通过源码安装gRPC扩展
- centos只能通过源码安装
```
git clone -b v1.35.0 https://github.com/grpc/grpc
```
- 构建及安装gRPC核心库
```
$ cd grpc
$ git submodule update --init
$ make
$ sudo make install
```
- 构建并安装gRPC PHP扩展
  
  编译gRPC PHP扩展
```
$ cd grpc/src/php/ext/grpc
$ phpize
$ ./configure
$ make
$ sudo make install
```
  这会将gRPC PHP扩展编译并安装到标准PHP扩展目录中。
更新php.ini
- 更新php.ini
```
extension=grpc.so
```
- 将gRPC PHP库添加为Composer依赖项
  
  您需要将此添加到项目的composer.json文件中。
```
"require": {
    "grpc/grpc": "v1.7.0"
}
```

Protobuf运行时库

Protobuf有两种安装方式：pecl扩展方式和composer包方式。

C实现方式

$ sudo pecl install protobuf

或指定

$ sudo pecl install protobuf-3.4.0

扩展添加到php.ini

extension=protobuf.so

php实现方式

将此添加到您的composer.json文件：
```
"require": {
    "google/protobuf": "^v3.3.0"
}
```

PHP Protoc插件

gRPC PHP protoc插件来生成客户端stub classes。它可以根据.proto服务定义生成服务器和客户端代码。

插件可能会使用新的protobuf版本的新功能，因此也请确保安装的protobuf版本与您构建此插件的grpc版本兼容。

$ git clone -b v1.35.0 https://github.com/grpc/grpc
$ cd grpc
$ git submodule update --init
$ mkdir -p cmake/build
$ pushd cmake/build
$ cmake ../..
$ make protoc grpc_php_plugin
$ make install
$ popd

注意：看官方在quick start章节中Protobuf的安装文档是有误的，以basics tutorial章节的为准（github issue提出）。另外注意在make protoc grpc_php_plugin之后没有生成protoc执行文件的话，可以make install生成相关执行文件。

官方示例

.proto服务定义

.proto文件用于定义服务，并用于生成服务stub classes。

比如官方示例中：

cd grpc/examples/protos

protos/
├── auth_sample.proto
├── BUILD
├── hellostreamingworld.proto
├── helloworld.proto
├── keyvaluestore.proto
├── README.md
└── route_guide.proto

这里我们看下helloworld.proto的rpc定义：

syntax = "proto3";

option java_multiple_files = true;
option java_package = "io.grpc.examples.helloworld";
option java_outer_classname = "HelloWorldProto";
option objc_class_prefix = "HLW";

package helloworld;

// The greeting service definition.
service Greeter {
  // Sends a greeting
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

// The request message containing the user's name.
message HelloRequest {
  string name = 1;
}

// The response message containing the greetings
message HelloReply {
  string message = 1;
}

生成gRPC代码

生成的代码用于rpc客户端。

$ cd examples/php
$ ls -a
composer.json  echo  .gitignore  greeter_client.php  greeter_proto_gen.sh  README.md  route_guide  run_greeter_client.sh

./greeter_proto_gen.sh

看下生成代码的greeter_proto_gen.sh文件内容：

#protoc --proto_path=../protos --php_out=. --grpc_out=. --plugin=protoc-gen-grpc=../../bins/opt/grpc_php_plugin ../protos/helloworld.proto

protoc --proto_path=../protos --php_out=. --grpc_out=. --plugin=protoc-gen-grpc=../../cmake/build/grpc_php_plugin ../protos/helloworld.proto

注意：shell文件中指定了../protos/helloworld.proto服务文件，根据该服务文件生成相应的stub classess。

在当前目录下生成 HelloWorld 目录:

$ tree ./Helloworld/
./Helloworld/
├── GreeterClient.php
├── HelloReply.php
└── HelloRequest.php

GreeterClient.php

namespace Helloworld;

/**
 * The greeting service definition.
 */
class GreeterClient extends \Grpc\BaseStub {

    /**
     * @param string $hostname hostname
     * @param array $opts channel options
     * @param \Grpc\Channel $channel (optional) re-use channel object
     */
    public function __construct($hostname, $opts, $channel = null) {
        parent::__construct($hostname, $opts, $channel);
    }

    /**
     * Sends a greeting
     * @param \Helloworld\HelloRequest $argument input argument
     * @param array $metadata metadata
     * @param array $options call options
     * @return \Grpc\UnaryCall
     */
    public function SayHello(\Helloworld\HelloRequest $argument,
      $metadata = [], $options = []) {
        return $this->_simpleRequest('/helloworld.Greeter/SayHello',
        $argument,
        ['\Helloworld\HelloReply', 'decode'],
        $metadata, $options);
    }

}

composer安装grpc与protobuf包：

$ composer install
Loading composer repositories with package information
Updating dependencies
Lock file operations: 2 installs, 0 updates, 0 removals
  - Locking google/protobuf (v3.15.7)
  - Locking grpc/grpc (1.36.0)
Writing lock file
Installing dependencies from lock file (including require-dev)
Package operations: 2 installs, 0 updates, 0 removals
  - Downloading google/protobuf (v3.15.7)
  - Downloading grpc/grpc (1.36.0)
  - Installing google/protobuf (v3.15.7): Extracting archive
  - Installing grpc/grpc (1.36.0): Extracting archive
Generating autoload files

运行RPC服务器

从examples/node目录：

$ npm install
$ cd dynamic_codegen
$ node greeter_server.js

greeter_servier.js

var PROTO_PATH = __dirname + '/../../protos/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();

执行RPC客户端

在另一个终端的examples/php目录中，运行客户端

$ ./run_greeter_client.sh

输出：

grpc/examples/php$ ./run_greeter_client.sh
PHP Warning:  Module 'grpc' already loaded in Unknown on line 0
Hello world

我们看run_greeter_client.sh的文件内容：

set -e
cd $(dirname $0)
php -d extension=grpc.so -d max_execution_time=300 \
  greeter_client.php $1

再看被执行的业务逻辑代码greeter_client.php：

require dirname(__FILE__).'/vendor/autoload.php';

function greet($hostname, $name)
{
    $client = new Helloworld\GreeterClient($hostname, [
        'credentials' => Grpc\ChannelCredentials::createInsecure(),
    ]);
    $request = new Helloworld\HelloRequest();
    $request->setName($name);
    list($response, $status) = $client->SayHello($request)->wait();
    if ($status->code !== Grpc\STATUS_OK) {
        echo "ERROR: " . $status->code . ", " . $status->details . PHP_EOL;
        exit(1);
    }
    echo $response->getMessage() . PHP_EOL;
}

$name = !empty($argv[1]) ? $argv[1] : 'world';
$hostname = !empty($argv[2]) ? $argv[2] : 'localhost:50051';
greet($hostname, $name);

其实我们已经在cli模式下php.ini中增加了grpc.so扩展，完全可以直接执行业务逻辑php脚本（rpc客户端）：

grpc/examples/php$ php greeter_client.php 9ong.com
Hello 9ong.com

更新gRPC服务

修改RPC服务端代码

打开greeter_server.js，增加方法：（注意两个地方代码调整）

var PROTO_PATH = __dirname + '/../../protos/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});
}
//@9ong 代码调整1
function sayHelloAgain(call, callback) {
    callback(null, {message: 'Hello again' + 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();
//@9ong 代码调整2
server.addService(hello_proto.Greeter.service, {sayHello: sayHello,sayHelloAgain: sayHelloAgain});
server.bindAsync('0.0.0.0:50051', grpc.ServerCredentials.createInsecure(), () => {
    server.start();
});
}

main();

修改.proto服务定义文件

更新helloworld.proto服务定义：

// The greeting service definition.
service Greeter {
    // Sends a greeting
    rpc SayHello (HelloRequest) returns (HelloReply) {}
    rpc SayHelloAgain (HelloRequest) returns (HelloReply) {}
}

重新生成RPC客户端stub classess

/**
* The greeting service definition.
*/
class GreeterClient extends \Grpc\BaseStub {

    /**
    * @param string $hostname hostname
    * @param array $opts channel options
    * @param \Grpc\Channel $channel (optional) re-use channel object
    */
    public function __construct($hostname, $opts, $channel = null) {
        parent::__construct($hostname, $opts, $channel);
    }

    /**
    * Sends a greeting
    * @param \Helloworld\HelloRequest $argument input argument
    * @param array $metadata metadata
    * @param array $options call options
    * @return \Grpc\UnaryCall
    */
    public function SayHello(\Helloworld\HelloRequest $argument,
    $metadata = [], $options = []) {
        return $this->_simpleRequest('/helloworld.Greeter/SayHello',
        $argument,
        ['\Helloworld\HelloReply', 'decode'],
        $metadata, $options);
    }

    /**
    * @param \Helloworld\HelloRequest $argument input argument
    * @param array $metadata metadata
    * @param array $options call options
    * @return \Grpc\UnaryCall
    */
    public function SayHelloAgain(\Helloworld\HelloRequest $argument,
    $metadata = [], $options = []) {
        return $this->_simpleRequest('/helloworld.Greeter/SayHelloAgain',
        $argument,
        ['\Helloworld\HelloReply', 'decode'],
        $metadata, $options);
    }

}

测试执行

业务逻辑代码greeter_client.php:

function greet($hostname, $name)
{
    $client = new Helloworld\GreeterClient($hostname, [
        'credentials' => Grpc\ChannelCredentials::createInsecure(),
    ]);
    $request = new Helloworld\HelloRequest();
    $request->setName($name);
    list($response, $status) = $client->SayHello($request)->wait();
    if ($status->code !== Grpc\STATUS_OK) {
        echo "ERROR: " . $status->code . ", " . $status->details . PHP_EOL;
        exit(1);
    }
    echo $response->getMessage() . PHP_EOL;

    list($reply, $status) = $client->SayHelloAgain($request)->wait();
    echo $reply->getMessage().PHP_EOL;
}

执行：

grpc/examples/php$ php greeter_client.php
Hello world
Hello againworld

参考

Basics tutorial | PHP | gRPC

Quick start | Node | gRPC

gRPC实现RPC服务-PHP客户端nodejs服务端

目录

环境条件

安装gRPC扩展