聊聊dubbo-go-proxy的ConsulRegistryLoad

序

本文主要研究一下dubbo-go-proxy的ConsulRegistryLoad

Loader

dubbo-go-proxy/pkg/registry/load.go

// Loader this interface defined for load services from different kinds registry, such as nacos,consul,zookeeper.
type Loader interface {
	// LoadAllServices load all services registered in registry
	LoadAllServices() ([]*common.URL, error)
	// GetCluster get the registry name
	GetCluster() (string, error)
}

Loader接口定義了LoadAllServices、GetCluster方法

ConsulRegistryLoad

dubbo-go-proxy/pkg/registry/consul.go

func init() {
	var _ Loader = new(ConsulRegistryLoad)
}

const (
	dubboAPIFilter = "dubbo in Tags"
)

// ConsulRegistryLoad load dubbo apis from consul registry
type ConsulRegistryLoad struct {
	Address string
	// Consul client.
	client  *consul.Client
	cluster string
}

func newConsulRegistryLoad(address, cluster string) (Loader, error) {
	config := &consul.Config{Address: address}
	client, err := consul.NewClient(config)
	if err != nil {
		return nil, err
	}

	r := &ConsulRegistryLoad{
		Address: address,
		client:  client,
		cluster: cluster,
	}

	return r, nil
}

ConsulRegistryLoad定義了Address、client、cluster屬性；newConsulRegistryLoad方法根據address及cluster來創建ConsulRegistryLoad

GetCluster

dubbo-go-proxy/pkg/registry/consul.go

func (crl *ConsulRegistryLoad) GetCluster() (string, error) {
	return crl.cluster, nil
}

GetCluster方法返回ConsulRegistryLoad的cluster屬性

LoadAllServices

dubbo-go-proxy/pkg/registry/consul.go

func (crl *ConsulRegistryLoad) LoadAllServices() ([]*common.URL, error) {
	agentServices, err := crl.client.Agent().ServicesWithFilter(dubboAPIFilter)
	if err != nil {
		logger.Error("consul load all apis error:%v", err)
		return nil, perrors.Wrap(err, "consul load all apis")
	}
	var urls []*common.URL
	for _, service := range agentServices {
		url, err := crl.transfer2Url(*service)
		if err != nil {
			logger.Warnf("consul transfer service to url error:%v", err)
			continue
		}
		urls = append(urls, url)
	}
	return urls, nil
}

LoadAllServices方法通過ConsulRegistryLoad的client.Agent().ServicesWithFilter來獲取agentServices，之後遍歷agentServices通過transfer2Url方法轉換爲url

transfer2Url

dubbo-go-proxy/pkg/registry/consul.go

func (crl *ConsulRegistryLoad) transfer2Url(service consul.AgentService) (*common.URL, error) {
	var params = url.Values{}
	var protocol string

	for _, tag := range service.Tags {
		kv := strings.Split(tag, "=")
		if len(kv) != 2 {
			continue
		}
		params.Add(kv[0], kv[1])
	}

	if url, ok := service.Meta["url"]; ok {
		protocol = strings.Split(url, ":")[0]
	}

	methodsParam := strings.Split(params.Get(constant.METHODS_KEY), ",")
	var methods = make([]string, len(methodsParam))
	for _, method := range methodsParam {
		if method != "" {
			methods = append(methods, method)
		}
	}
	url := common.NewURLWithOptions(common.WithPort(strconv.Itoa(service.Port)),
		common.WithProtocol(protocol), common.WithMethods(methods),
		common.WithIp(service.Address), common.WithParams(params))

	return url, nil
}

transfer2Url方法遍歷service.Tags追加到params，之後解析service.Meta["url"]，再解析params.Get(constant.METHODS_KEY)，最後通過common.NewURLWithOptions構建url

小結

ConsulRegistryLoad定義了Address、client、cluster屬性；newConsulRegistryLoad方法根據address及cluster來創建ConsulRegistryLoad；它實現了Loader接口，提供了GetCluster、LoadAllServices方法。

doc

• dubbo-go-proxy