nodejs 使用gRPC

CSDN参考：： http://aihongxin.com/13022.html

npm install -g grpc
或者 
npm i --save-dev @grpc/grpc-js @grpc/proto-loader  (手动生成pb还需 安装grpc-tools)

 package.json

{
  "name": "grpc-examples",
  "version": "0.1.0",
  "dependencies": {
    "@grpc/proto-loader": "^0.5.0",
    "async": "^1.5.2",
    "google-protobuf": "^3.0.0",
    "@grpc/grpc-js": "^1.1.0",
    "lodash": "^4.6.1",
    "minimist": "^1.2.0"
  }
}

 

js 编译proto 

./node_modules/grpc-tools/bin/protoc --js_out=import_style=commonjs,binary:./ --plugin=protoc-gen-grpc=./node_modules/grpc-tools/bin/grpc_node_plugin.exe --grpc_out=./ helloworld.proto

编译后的helloworld_grpc_pb.js 文件中如果无法加载gRPC

var grpc = require('grpc');

可以更改为

var grpc = require('@grpc/grpc-js');

 

grpc 有静态(手动生成pb) 动态加载(加载proto文件无需生成中间文件)两种

 

 

hello_client_static.js

/*
 *
 * Copyright 2015 gRPC authors.
 *
 * Licensed 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.
 *
 */

var parseArgs = require('minimist');
var messages = require('./helloworld_pb');
var services = require('./helloworld_grpc_pb');

var grpc = require('@grpc/grpc-js');

function main() {
  var argv = parseArgs(process.argv.slice(2), {
    string: 'target'
  });
  var target;
  if (argv.target) {
    target = argv.target;
  } else {
    target = 'localhost:5152';
  }
  var client = new services.GreeterClient(target,
                                          grpc.credentials.createInsecure());
  var request = new messages.HelloRequest();
  var user;
  if (argv._.length > 0) {
    user = argv._[0]; 
  } else {
    user = 'world';
  }
  request.setName(user);
  client.sayHello(request, function(err, response) {
    console.log('Greeting:', response.getMessage());
  });
}

main();

 

hello_server_static.js

/*
 *
 * Copyright 2015 gRPC authors.
 *
 * Licensed 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.
 *
 */

var messages = require('./helloworld_pb');
var services = require('./helloworld_grpc_pb');

var grpc = require('@grpc/grpc-js');

/**
 * Implements the SayHello RPC method.
 */
function sayHello(call, callback) {
  var reply = new messages.HelloReply();
  reply.setMessage('Hello ' + call.request.getName());
  callback(null, reply);
}

/**
 * Starts an RPC server that receives requests for the Greeter service at the
 * sample server port
 */
function main() {
  var server = new grpc.Server();
  server.addService(services.GreeterService, {sayHello: sayHello});
  server.bindAsync('0.0.0.0:50051', grpc.ServerCredentials.createInsecure(), () => {
    server.start();
  });
}

main();

 

hello_server_dynamic.js

/*
 *
 * Copyright 2015 gRPC authors.
 *
 * Licensed 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.
 *
 */

var PROTO_PATH = __dirname + '/helloworld.proto';

var grpc = require('@grpc/grpc-js');
var protoLoader = require('@grpc/proto-loader');
var packageDefinition = protoLoader.loadSync(
    PROTO_PATH,
    {keepCase: true,
     longs: String,
     enums: String,
     defaults: true,
     oneofs: true
    });
var hello_proto = grpc.loadPackageDefinition(packageDefinition).helloworld;

/**
 * Implements the SayHello RPC method.
 */
function sayHello(call, callback) {
  callback(null, {message: 'Hello ' + call.request.name});
}

/**
 * Starts an RPC server that receives requests for the Greeter service at the
 * sample server port
 */
function main() {
  var server = new grpc.Server();
  server.addService(hello_proto.Greeter.service, {sayHello: sayHello});
  server.bindAsync('0.0.0.0:50051', grpc.ServerCredentials.createInsecure(), () => {
    server.start();
  });
}

main();

 

hello_client_dynamic.js

/*
 *
 * Copyright 2015 gRPC authors.
 *
 * Licensed 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.
 *
 */

var PROTO_PATH = __dirname + '/../../protos/helloworld.proto';

var parseArgs = require('minimist');
var grpc = require('@grpc/grpc-js');
var protoLoader = require('@grpc/proto-loader');
var packageDefinition = protoLoader.loadSync(
    PROTO_PATH,
    {keepCase: true,
     longs: String,
     enums: String,
     defaults: true,
     oneofs: true
    });
var hello_proto = grpc.loadPackageDefinition(packageDefinition).helloworld;

function main() {
  var argv = parseArgs(process.argv.slice(2), {
    string: 'target'
  });
  var target;
  if (argv.target) {
    target = argv.target;
  } else {
    target = 'localhost:50051';
  }
  var client = new hello_proto.Greeter(target,
                                       grpc.credentials.createInsecure());
  var user;
  if (argv._.length > 0) {
    user = argv._[0]; 
  } else {
    user = 'world';
  }
  client.sayHello({name: user}, function(err, response) {
    console.log('Greeting:', response.message);
  });
}

main();

 

nodejs express 解决跨域请求

app.use(function(req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
    next();
    });