This guide gets you started with gRPC in PHP with a simple working example.

Prerequisites

  • php 5.5 or above, 7.0 or above
  • pecl
  • composer
  • phpunit (optional)

Install PHP and PECL on Ubuntu/Debian:

For PHP5:

$ sudo apt-get install php5 php5-dev php-pear phpunit

For PHP7:

$ sudo apt-get install php7.0 php7.0-dev php-pear phpunit

or

$ sudo apt-get install php php-dev php-pear phpunit

Install PHP and PECL on CentOS/RHEL 7:

$ sudo rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
$ sudo rpm -Uvh https://mirror.webtatic.com/yum/el7/webtatic-release.rpm
$ sudo yum install php56w php56w-devel php-pear phpunit gcc zlib-devel

Install PHP and PECL on Mac:

$ brew install homebrew/php/php56-grpc
$ curl -O http://pear.php.net/go-pear.phar
$ sudo php -d detect_unicode=0 go-pear.phar

Install Composer (Linux or Mac):

$ curl -sS https://getcomposer.org/installer | php
$ sudo mv composer.phar /usr/local/bin/composer

Install PHPUnit (Linux or Mac):

$ wget https://phar.phpunit.de/phpunit-old.phar
$ chmod +x phpunit-old.phar
$ sudo mv phpunit-old.phar /usr/bin/phpunit

Install the gRPC PHP extension

There are two ways to install gRPC PHP extension.

  • pecl
  • build from source

Using PECL

sudo pecl install grpc

or specific version

sudo pecl install grpc-1.7.0

Note: for users on CentOS/RHEL 6, unfortunately this step won’t work. Please follow the instructions below to compile the PECL extension from source.

Install on Windows

You can download the pre-compiled gRPC extension from the PECL website

Build from Source with gRPC C core library

Clone this repository

$ git clone -b $(curl -L https://grpc.io/release) https://github.com/grpc/grpc

Build and install the gRPC C core library

$ cd grpc
$ git submodule update --init
$ make
$ sudo make install

Build and install gRPC PHP extension

Compile the gRPC PHP extension

$ cd grpc/src/php/ext/grpc
$ phpize
$ ./configure
$ make
$ sudo make install

This will compile and install the gRPC PHP extension into the standard PHP extension directory. You should be able to run the unit tests, with the PHP extension installed.

Update php.ini

After installing the gRPC extension, make sure you add this line to your php.ini file, (e.g. /etc/php5/cli/php.ini, /etc/php5/apache2/php.ini, or /usr/local/etc/php/5.6/php.ini), depending on where your PHP installation is.

extension=grpc.so

Add the gRPC PHP library as a Composer dependency

You need to add this to your project’s composer.json file.

  "require": {
    "grpc/grpc": "v1.7.0"
  }

To run tests with generated stub code from .proto files, you will also need the composer and protoc binaries. You can find out how to get these below.

Install other prerequisites for both Mac OS X and Linux

  • protoc: protobuf compiler
  • protobuf.so: protobuf runtime library
  • grpc_php_plugin: Generates PHP gRPC service interface out of Protobuf IDL

Install Protobuf compiler

If you don’t have it already, you need to install the protobuf compiler protoc, version 3.4.0+ (the newer the better) for the current gRPC version. If you installed already, make sure the protobuf version is compatible with the grpc version you installed. If you build grpc.so from source, you can check the version of grpc inside package.xml file.

The compatibility between the grpc and protobuf version is listed as table below:

grpc protobuf
v1.0.0 3.0.0(GA)
v1.0.1 3.0.2
v1.1.0 3.1.0
v1.2.0 3.2.0
v1.2.0 3.2.0
v1.3.4 3.3.0
v1.3.5 3.2.0
v1.4.0 3.3.0
v1.6.0 3.4.0

If protoc hasn’t been installed, you can download the protoc binaries from the protocol buffers GitHub repository. Then unzip this file and Update the environment variable PATH to include the path to the protoc binary file./protobuf/releases). Then unzip this file and Update the environment variable PATH to include the path to the protoc binary file.

If you really must compile protoc from source, you can run the following commands, but this is risky because there is no easy way to uninstall / upgrade to a newer release.

$ cd grpc/third_party/protobuf
$ ./autogen.sh && ./configure && make
$ sudo make install

Protobuf Runtime library

There are two protobuf runtime libraries to choose from. They are identical in terms of APIs offered. The C implementation provides better performance, while the native implementation is easier to install. Make sure the installed protobuf version works with grpc version.

1. C implementation (for better performance)

$ sudo pecl install protobuf

or specific version

$ sudo pecl install protobuf-3.4.0

After protobuf extension is installed, Update php.ini by adding this line to your php.ini file, (e.g. /etc/php5/cli/php.ini, /etc/php5/apache2/php.ini, or /usr/local/etc/php/5.6/php.ini), depending on where your PHP installation is.

extension=protobuf.so

2. PHP implementation (for easier installation)

Add this to your composer.json file:

  "require": {
    "google/protobuf": "^v3.3.0"
  }

PHP Protoc Plugin

You need the gRPC PHP protoc plugin to generate the client stub classes. It can generate server and client code from .proto service definitions.

It should already been compiled when you run make from the root directory of this repo. The plugin can be found in the bins/opt directory. We are planning to provide a better way to download and install the plugin in the future.

You can also just build the gRPC PHP protoc plugin by running:

$ git clone -b $(curl -L https://grpc.io/release) https://github.com/grpc/grpc
$ cd grpc
$ git submodule update --init
$ make grpc_php_plugin

Plugin may use the new feature of the new protobuf version, thus please also make sure that the protobuf version installed is compatible with the grpc version you build this plugin.

Download the example

You’ll need a local copy of the example code to work through this quickstart. Download the example code from our GitHub repository (the following command clones the entire repository, but you just need the examples for this quickstart and other tutorials):

Note that currently you can only create clients in PHP for gRPC services - you can find out how to create gRPC servers in our other tutorials, e.g. Node.js.

$ # Clone the repository to get the example code:
$ git clone -b v1.20.0 https://github.com/grpc/grpc
$ # Build grpc_php_plugin to generate proto files if not build before
$ cd grpc && git submodule update --init && make grpc_php_plugin
$ # Navigate to the "hello, world" PHP example:
$ cd examples/php
$ ./greeter_proto_gen.sh
$ composer install

Run a gRPC application

From the examples/node directory:

  1. Run the server

    $ npm install
    $ cd dynamic_codegen
    $ node greeter_server.js
    

In another terminal, from the examples/php directory:

  1. Run the client

    $ ./run_greeter_client.sh
    

Congratulations! You’ve just run a client-server application with gRPC.

Update a gRPC service

Now let’s look at how to update the application with an extra method on the server for the client to call. Our gRPC service is defined using protocol buffers; you can find out lots more about how to define a service in a .proto file in gRPC Basics: PHP. For now all you need to know is that both the server and the client “stub” have a SayHello RPC method that takes a HelloRequest parameter from the client and returns a HelloResponse from the server, and that this method is defined like this:

// 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;
}

Let’s update this so that the Greeter service has two methods. Edit examples/protos/helloworld.proto and update it with a new SayHelloAgain method, with the same request and response types:

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

(Don’t forget to save the file!)

Generate gRPC code

Next we need to update the gRPC code used by our application to use the new service definition. From the grpc root directory:

$ protoc --proto_path=examples/protos \
  --php_out=examples/php \
  --grpc_out=examples/php \
  --plugin=protoc-gen-grpc=bins/opt/grpc_php_plugin \
  ./examples/protos/helloworld.proto

or running the helper script under the grpc/example/php directory if you build grpc-php-plugin by source:

$ ./greeter_proto_gen.sh

This regenerates the protobuf files, which contain our generated client classes, as well as classes for populating, serializing, and retrieving our request and response types.

Update and run the application

We now have new generated client code, but we still need to implement and call the new method in the human-written parts of our example application.

Update the server

In the same directory, open greeter_server.js. Implement the new method like this:

function sayHello(call, callback) {
  callback(null, {message: 'Hello ' + call.request.name});
}

function sayHelloAgain(call, callback) {
  callback(null, {message: 'Hello again, ' + call.request.name});
}

function main() {
  var server = new grpc.Server();
  server.addProtoService(hello_proto.Greeter.service,
                         {sayHello: sayHello, sayHelloAgain: sayHelloAgain});
  server.bind('0.0.0.0:50051', grpc.ServerCredentials.createInsecure());
  server.start();
}
...

Update the client

In the same directory, open greeter_client.php. Call the new method like this:

    $request = new Helloworld\HelloRequest();
    $request->setName($name);
    list($reply, $status) = $client->SayHello($request)->wait();
    $message = $reply->getMessage();
    list($reply, $status) = $client->SayHelloAgain($request)->wait();
    $message = $reply->getMessage();

Run!

Just like we did before, from the examples/node/dynamic_codegen directory:

  1. Run the server

    $ node greeter_server.js
    

In another terminal, from the examples/php directory:

  1. Run the client

    $ ./run_greeter_client.sh
    

What’s next