data), &v.marshalData)
+		if err != nil {
+			v.err = err
+			if c.conf.Log {
+				logx.Errorf("ConfigCenter unmarshal configuration failed, err: %+v, content [%s]", err.Error(), data)
+			}
+		}
+	case reflect.String:
+		if str, ok := any(data).(T); ok {
+			v.marshalData = str
+		} else {
+			v.err = errorMissUnmarshalerType
+		}
+	default:
+		if c.conf.Log {
+			logx.Errorf("ConfigCenter unmarshal configuration missing unmarshaler for type: %s, content [%s]",
+				t.Kind(), data)
+		}
+		v.err = errorMissUnmarshalerType
+	}
+
+	return v
+}

core/configcenter/configurator_test.go

@@ -0,0 +1,233 @@
+package configurator
+
+import (
+	"errors"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewConfigCenter(t *testing.T) {
+	_, err := NewConfigCenter[any](Config{
+		Log: true,
+	}, &mockSubscriber{})
+	assert.Error(t, err)
+
+	_, err = NewConfigCenter[any](Config{
+		Type: "json",
+		Log:  true,
+	}, &mockSubscriber{})
+	assert.Error(t, err)
+}
+
+func TestConfigCenter_GetConfig(t *testing.T) {
+	mock := &mockSubscriber{}
+	type Data struct {
+		Name string `json:"name"`
+	}
+
+	mock.v = `{"name": "go-zero"}`
+	c1, err := NewConfigCenter[Data](Config{
+		Type: "json",
+		Log:  true,
+	}, mock)
+	assert.NoError(t, err)
+
+	data, err := c1.GetConfig()
+	assert.NoError(t, err)
+	assert.Equal(t, "go-zero", data.Name)
+
+	mock.v = `{"name": "111"}`
+	c2, err := NewConfigCenter[Data](Config{Type: "json"}, mock)
+	assert.NoError(t, err)
+
+	mock.v = `{}`
+	c3, err := NewConfigCenter[string](Config{
+		Type: "json",
+		Log:  true,
+	}, mock)
+	assert.NoError(t, err)
+	_, err = c3.GetConfig()
+	assert.NoError(t, err)
+
+	data, err = c2.GetConfig()
+	assert.NoError(t, err)
+
+	mock.lisErr = errors.New("mock error")
+	_, err = NewConfigCenter[Data](Config{
+		Type: "json",
+		Log:  true,
+	}, mock)
+	assert.Error(t, err)
+}
+
+func TestConfigCenter_onChange(t *testing.T) {
+	mock := &mockSubscriber{}
+	type Data struct {
+		Name string `json:"name"`
+	}
+
+	mock.v = `{"name": "go-zero"}`
+	c1, err := NewConfigCenter[Data](Config{Type: "json", Log: true}, mock)
+	assert.NoError(t, err)
+
+	data, err := c1.GetConfig()
+	assert.NoError(t, err)
+	assert.Equal(t, "go-zero", data.Name)
+
+	mock.v = `{"name": "go-zero2"}`
+	mock.change()
+
+	data, err = c1.GetConfig()
+	assert.NoError(t, err)
+	assert.Equal(t, "go-zero2", data.Name)
+
+	mock.valErr = errors.New("mock error")
+	_, err = NewConfigCenter[Data](Config{Type: "json", Log: false}, mock)
+	assert.Error(t, err)
+}
+
+func TestConfigCenter_Value(t *testing.T) {
+	mock := &mockSubscriber{}
+	mock.v = "1234"
+
+	c, err := NewConfigCenter[string](Config{
+		Type: "json",
+		Log:  true,
+	}, mock)
+	assert.NoError(t, err)
+
+	cc := c.(*configCenter[string])
+
+	assert.Equal(t, cc.Value(), "1234")
+
+	mock.valErr = errors.New("mock error")
+
+	_, err = NewConfigCenter[any](Config{
+		Type: "json",
+		Log:  true,
+	}, mock)
+	assert.Error(t, err)
+}
+
+func TestConfigCenter_AddListener(t *testing.T) {
+	mock := &mockSubscriber{}
+	mock.v = "1234"
+	c, err := NewConfigCenter[string](Config{
+		Type: "json",
+		Log:  true,
+	}, mock)
+	assert.NoError(t, err)
+
+	cc := c.(*configCenter[string])
+	var a, b int
+	var mutex sync.Mutex
+	cc.AddListener(func() {
+		mutex.Lock()
+		a = 1
+		mutex.Unlock()
+	})
+	cc.AddListener(func() {
+		mutex.Lock()
+		b = 2
+		mutex.Unlock()
+	})
+
+	assert.Equal(t, 2, len(cc.listeners))
+
+	mock.change()
+
+	time.Sleep(time.Millisecond * 100)
+
+	mutex.Lock()
+	assert.Equal(t, 1, a)
+	assert.Equal(t, 2, b)
+	mutex.Unlock()
+}
+
+func TestConfigCenter_genValue(t *testing.T) {
+	t.Run("data is empty", func(t *testing.T) {
+		c := &configCenter[string]{
+			unmarshaler: defaultRegistry.unmarshalers["json"],
+			conf:        Config{Log: true},
+		}
+		v := c.genValue("")
+		assert.Equal(t, "", v.data)
+	})
+
+	t.Run("invalid template type", func(t *testing.T) {
+		c := &configCenter[any]{
+			unmarshaler: defaultRegistry.unmarshalers["json"],
+			conf:        Config{Log: true},
+		}
+		v := c.genValue("xxxx")
+		assert.Equal(t, errorMissUnmarshalerType, v.err)
+	})
+
+	t.Run("unsupported template type", func(t *testing.T) {
+		c := &configCenter[int]{
+			unmarshaler: defaultRegistry.unmarshalers["json"],
+			conf:        Config{Log: true},
+		}
+		v := c.genValue("1")
+		assert.Equal(t, errorMissUnmarshalerType, v.err)
+	})
+
+	t.Run("supported template string type", func(t *testing.T) {
+		c := &configCenter[string]{
+			unmarshaler: defaultRegistry.unmarshalers["json"],
+			conf:        Config{Log: true},
+		}
+		v := c.genValue("12345")
+		assert.NoError(t, v.err)
+		assert.Equal(t, "12345", v.data)
+	})
+
+	t.Run("unmarshal fail", func(t *testing.T) {
+		c := &configCenter[struct {
+			Name string `json:"name"`
+		}]{
+			unmarshaler: defaultRegistry.unmarshalers["json"],
+			conf:        Config{Log: true},
+		}
+		v := c.genValue(`{"name":"new name}`)
+		assert.Equal(t, `{"name":"new name}`, v.data)
+		assert.Error(t, v.err)
+	})
+
+	t.Run("success", func(t *testing.T) {
+		c := &configCenter[struct {
+			Name string `json:"name"`
+		}]{
+			unmarshaler: defaultRegistry.unmarshalers["json"],
+			conf:        Config{Log: true},
+		}
+		v := c.genValue(`{"name":"new name"}`)
+		assert.Equal(t, `{"name":"new name"}`, v.data)
+		assert.Equal(t, "new name", v.marshalData.Name)
+		assert.NoError(t, v.err)
+	})
+}
+
+type mockSubscriber struct {
+	v              string
+	lisErr, valErr error
+	listener       func()
+}
+
+func (m *mockSubscriber) AddListener(listener func()) error {
+	m.listener = listener
+	return m.lisErr
+}
+
+func (m *mockSubscriber) Value() (string, error) {
+	return m.v, m.valErr
+}
+
+func (m *mockSubscriber) change() {
+	if m.listener != nil {
+		m.listener()
+	}
+}

core/configcenter/subscriber/etcd.go

@@ -0,0 +1,60 @@
+package subscriber
+
+import (
+	"github.com/zeromicro/go-zero/core/discov"
+	"github.com/zeromicro/go-zero/core/logx"
+)
+
+type (
+	// etcdSubscriber is a subscriber that subscribes to etcd.
+	etcdSubscriber struct {
+		*discov.Subscriber
+	}
+
+	// EtcdConf is the configuration for etcd.
+	EtcdConf discov.EtcdConf
+)
+
+// MustNewEtcdSubscriber returns an etcd Subscriber, exits on errors.
+func MustNewEtcdSubscriber(conf EtcdConf) Subscriber {
+	s, err := NewEtcdSubscriber(conf)
+	logx.Must(err)
+
+	return s
+}
+
+// NewEtcdSubscriber returns an etcd Subscriber.
+func NewEtcdSubscriber(conf EtcdConf) (Subscriber, error) {
+	var opts = []discov.SubOption{
+		discov.WithDisablePrefix(),
+	}
+	if len(conf.User) != 0 {
+		opts = append(opts, discov.WithSubEtcdAccount(conf.User, conf.Pass))
+	}
+	if len(conf.CertFile) != 0 || len(conf.CertKeyFile) != 0 || len(conf.CACertFile) != 0 {
+		opts = append(opts,
+			discov.WithSubEtcdTLS(conf.CertFile, conf.CertKeyFile, conf.CACertFile, conf.InsecureSkipVerify))
+	}
+
+	s, err := discov.NewSubscriber(conf.Hosts, conf.Key, opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	return &etcdSubscriber{Subscriber: s}, nil
+}
+
+// AddListener adds a listener to the subscriber.
+func (s *etcdSubscriber) AddListener(listener func()) error {
+	s.Subscriber.AddListener(listener)
+	return nil
+}
+
+// Value returns the value of the subscriber.
+func (s *etcdSubscriber) Value() (string, error) {
+	vs := s.Subscriber.Values()
+	if len(vs) != 0 {
+		return vs[len(vs)-1], nil
+	}
+	return "", nil
+}

core/configcenter/subscriber/subscriber.go

@@ -0,0 +1,9 @@
+package subscriber
+
+// Subscriber is the interface for configcenter subscribers.
+type Subscriber interface {
+	// AddListener adds a listener to the subscriber.
+	AddListener(listener func()) error
+	// Value returns the value of the subscriber.
+	Value() (string, error)
+}

core/configcenter/unmarshaler.go

@@ -0,0 +1,46 @@
+package configurator
+
+import (
+	"sync"
+
+	"github.com/zeromicro/go-zero/core/conf"
+)
+
+type (
+	// unmarshalerRegistry is the registry for unmarshalers.
+	unmarshalerRegistry struct {
+		unmarshalers map[string]LoaderFn
+
+		mu sync.RWMutex
+	}
+
+	// LoaderFn is the function type for loading configuration.
+	LoaderFn func([]byte, any) error
+)
+
+var defaultRegistry *unmarshalerRegistry
+
+func init() {
+	defaultRegistry = &unmarshalerRegistry{
+		unmarshalers: map[string]LoaderFn{
+			"json": conf.LoadFromJsonBytes,
+			"toml": conf.LoadFromTomlBytes,
+			"yaml": conf.LoadFromYamlBytes,
+		},
+	}
+}
+
+// RegisterUnmarshaler registers an unmarshaler.
+func RegisterUnmarshaler(name string, fn LoaderFn) {
+	defaultRegistry.mu.Lock()
+	defaultRegistry.unmarshalers[name] = fn
+	defaultRegistry.mu.Unlock()
+}
+
+// Unmarshaler returns the unmarshaler by name.
+func Unmarshaler(name string) (LoaderFn, bool) {
+	defaultRegistry.mu.RLock()
+	fn, ok := defaultRegistry.unmarshalers[name]
+	defaultRegistry.mu.RUnlock()
+	return fn, ok
+}

core/configcenter/unmarshaler_test.go

@@ -0,0 +1,28 @@
+package configurator
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRegisterUnmarshaler(t *testing.T) {
+	RegisterUnmarshaler("test", func(data []byte, v interface{}) error {
+		return nil
+	})
+
+	_, ok := Unmarshaler("test")
+	assert.True(t, ok)
+
+	_, ok = Unmarshaler("test2")
+	assert.False(t, ok)
+
+	_, ok = Unmarshaler("json")
+	assert.True(t, ok)
+
+	_, ok = Unmarshaler("toml")
+	assert.True(t, ok)
+
+	_, ok = Unmarshaler("yaml")
+	assert.True(t, ok)
+}

core/discov/internal/registry.go

@@ -10,13 +10,14 @@ import (
 	"sync"
 	"time"
 
+	"go.etcd.io/etcd/api/v3/v3rpc/rpctypes"
+	clientv3 "go.etcd.io/etcd/client/v3"
+
 	"github.com/zeromicro/go-zero/core/contextx"
 	"github.com/zeromicro/go-zero/core/lang"
 	"github.com/zeromicro/go-zero/core/logx"
 	"github.com/zeromicro/go-zero/core/syncx"
 	"github.com/zeromicro/go-zero/core/threading"
-	"go.etcd.io/etcd/api/v3/v3rpc/rpctypes"
-	clientv3 "go.etcd.io/etcd/client/v3"
 )
 
 var (
@@ -45,7 +46,7 @@ func (r *Registry) GetConn(endpoints []string) (EtcdClient, error) {
 }
 
 // Monitor monitors the key on given etcd endpoints, notify with the given UpdateListener.
-func (r *Registry) Monitor(endpoints []string, key string, l UpdateListener) error {
+func (r *Registry) Monitor(endpoints []string, key string, l UpdateListener, disablePrefix bool) error {
 	c, exists := r.getCluster(endpoints)
 	// if exists, the existing values should be updated to the listener.
 	if exists {
@@ -55,7 +56,7 @@ func (r *Registry) Monitor(endpoints []string, key string, l UpdateListener) err
 		}
 	}
 
-	return c.monitor(key, l)
+	return c.monitor(key, l, disablePrefix)
 }
 
 func (r *Registry) getCluster(endpoints []string) (c *cluster, exists bool) {
@@ -86,6 +87,7 @@ type cluster struct {
 	watchGroup    *threading.RoutineGroup
 	done          chan lang.PlaceholderType
 	lock          sync.RWMutex
+	disablePrefix bool
 }
 
 func newCluster(endpoints []string) *cluster {
@@ -224,7 +226,12 @@ func (c *cluster) load(cli EtcdClient, key string) int64 {
 	for {
 		var err error
 		ctx, cancel := context.WithTimeout(c.context(cli), RequestTimeout)
+		if c.disablePrefix {
+			resp, err = cli.Get(ctx, key)
+		} else {
 			resp, err = cli.Get(ctx, makeKeyPrefix(key), clientv3.WithPrefix())
+		}
+
 		cancel()
 		if err == nil {
 			break
@@ -247,9 +254,10 @@ func (c *cluster) load(cli EtcdClient, key string) int64 {
 	return resp.Header.Revision
 }
 
-func (c *cluster) monitor(key string, l UpdateListener) error {
+func (c *cluster) monitor(key string, l UpdateListener, disablePrefix bool) error {
 	c.lock.Lock()
 	c.listeners[key] = append(c.listeners[key], l)
+	c.disablePrefix = disablePrefix
 	c.lock.Unlock()
 
 	cli, err := c.getClient()
@@ -315,14 +323,20 @@ func (c *cluster) watch(cli EtcdClient, key string, rev int64) {
 }
 
 func (c *cluster) watchStream(cli EtcdClient, key string, rev int64) error {
-	var rch clientv3.WatchChan
-	if rev != 0 {
-		rch = cli.Watch(clientv3.WithRequireLeader(c.context(cli)), makeKeyPrefix(key),
-			clientv3.WithPrefix(), clientv3.WithRev(rev+1))
-	} else {
-		rch = cli.Watch(clientv3.WithRequireLeader(c.context(cli)), makeKeyPrefix(key),
-			clientv3.WithPrefix())
+	var (
+		rch      clientv3.WatchChan
+		ops      []clientv3.OpOption
+		watchKey = key
+	)
+	if !c.disablePrefix {
+		watchKey = makeKeyPrefix(key)
+		ops = append(ops, clientv3.WithPrefix())
 	}
+	if rev != 0 {
+		ops = append(ops, clientv3.WithRev(rev+1))
+	}
+
+	rch = cli.Watch(clientv3.WithRequireLeader(c.context(cli)), watchKey, ops...)
 
 	for {
 		select {

core/discov/internal/registry_test.go

@@ -289,7 +289,7 @@ func TestRegistry_Monitor(t *testing.T) {
 		},
 	}
 	GetRegistry().lock.Unlock()
-	assert.Error(t, GetRegistry().Monitor(endpoints, "foo", new(mockListener)))
+	assert.Error(t, GetRegistry().Monitor(endpoints, "foo", new(mockListener), false))
 }
 
 type mockListener struct {

core/discov/subscriber.go

@@ -17,6 +17,7 @@ type (
 	Subscriber struct {
 		endpoints     []string
 		exclusive     bool
+		disablePrefix bool
 		items         *container
 	}
 )
@@ -34,7 +35,7 @@ func NewSubscriber(endpoints []string, key string, opts ...SubOption) (*Subscrib
 	}
 	sub.items = newContainer(sub.exclusive)
 
-	if err := internal.GetRegistry().Monitor(endpoints, key, sub.items); err != nil {
+	if err := internal.GetRegistry().Monitor(endpoints, key, sub.items, sub.disablePrefix); err != nil {
 		return nil, err
 	}
 
@@ -59,6 +60,13 @@ func Exclusive() SubOption {
 	}
 }
 
+// WithDisablePrefix turn off querying using key prefixes.
+func WithDisablePrefix() SubOption {
+	return func(sub *Subscriber) {
+		sub.disablePrefix = true
+	}
+}
+
 // WithSubEtcdAccount provides the etcd username/password.
 func WithSubEtcdAccount(user, pass string) SubOption {
 	return func(sub *Subscriber) {