egg-rpc

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[download-url]: https://npmjs.org/package/egg-rpc-base

egg-rpc plugin for egg framework

Install

``bash
$ npm i egg-rpc-base --save
`

Usage

$3

Change ${app_root}/config/plugin.js to enable egg-rpc plugin:

`js
exports.rpc = {
enable: true,
package: 'egg-rpc-base',
};
`

$3

By default, We use zookeeper for service discovery. Therefore you need to configure the zk address:

`js
// ${app_root}/config/config.${env}.js
config.rpc = {
registry: {
address: '127.0.0.1:2181', // configure your real zk address
},
};
`

We plan to provide more implementations of service discovery. And also you can implement it by yourself, you can follow this article

$3

By using the plugin, you can call rpc services provided by other system.

#### 1. Get the RPC Interface Definition

We use protobuf interface definition lanaguge to describe the RPC service. So you need to get the \*.proto files and put them into ${app_root}/proto folder

#### 2. Global RPC Client Configuration

Configure RPC Client information in ${app_root}/config/config.{env}.js:

`js
// ${app_root}config/config.${env}.js
exports.rpc = {
client: {
responseTimeout: 3000,
},
};
`

- responseTimeout(optional): RPC timeout in milliseconds, default value is 3000

#### 3. Configure the Interface in proxy.js

${app_root}/config/proxy.js is a very important config file for rpc client, you should configure the services you needed, then executing the egg-rpc-generator tool to generate the proxy files.

Let's see a simple example of proxy.js. It declare a interface named: org.eggjs.rpc.test.ProtoService provided by rpc-demo application

`js
'use strict';

module.exports = {
services: [{
appName: 'rpc-demo',
api: {
ProtoService: 'org.eggjs.rpc.test.ProtoService',
},
}],
};
`

Refer this acticle for more details

#### 4. Generate the Proxy

Run egg-rpc-generator to generate the proxy files. After running success, it will generate a file: ProtoService.js under ${app_root}/app/proxy

`bash
$ egg-rpc-generator

[EggRpcGenerator] framework: /egg-rpc-demo/node_modules/egg, baseDir: /egg-rpc-demo
[ProtoRPCPlugin] found "org.eggjs.rpc.test.ProtoService" in proto file
[ProtoRPCPlugin] save all proto info into "/egg-rpc-demo/run/proto.json"
`

#### 5. Call the Service

You can call the RPC service by using ctx.proxy.proxyName. The proxyName is key value of api object you configure in proxy.js. In our example, it's ProtoService, and proxyName using lower camelcase, so it's ctx.proxy.protoService

`js
'use strict';

const Controller = require('egg').Controller;

class HomeController extends Controller {
async index() {
const { ctx } = this;
const res = await ctx.proxy.protoService.echoObj({
name: 'gxcsoccer',
group: 'A',
});
ctx.body = res;
}
}

module.exports = HomeController;
`

As above, you can call remote service as a local method.

$3

By using the plugin, you also can publish your own RPC service to other system.

#### 1. Define the RPC Interface

Writing the \*.proto files, and put them into ${app_root}/proto folder

`


ProtoService.proto

enum Group {
A = 0;
B = 1;
}
`

#### 2. Global RPC Server Configuration

Configure RPC Server information in ${app_root}/config/config.{env}.js:

`js
module.exports = {
rpc: {
server: {
namespace: 'org.eggjs.rpc.test',
},
},
},
`

- namespace(required): the default namespace of all rpc service
- selfPublish(optional): whether every node process publish service independent, default is true
- port(optional): the TCP port will be listen on
- maxIdleTime(optional): server will disconnect the socket if idle for long time
- responseTimeout(optional): Number of milliseconds to wait for a response to begin arriving back from the remote system after sending a request
- codecType(optional): recommended serialization method，default is protobuf

#### 3. Implemenation the RPC Interface

Put your implementation code under ${app_root}/app/rpc folder

`js
// ${app_root}/app/rpc/ProtoService.js
exports.echoObj = async function(req) {
return {
code: 200,
message: 'hello ' + req.name + ', you are in ' + req.group,
};
};
`

#### 4. RPC Unittest in Eggjs

RPC Client Unittest (mock)

`js
'use strict';

const mm = require('egg-mock');
const assert = require('assert');

describe('test/mock.test.js', () => {
let app;
before(async function() {
app = mm.app({
baseDir: 'apps/mock',
});
await app.ready();
});
afterEach(mm.restore);
after(async function() {
await app.close();
});

it('should app.mockProxy ok', async function() {
app.mockProxy('DemoService', 'sayHello', async function(name) {
await sleep(1000);

return 'hello ' + name + ' from mock';
});

const ctx = app.createAnonymousContext();
const res = await ctx.proxy.demoService.sayHello('gxcsoccer');
assert(res === 'hello gxcsoccer from mock');
});
});
`

RPC Server Unittest

`js
'use strict';

const mm = require('egg-mock');

describe('test/index.test.js', () => {
let app;
before(async function() {
app = mm.app({
baseDir: 'apps/rpcserver',
});
await app.ready();
});
after(async function() {
await app.close();
});

it('should invoke HelloService', done => {
app.rpcRequest('org.eggjs.rpc.test.HelloService')
.invoke('hello')
.send([ 'gxcsoccer' ])
.expect('hello gxcsoccer', done);
});
});
`

For more details of app.rpcRequest`, you can refer to this acticle

Docs

- RPC in Nodejs Part One
- Cross-Language Interoperability between Eggjs & SOFA
- Custom Service Discovery in Eggjs
- RPC Proxy Configuration in Eggjs
- RPC Unittest in Eggjs

How to Contribute

Please let us know how can we help. Do check out issues for bug reports or suggestions first.

To become a contributor, please follow our contributing guide.

License

MIT