Using Nacos as the Registry

This example shows dubbo-go’s service discovery feature with Nacos as the registry. You can view the complete example source code in dubbo-go-samples.

How to Start

Start the Nacos Server

Follow this instruction to install and start the Nacos server.

Server Registration Configuration

API Configuration

ins, _ := dubbo.NewInstance(
		dubbo.WithName("dubbo_registry_nacos_server"),
		dubbo.WithRegistry(
			registry.WithNacos(),
			registry.WithAddress(nacosAddr),
		),
		dubbo.WithProtocol(
			protocol.WithTriple(),
			protocol.WithPort(20000),
		),
	)

The meaning of each configuration item is as follows:

• dubbo.WithName() sets the application name. After the service is registered, dubbo_registry_nacos_server generates the corresponding application node in Nacos. (This is the example name)
• dubbo.WithRegistry() adds the registry configuration.
  • registry.WithNacos() specifies Nacos as the registry type.
  • registry.WithAddress() sets the Nacos address.
• dubbo.WithProtocol() adds the protocol configuration for the service provider.
  • protocol.WithTriple() specifies the Triple protocol to expose the service.
  • protocol.WithPort() sets the protocol listening port. The example uses 20000.

After the service is successfully registered, you can see the service address under the /services/dubbo_registry_nacos_server node in Nacos.

YAML Configuration

If you pass the configuration through a configuration file instead of the API, please refer to the following YAML configuration.

dubbo:
  registries:
    demoNacos:
      protocol: nacos
      timeout: 10s
      address: 127.0.0.1:8848
  protocols:
    tripleProtocol:
      name: tri
      port: 20000
  provider:
    services:
      GreetTripleServer:
        interface: greet.GreetService

Client Service Discovery Configuration

API Configuration

ins, _ := dubbo.NewInstance(
		dubbo.WithName("dubbo_registry_nacos_client"),
		dubbo.WithRegistry(
			registry.WithNacos(),
			registry.WithAddress("127.0.0.1:8848"),
		),
	)

There is no need to use dubbo.WithProtocol() to configure the protocol here.

YAML Configuration

dubbo:
  registries:
    demoNacos:
      protocol: nacos
      timeout: 3s
      address: 127.0.0.1:8848
  consumer:
    references:
      GreetServiceImpl:
        protocol: tri
        interface: greet.GreetService
        registry: demoNacos
        retries: 3
        timeout: 3000

How to Run

Before running the example, make sure Nacos is started. You can follow install and start the Nacos server to start it, or choose to start it using a Docker image:

docker run -d --name dubbo-go-nacos -e MODE=standalone -p 8848:8848 -p 9848:9848 nacos/nacos-server:v2.3.2

The JVM memory size of Nacos can be configured as needed, for example by limiting its heap memory with -e JVM_XMS=256m -e JVM_XMX=256m.

docker ps --filter name=dubbo-go-nacos

You should see that the Nacos container is running.

Then download the example repository and enter the Nacos example directory:

git clone https://github.com/apache/dubbo-go-samples.git
cd dubbo-go-samples/registry/nacos

Start the Server

Run in the first terminal:

go run ./go-server/cmd/server.go

The service provider listens on port 20000. Open another terminal and confirm that the service is available with an HTTP request:

$ curl \
    --header "Content-Type: application/json" \
    --data '{"name": "Dubbo"}' \
    http://localhost:20000/greet.GreetService/Greet

Expected response:

{"greeting":"Dubbo"}

View the Registered Data

Method 1: Through the Nacos console

Open http://localhost:8848/nacos/ in a browser, go to “Service Management → Service List”, and check whether the dubbo_registry_nacos_server service exists. The table also shows the IP, port, ephemeral instances, weight, health status, metadata, and other data.

Method 2: Through the Nacos OpenAPI

curl -X GET 'http://127.0.0.1:8848/nacos/v1/ns/instance/list?serviceName=dubbo_registry_nacos_server&groupName=DEFAULT_GROUP'

In the expected output, the hosts list should not be empty, and healthy should be true.

Run the Client

Keep the server running, open a second terminal, and run:

$ go run ./go-client/cmd/client.go

After execution, the terminal outputs multiple lines of service discovery and invocation logs, including the following response:

Greet response: greeting:"hello world"

This shows that the client has found the service provider through Nacos and completed the invocation.