Merge pull request #1161 from Patrick0308/feature/3.0-service-discovery

Imp: remote service discovery

.asf.yaml

@@ -1,5 +1,5 @@
-notifications:
-    commits:      commits@dubbo.apache.org
-    issues:       notifications@dubbo.apache.org
-    pullrequests: notifications@dubbo.apache.org
-    jira_options: link label link label
+notifications:
+    commits:      commits@dubbo.apache.org
+    issues:       notifications@dubbo.apache.org
+    pullrequests: notifications@dubbo.apache.org
+    jira_options: link label link label

.github/ISSUE_TEMPLATE/bug-report.md

@@ -1,19 +1,19 @@
----
-name: Bug Report
-about: Report a bug
-labels: kind/bug
-
----
-
-<!-- Please use this template while reporting a bug and provide as much info as possible. Not doing so may result in your bug not being addressed in a timely manner. Thanks!
-
--->
-
-
-**What happened**:
-
-**What you expected to happen**:
-
-**How to reproduce it (as minimally and precisely as possible)**:
-
-**Anything else we need to know?**:
+---
+name: Bug Report
+about: Report a bug
+labels: kind/bug
+
+---
+
+<!-- Please use this template while reporting a bug and provide as much info as possible. Not doing so may result in your bug not being addressed in a timely manner. Thanks!
+
+-->
+
+
+**What happened**:
+
+**What you expected to happen**:
+
+**How to reproduce it (as minimally and precisely as possible)**:
+
+**Anything else we need to know?**:

.github/ISSUE_TEMPLATE/enhancement.md

@@ -1,11 +1,11 @@
----
-name: Enhancement Request
-about: Suggest an enhancement
-labels: kind/feature
-
----
-<!-- Please only use this template for submitting enhancement requests -->
-
-**What would you like to be added**:
-
+---
+name: Enhancement Request
+about: Suggest an enhancement
+labels: kind/feature
+
+---
+<!-- Please only use this template for submitting enhancement requests -->
+
+**What would you like to be added**:
+
 **Why is this needed**:

common/constant/key.go

@@ -313,11 +313,12 @@ const (
 const (
 	SUBSCRIBED_SERVICE_NAMES_KEY               = "subscribed-services"
 	PROVIDER_BY                                = "provided-by"
-	EXPORTED_SERVICES_REVISION_PROPERTY_NAME   = "dubbo.exported-services.revision"
+	EXPORTED_SERVICES_REVISION_PROPERTY_NAME   = "dubbo.metadata.revision"
 	SUBSCRIBED_SERVICES_REVISION_PROPERTY_NAME = "dubbo.subscribed-services.revision"
 	SERVICE_INSTANCE_SELECTOR                  = "service-instance-selector"
 	METADATA_STORAGE_TYPE_PROPERTY_NAME        = "dubbo.metadata.storage-type"
 	DEFAULT_METADATA_STORAGE_TYPE              = "local"
+	REMOTE_METADATA_STORAGE_TYPE               = "remote"
 	SERVICE_INSTANCE_ENDPOINTS                 = "dubbo.endpoints"
 	METADATA_SERVICE_PREFIX                    = "dubbo.metadata-service."
 	METADATA_SERVICE_URL_PARAMS_PROPERTY_NAME  = METADATA_SERVICE_PREFIX + "url-params"

common/extension/metadata_remote.go

@@ -0,0 +1,33 @@
+package extension
+
+import (
+	"fmt"
+)
+
+import (
+	perrors "github.com/pkg/errors"
+)
+
+import (
+	"github.com/apache/dubbo-go/metadata/service/remote"
+)
+
+type remoteMetadataServiceCreator func() (remote.RemoteMetadataService, error)
+
+var (
+	creator remoteMetadataServiceCreator
+)
+
+// SetRemoteMetadataService will store the remote metadata service
+func SetRemoteMetadataService(creatorFunc remoteMetadataServiceCreator) {
+	creator = creatorFunc
+}
+
+// GetRemoteMetadataServiceFactory will create a MetadataService instance
+func GetRemoteMetadataService() (remote.RemoteMetadataService, error) {
+	if creator != nil {
+		return creator()
+	}
+	return nil, perrors.New(fmt.Sprintf("could not find the metadata service creator for metadataType: remote, please check whether you have imported relative packages, \n" +
+		"remote - github.com/apache/dubbo-go/metadata/remote/impl"))
+}

common/extension/metadata_service.go

@@ -26,42 +26,29 @@ import (
 )
 
 import (
-	"github.com/apache/dubbo-go/common/logger"
+	"github.com/apache/dubbo-go/common/constant"
 	"github.com/apache/dubbo-go/metadata/service"
 )
 
+type localMetadataServiceCreator func() (service.MetadataService, error)
+
 var (
-	// there will be two types: local or remote
-	metadataServiceInsMap = make(map[string]func() (service.MetadataService, error), 2)
-	// remoteMetadataService
-	remoteMetadataService service.MetadataService
+	localMetadataServiceInsMap = make(map[string]localMetadataServiceCreator, 2)
 )
 
-// SetMetadataService will store the msType => creator pair
-func SetMetadataService(msType string, creator func() (service.MetadataService, error)) {
-	metadataServiceInsMap[msType] = creator
-}
-
-// GetMetadataService will create a MetadataService instance
-func GetMetadataService(msType string) (service.MetadataService, error) {
-	if creator, ok := metadataServiceInsMap[msType]; ok {
-		return creator()
-	}
-	return nil, perrors.New(fmt.Sprintf("could not find the metadata service creator for metadataType: %s, please check whether you have imported relative packages, \n"+
-		"local - github.com/apache/dubbo-go/metadata/service/inmemory, \n"+
-		"remote - github.com/apache/dubbo-go/metadata/service/remote", msType))
+// SetLocalMetadataService will store the msType => creator pair
+func SetLocalMetadataService(key string, creator localMetadataServiceCreator) {
+	localMetadataServiceInsMap[key] = creator
 }
 
-// GetRemoteMetadataService will get a RemoteMetadataService instance
-func GetRemoteMetadataService() (service.MetadataService, error) {
-	if remoteMetadataService != nil {
-		return remoteMetadataService, nil
+// GetMetadataService will create a inmemory MetadataService instance
+func GetLocalMetadataService(key string) (service.MetadataService, error) {
+	if key == "" {
+		key = constant.DEFAULT_KEY
 	}
-	if creator, ok := metadataServiceInsMap["remote"]; ok {
-		var err error
-		remoteMetadataService, err = creator()
-		return remoteMetadataService, err
+	if creator, ok := localMetadataServiceInsMap[key]; ok {
+		return creator()
 	}
-	logger.Warn("could not find the metadata service creator for metadataType: remote")
-	return nil, perrors.New(fmt.Sprintf("could not find the metadata service creator for metadataType: remote"))
+	return nil, perrors.New(fmt.Sprintf("could not find the metadata service creator for metadataType: local, please check whether you have imported relative packages, \n" +
+		"local - github.com/apache/dubbo-go/metadata/service/inmemory, "))
 }

common/extension/metadata_service_proxy_factory.go

@@ -22,6 +22,7 @@ import (
 )
 
 import (
+	"github.com/apache/dubbo-go/common/constant"
 	"github.com/apache/dubbo-go/metadata/service"
 )
 
@@ -37,10 +38,12 @@ func SetMetadataServiceProxyFactory(name string, creator MetadataServiceProxyFac
 // GetMetadataServiceProxyFactory will create an instance.
 // it will panic if the factory with name not found
 func GetMetadataServiceProxyFactory(name string) service.MetadataServiceProxyFactory {
+	if name == "" {
+		name = constant.DEFAULT_KEY
+	}
 	if f, ok := metadataServiceProxyFactoryMap[name]; ok {
 		return f()
 	}
 	panic(fmt.Sprintf("could not find the metadata service factory creator for name: %s, please check whether you have imported relative packages, \n"+
-		"local - github.com/apache/dubbo-go/metadata/service/inmemory, \n"+
-		"remote - github.com/apache/dubbo-go/metadata/service/remote", name))
+		"local - github.com/apache/dubbo-go/metadata/service/inmemory, \n", name))
 }