plugins/forwarder/grpc/nativecds/forwarder.go

// Licensed to Apache Software Foundation (ASF) under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Apache Software Foundation (ASF) licenses this file to you 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 nativecds

import (
	"context"
	"fmt"
	"reflect"

	v3 "skywalking.apache.org/repo/goapi/collect/agent/configuration/v3"

	"google.golang.org/grpc"

	v1 "skywalking.apache.org/repo/goapi/satellite/data/v1"

	"github.com/apache/skywalking-satellite/internal/pkg/config"
	"github.com/apache/skywalking-satellite/internal/satellite/event"
)

const (
	Name     = "native-cds-grpc-forwarder"
	ShowName = "Native CDS GRPC Forwarder"
)

type Forwarder struct {
	config.CommonFields

	cdsClient v3.ConfigurationDiscoveryServiceClient
}

func (f *Forwarder) Name() string {
	return Name
}

func (f *Forwarder) ShowName() string {
	return ShowName
}

func (f *Forwarder) Description() string {
	return "This is a synchronization grpc forwarder with the SkyWalking native Configuration Discovery Service protocol."
}

func (f *Forwarder) DefaultConfig() string {
	return ``
}

func (f *Forwarder) Prepare(connection interface{}) error {
	client, ok := connection.(*grpc.ClientConn)
	if !ok {
		return fmt.Errorf("the %s only accepts a grpc client, but received a %s",
			f.Name(), reflect.TypeOf(connection).String())
	}
	f.cdsClient = v3.NewConfigurationDiscoveryServiceClient(client)
	return nil
}

func (f *Forwarder) Forward(batch event.BatchEvents) error {
	return fmt.Errorf("the SkyWalking native Configuration Discovery Service protocol " +
		"is not support async forward")
}

func (f *Forwarder) ForwardType() v1.SniffType {
	return v1.SniffType_ConfigurationDiscoveryServiceType
}

func (f *Forwarder) SyncForward(e *v1.SniffData) (*v1.SniffData, grpc.ClientStream, error) {
	query := e.GetConfigurationSyncRequest()
	if query != nil {
		commands, err := f.cdsClient.FetchConfigurations(context.Background(), query)
		if err != nil {
			return nil, nil, err
		}
		return &v1.SniffData{Data: &v1.SniffData_Commands{Commands: commands}}, nil, nil
	}

	return nil, nil, fmt.Errorf("unsupport data")
}

func (f *Forwarder) SupportedSyncInvoke() bool {
	return true
}