Tag Router

How to use

Prerequisites

• Docker and Docker Compose environment to deploy Nacos registry.
• Nacos Version 2.x+
• Go 1.23+

Run Nacos

Follow this instruction to install and start Nacos server.

Tag router

The tag router enables traffic control based on tags. The following is the example code.

Server side:

ins, err := dubbo.NewInstance(
		dubbo.WithName("tag-server"),
		dubbo.WithTag("test-Tag"), // set application's tag
		dubbo.WithRegistry(
			registry.WithNacos(),
			registry.WithAddress(RegistryAddress),
		),
		dubbo.WithProtocol(
			protocol.WithTriple(),
			protocol.WithPort(20000),
		),
	)

Parameters:

• dubbo.WithTag: Sets tag that the instance carries, which used to mark the instance (e.g. Canary Env).

Client side:

atta := map[string]string{
	constant.Tagkey:      "test-tag",
	constant.ForceUseTag: "true", // 使用string类型
}
ctx := context.WithValue(context.Background(), constant.AttachmentKey, atta)
resp, err := svc.Greet(ctx, &greet.GreetRequest{Name: name})

Parameters:

• constant.TagKey: Sets tag that requests carry.
• constant.ForceUseTag: Sets whether to force tag matching.

Untagged traffic is routed only to untagged servers. Tagged traffic can be routed to servers with matching tags or to untagged servers, depending on the force configuration.

For the complete example, please see: Full Example Code.