Do your best with gRPC with ruby ​​on the server and PHP on the client

Introduction

I would like to use gRPC, which is an RPC framework made by google, to use ruby ​​for the server and PHP for the client, and use API communication between different languages ​​with a common I/F.

The fact that different languages ​​are used is more like a conditional reflection on the reality that PHP cannot build a gRPC server, rather than wanting to enjoy the real pleasure of sharing I/F by IDL definition, which is the merit of gRPC. As a result, the real thrill will come, so I would like to taste it.

When using PHP for the client, there are many places where the server side is introduced with go, so I will use ruby ​​here (yes, go do not know confirmed).

It's not necessary to write an overview here, so let's get started. Here, as an API, I will write that if you specify a domain, the expiration date will be fetched.

INPUT:　FQDN OUTPUT:　yyyy/mm/dd hh:ii:ss

API (gRPC): Prepare common I/F with defined I/O Client (PHP): Request FQDN from API through server Server (ruby): Checks the expiration date of the SSL certificate from the FQDN requested by the client and responds the date via API.

Pre-work

pecl install grpc
pecl install protobuf
vi (Abbreviation)/php.ini
	extension=grpc.so
	extension=protobuf.so

gem install grpc
gem install grpc-tools

mkdir ~/projects/grpc_trial/
cd ~/projects/grpc_trial/

composer require grpc/grpc
composer require google/protobuf

mkdir {protos,php,ruby}

Actual work

vi protos/checkexpires.proto
    (See below)

grpc_tools_ruby_protoc -I ./protos --ruby_out=./ruby --grpc_out=./ruby ./protos/checkexpires.proto
ls ruby/ | grep checkexpires
	checkexpires_pb.rb
	checkexpires_services_pb.rb

protoc --proto_path=./protos --php_out=./php --grpc_out=./php ./protos/checkexpires.proto --plugin=protoc-gen-grpc=/usr/local/bin/grpc_php_plugin
ls php/Checkexpires/
	CheckReply.php  CheckRequest.php  GetSslClient.php

vi checkexpires.rb
    (See below)

vi checkexpires.php
    (See below)

ruby ./checkexpires.rb &
php ./checkexpires.php 
php checkexpires.php example.com
	2021/12/25 23:59:59

checkexpires.proto

syntax = "proto3";

package checkexpires;

import "google/protobuf/timestamp.proto";

service GetSsl {
  rpc getExpire (CheckRequest) returns (CheckReply) {}
}

message CheckRequest {
  string fqdn = 1;
}

message CheckReply {
  google.protobuf.Timestamp timestamp = 1;
}

checkexpires.rb

this_dir = File.expand_path(File.dirname(__FILE__))
lib_dir = File.join(this_dir, 'ruby')
$LOAD_PATH.unshift(lib_dir) unless $LOAD_PATH.include?(lib_dir)

require 'time'
require 'grpc'
require 'checkexpires_services_pb'

class CheckexpiresServer < Checkexpires::GetSsl::Service
  def get_expire(check_req, _unused_call)
    end_at = `openssl s_client -connect #{check_req.fqdn}:443 </dev/null 2>/dev/null|openssl x509 -text | grep "Not After"`
    end_at = end_at.split(' : ').pop
    end_at = end_at.gsub("\n", '')
    end_at = Time.parse(end_at).to_i
    end_at = Time.at(end_at)
    Checkexpires::CheckReply.new(timestamp: end_at)
  end
end

def main
  s = GRPC::RpcServer.new
  s.add_http2_port('localhost:50051', :this_port_is_insecure)
  s.handle(CheckexpiresServer)
  s.run_till_terminated_or_interrupted([1, 'int', 'SIGQUIT'])
end

main

checkexpires.php

<?php
require dirname(__FILE__).'/vendor/autoload.php';
require dirname(__FILE__).'/php/Checkexpires/GetSslClient.php';
require dirname(__FILE__).'/php/Checkexpires/CheckReply.php';
require dirname(__FILE__).'/php/Checkexpires/CheckRequest.php';
require dirname(__FILE__).'/php/GPBMetadata/Checkexpires.php';
$server = 'localhost:50051'; //checkexpires.rb

if (is_null($argv[1] ?? null)) {
    echo "need to input fqdn\n";
    exit(1);
}

try {
    $client = new Checkexpires\GetSslClient($server, [
        'credentials' => Grpc\ChannelCredentials::createInsecure(),
    ]);
    $request = new Checkexpires\CheckRequest();
    $request->setFqdn($argv[1]);
    list($reply, $status) = $client->getExpire($request)->wait();

    if (($status->code ?? null) === 0) {
        $ts = $reply->getTimestamp()->getSeconds();
        echo date('Y/m/d H:i:s', $ts);
        exit(0);
    }
} catch (Exception $e) {
    echo $e->getMessage();
    exit(1);
}

Supplement

Since the common I/F is defined in different languages, let's standardize each compiler as well.

vi ~/.bashrc
	function protoc2() {
	    grpc_tools_ruby_protoc -I ./protos --ruby_out=./ruby --grpc_out=./ruby ./protos/$@ && protoc --proto_path=./protos --php_out=./php --grpc_out=./php ./protos/$@ --plugin=protoc-gen-grpc=/usr/local/bin/grpc_php_plugin
	}

. ~/.bashrc
cd ~/projects/grpc_trial/
protoc2 checkexpires.proto

Now you have a common I/F for ruby ​​and PHP in one proto file. After that, it feels like writing unique processing on the client side and server side respectively. I think I can do my best.