Add Apollo data-source extension (#444)

* feat(pkg/datasource):add apollo datasource
* fix(pkg/datasource):fix ci problem
* feat(.github/workflow):add apollo datasource ci test command
* feat(datasource/apollo):change go.mod version to 1.13

Author: Casper-Mars

.github/workflows/go.yml

@@ -63,6 +63,8 @@ jobs:
         go test -race -count=1 ./... -coverprofile=coverage.txt -covermode=atomic
         cd ../nacos
         go test -race -count=1 ./... -coverprofile=coverage.txt -covermode=atomic
+        cd ../apollo
+        go test -race -count=1 ./... -coverprofile=coverage.txt -covermode=atomic
         cd ../../adapters/echo
         go test -race -count=1 ./... -coverprofile=coverage.txt -covermode=atomic
         cd ../gear

pkg/datasource/apollo/apollo.go

@@ -0,0 +1,103 @@
+package apollo
+
+import (
+	"github.com/alibaba/sentinel-golang/ext/datasource"
+	"github.com/apolloconfig/agollo/v4"
+	"github.com/apolloconfig/agollo/v4/component/log"
+	"github.com/apolloconfig/agollo/v4/env/config"
+	"github.com/pkg/errors"
+)
+
+var (
+	ErrEmptyKey   = errors.New("property key is empty")
+	ErrMissConfig = errors.New("miss config")
+)
+
+type Option func(o *options)
+
+type options struct {
+	handlers []datasource.PropertyHandler
+	logger   log.LoggerInterface
+	client   *agollo.Client
+}
+
+// WithPropertyHandlers set property handlers
+func WithPropertyHandlers(handlers ...datasource.PropertyHandler) Option {
+	return func(o *options) {
+		o.handlers = handlers
+	}
+}
+
+// WithLogger set apollo logger
+func WithLogger(logger log.LoggerInterface) Option {
+	return func(o *options) {
+		o.logger = logger
+	}
+}
+
+// apolloDatasource implements datasource.Datasource
+type apolloDatasource struct {
+	datasource.Base
+	client      *agollo.Client
+	propertyKey string
+}
+
+// NewDatasource create apollo datasource
+func NewDatasource(conf *config.AppConfig, propertyKey string, opts ...Option) (datasource.DataSource, error) {
+	if conf == nil {
+		return nil, ErrMissConfig
+	}
+	if propertyKey == "" {
+		return nil, ErrEmptyKey
+	}
+	option := &options{
+		logger: &log.DefaultLogger{},
+	}
+	for _, opt := range opts {
+		opt(option)
+	}
+	agollo.SetLogger(option.logger)
+	apolloClient, err := agollo.StartWithConfig(func() (*config.AppConfig, error) {
+		return conf, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	ds := &apolloDatasource{
+		client:      apolloClient,
+		propertyKey: propertyKey,
+	}
+	for _, handler := range option.handlers {
+		ds.AddPropertyHandler(handler)
+	}
+	return ds, nil
+}
+
+func (a *apolloDatasource) ReadSource() ([]byte, error) {
+	value := a.client.GetValue(a.propertyKey)
+	return []byte(value), nil
+}
+
+func (a *apolloDatasource) Initialize() error {
+	source, err := a.ReadSource()
+	if err != nil {
+		return err
+	}
+	a.handle(source)
+	listener := &customChangeListener{
+		ds: a,
+	}
+	a.client.AddChangeListener(listener)
+	return nil
+}
+
+func (a *apolloDatasource) Close() error {
+	return nil
+}
+
+func (a *apolloDatasource) handle(source []byte) {
+	err := a.Handle(source)
+	if err != nil {
+		log.Errorf("update config err: %s", err.Error())
+	}
+}

pkg/datasource/apollo/apollo_test.go

@@ -0,0 +1,63 @@
+package apollo
+
+import (
+	"testing"
+
+	"github.com/apolloconfig/agollo/v4/env/config"
+	"github.com/stretchr/testify/assert"
+)
+
+// must run an apollo server before test
+// this would be failed for CICD test. so it's disabled for now
+//func TestConfig(t *testing.T) {
+//
+//	var resultConfig string
+//
+//	propertyHandler := datasource2.NewDefaultPropertyHandler(
+//		func(src []byte) (interface{}, error) {
+//			return string(src), nil
+//		},
+//		func(data interface{}) error {
+//			s := data.(string)
+//			fmt.Println(s)
+//			resultConfig = s
+//			return nil
+//		},
+//	)
+//	c := &config.AppConfig{
+//		AppID:          "SampleApp",
+//		Cluster:        "DEV",
+//		IP:             "http://localhost:8080",
+//		NamespaceName:  "application",
+//		IsBackupConfig: true,
+//		Secret:         "1dc9532d02cd47f0bb26ee39d614ef8d",
+//	}
+//	datasource, err := NewDatasource(
+//		c, "timeout",
+//		WithLogger(&log.DefaultLogger{}),
+//		WithPropertyHandlers(propertyHandler),
+//	)
+//	assert.Nil(t, err)
+//	err = datasource.Initialize()
+//	assert.Nil(t, err)
+//	assert.Equal(t, "123", resultConfig)
+//	select {}
+//}
+
+func TestEmptyKey(t *testing.T) {
+	c := &config.AppConfig{
+		AppID:          "SampleApp",
+		Cluster:        "DEV",
+		IP:             "http://localhost:8080",
+		NamespaceName:  "application",
+		IsBackupConfig: true,
+		Secret:         "1dc9532d02cd47f0bb26ee39d614ef8d",
+	}
+	_, err := NewDatasource(c, "")
+	assert.Equal(t, ErrEmptyKey, err)
+}
+
+func TestMissConfig(t *testing.T) {
+	_, err := NewDatasource(nil, "test")
+	assert.Equal(t, ErrMissConfig, err)
+}

pkg/datasource/apollo/go.mod

@@ -0,0 +1,19 @@
+module github.com/alibaba/sentinel-golang/pkg/datasource/apollo
+
+go 1.13
+
+replace github.com/alibaba/sentinel-golang => ../../../
+
+require (
+	github.com/alibaba/sentinel-golang v1.0.3
+	github.com/apolloconfig/agollo/v4 v4.0.9
+	github.com/pkg/errors v0.9.1
+	github.com/stretchr/testify v1.7.0
+)
+
+require (
+	github.com/spf13/viper v1.9.0 // indirect
+	golang.org/x/sys v0.0.0-20211117180635-dee7805ff2e1 // indirect
+	golang.org/x/text v0.3.7 // indirect
+	gopkg.in/ini.v1 v1.64.0 // indirect
+)