Nats client for php

Feel free to contribute or give any feedback.

Installation
Connection
Publish Subscribe
Request Response
JetStream Api Usage
Microservices
Key Value Storage
Using NKeys with JWT
Performance
Configuration Options

Installation

The recommended way to install the library is through Composer:

$ composer require basis-company/nats

The NKeys functionality requires Ed25519, which is provided in libsodium extension or sodium_compat package.

Connection

use Basis\Nats\Client;
use Basis\Nats\Configuration;

// this is default options, you can override anyone
$configuration = new Configuration([
    'host' => 'localhost',
    'jwt' => null,
    'lang' => 'php',
    'pass' => null,
    'pedantic' => false,
    'port' => 4222,
    'reconnect' => true,
    'timeout' => 1,
    'token' => null,
    'user' => null,
    'nkey' => null,
    'verbose' => false,
    'version' => 'dev',
]);

// default delay mode is constant - first retry be in 1ms, second in 1ms, third in 1ms
$configuration->setDelay(0.001);

// linear delay mode - first retry be in 1ms, second in 2ms, third in 3ms, fourth in 4ms, etc...
$configuration->setDelay(0.001, Configuration::DELAY_LINEAR);

// exponential delay mode - first retry be in 10ms, second in 100ms, third in 1s, fourth if 10 seconds, etc...
$configuration->setDelay(0.01, Configuration::DELAY_EXPONENTIAL);


$client = new Client($configuration);
$client->ping(); // true

Connecting to a cluster with TLS enabled

Typically, when connecting to a cluster with TLS enabled the connection settings do not change. The client lib will automatically switch over to TLS 1.2. However, if you're using a self-signed certificate you may have to point to your local CA file using the tlsCaFile setting.

When connecting to a nats cluster that requires the client to provide TLS certificates use the tlsCertFile and tlsKeyFile to point at your local TLS certificate and private key file.

Nats Server documentation for:

Connection settings when connecting to a nats server that has TLS and TLS Client verify enabled.

use Basis\Nats\Client;
use Basis\Nats\Configuration;

// this is default options, you can override anyone
$configuration = new Configuration([
    'host' => 'localhost',
    'jwt' => null,
    'lang' => 'php',
    'pass' => null,
    'pedantic' => false,
    'port' => 4222,
    'reconnect' => true,
    'timeout' => 1,
    'token' => null,
    'user' => null,
    'nkey' => null,
    'verbose' => false,
    'version' => 'dev',
    'tlsCertFile' => "./certs/client-cert.pem",
    'tlsKeyFile'  => "./certs/client-key.pem",
    'tlsCaFile'  => "./certs/client-key.pem",
]);

$configuration->setDelay(0.001);

$client = new Client($configuration);
$client->ping(); // true

Publish Subscribe

// queue usage example
$queue = $client->subscribe('test_subject');

$client->publish('test_subject', 'hello');
$client->publish('test_subject', 'world');

// optional message fetch
// if there are no updates null will be returned
$message1 = $queue->fetch();
echo $message1->payload . PHP_EOL; // hello

// locks untill message is fetched from subject
// to limit lock timeout, pass optional timeout value
$message2 = $queue->next();
echo $message2->payload . PHP_EOL; // world

$client->publish('test_subject', 'hello');
$client->publish('test_subject', 'batching');

// batch message fetching, limit argument is optional
$messages = $queue->fetchAll(10);
echo count($messages);

// fetch all messages that are published to the subject client connection
// queue will stop message fetching when another subscription receives a message
// in advance you can time limit batch fetching
$queue->setTimeout(1); // limit to 1 second
$messages = $queue->fetchAll();

// reset subscription
$client->unsubscribe($queue);

// callback hell example
$client->subscribe('hello', function ($message) {
    var_dump('got message', $message); // tester
});

$client->publish('hello', 'tester');
$client->process();

// if you want to append some headers, construct payload manually
use Basis\Nats\Message\Payload;

$payload = new Payload('tester', [
    'Nats-Msg-Id' => 'payload-example'
]);

$client->publish('hello', $payload);

Request Response

There is a simple wrapper over publish and feedback processing, so payload can be constructed manually same way.

$client->subscribe('hello.request', function ($name) {
    return "Hello, " . $name;
});

// async interaction
$client->request('hello.request', 'Nekufa1', function ($response) {
    var_dump($response); // Hello, Nekufa1
});

$client->process(); // process request

// sync interaction (block until response get back)
$client->dispatch('hello.request', 'Nekufa2'); // Hello, Nekufa2

JetStream Api Usage

use Basis\Nats\Stream\RetentionPolicy;
use Basis\Nats\Stream\StorageBackend;

$accountInfo = $client->getApi()->getInfo(); // account_info_response object

$stream = $client->getApi()->getStream('mailer');

$stream->getConfiguration()
    ->setRetentionPolicy(RetentionPolicy::WORK_QUEUE)
    ->setStorageBackend(StorageBackend::MEMORY)
    ->setSubjects(['mailer.greet', 'mailer.bye']);

// stream is created with given configuration
$stream->create();

// and put some tasks so workers would be doing something
$stream->put('mailer.greet', 'nekufa@gmail.com');
$stream->put('mailer.bye', 'nekufa@gmail.com');

var_dump($stream->info()); // can stream info

// this should be set in your worker
$greeter = $stream->getConsumer('greeter');
$greeter->getConfiguration()->setSubjectFilter('mailer.greet');
// consumer would be created would on first handle call
$greeter->handle(function ($address) {
    mail($address, "Hi there!");
});

var_dump($greeter->info()); // can consumer info

$goodbyer = $stream->getConsumer('goodbyer');
$goodbyer->getConfiguration()->setSubjectFilter('mailer.bye');
$goodbyer->create(); // create consumer if you don't want to handle anything right now
$goodbyer->handle(function ($address) {
    mail($address, "See you later");
});

// you can configure batching and iteration count using chain api
$goodbyer
    ->setBatching(2) // how many messages would be requested from nats stream
    ->setIterations(3) // how many times message request should be sent
    ->handle(function () {
        // if you need to break on next iteration simply call interrupt method
        // batch will be processed to the end and the handling would be stopped
        // $goodbyer->interrupt();
    });

// consumer can be used via queue interface
$queue = $goodbyer->getQueue();
while ($message = $queue->next()) {
    if (rand(1, 10) % 2 == 0) {
        mail($message->payload, "See you later");
        $message->ack();
    } else {
        // not ack with 1 second timeout
        $message->nack(1);
    }
    // stop processing
    if (rand(1, 10) % 2 == 10) {
        // don't forget to unsubscribe
        $client->unsubscribe($queue);
        break;
    }
}

// use fetchAll method to batch process messages
// let's set batch size to 50
$queue = $goodbyer->setBatching(50)->create()->getQueue();

// fetching 100 messages provides 2 stream requests
// limit message fetching to 1 second
// it means no more that 100 messages would be fetched
$messages = $queue->setTimeout(1)->fetchAll(100);

$recipients = [];
foreach ($messages as $message) {
    $recipients[] = (string) $message->payload;
}

mail_to_all($recipients, "See you later");

// ack all messages
foreach ($messages as $message) {
    $message->ack();
}


// you also can create ephemeral consumer
// the only thing that ephemeral consumer is created as soon as object is created
// you have to create full consumer configuration first
use Basis\Nats\Consumer\Configuration as ConsumerConfiguration;
use Basis\Nats\Consumer\DeliverPolicy;

$configuration = (new ConsumerConfiguration($stream->getName()))
    ->setDeliverPolicy(DeliverPolicy::NEW)
    ->setSubjectFilter('mailer.greet');

$ephemeralConsumer = $stream->createEphemeralConsumer($configuration);

// now you can use ephemeral consumer in the same way as durable consumer
$ephemeralConsumer->handle(function ($address) {
    mail($address, "Hi there!");
});

// the only difference - you don't have to remove it manually, it will be deleted by NATS when socket connection is closed
// be aware that NATS will not remove that consumer immediately, process can take few seconds
var_dump(
    $ephemeralConsumer->getName(),
    $ephemeralConsumer->info(),
);

// if you need to append some headers, construct payload manually
use Basis\Nats\Message\Payload;

$payload = new Payload('nekufa@gmail.com', [
    'Nats-Msg-Id' => 'single-send'
]);

$stream->put('mailer.bye', $payload);

Microservices

The services feature provides a simple way to create microservices that leverage NATS.

In the example below, you will see an example of creating an index function for the posts microservice. The request can be accessed under "v1.posts" and then individual post by "v1.posts.{post_id}".

// Define a service
$service = $client->service(
    'PostsService',
    'This service is responsible for handling all things post related.',
    '1.0'
);

// Create the version group
$version = $service->addGroup('v1');

// Create the index posts endpoint handler
class IndexPosts implements \Basis\Nats\Service\EndpointHandler {

    public function handle(\Basis\Nats\Message\Payload $payload): array
    {
        // Your application logic
        return [
            'posts' => []
        ];
    }
}

// Create the index endpoint
$version->addEndpoint("posts", IndexPosts::class);

// Create the service group
$posts = $version->addGroup('posts');

// View post endpoint
$posts->addEndpoint(
    '*',
    function (\Basis\Nats\Message\Payload $payload) {
        $postId = explode('.', $payload->subject);
        $postId = $postId[count($postId)-1];

        return [
            'post' => []
        ];
    }
);

// Run the service
$service->run();

Key Value Storage

$bucket = $client->getApi()->getBucket('bucket_name');

// basics
$bucket->put('username', 'nekufa');
echo $bucket->get('username'); // nekufa

// safe update (given revision)
$entry = $bucket->getEntry('username');
echo $entry->value; // nekufa
$bucket->update('username', 'bazyaba', $entry->revision);

// delete value
$bucket->delete('username');

// purge value history
$bucket->purge('username');

// get bucket stats
var_dump($bucket->getStatus());

// in advance, you can fetch all bucket values
$bucket->update('email', 'nekufa@gmail.com');
var_dump($bucket->getAll()); // ['email' => 'nekufa@gmail.com', 'username' => 'nekufa']

Using NKeys with JWT

To use NKeys with JWT, simply provide them in the Configuration options as jwt and nkey. You can also provide a credentials file with CredentialsParser

use Basis\Nats\Client;
use Basis\Nats\Configuration;
use Basis\Nats\NKeys\CredentialsParser;

$configuration = new Configuration(
    [
        'host' => 'localhost',
        'port' => 4222
    ],
    CredentialsParser::fromFile($credentialPath)
);

$client = new Client($configuration);

Performance

Testing on AMD Ryzen 5 3600X with nats running in docker gives about 400k rps for publish and 330k rps for receive in non-verbose mode.

You can run tests on your environment.

 % wget https://getcomposer.org/download/latest-stable/composer.phar
...
Saving to: ‘composer.phar’

 % ./composer.phar install
Installing dependencies from lock file (including require-dev)
...

 % export NATS_HOST=0.0.0.0
 % export NATS_PORT=4222
 % export NATS_CLIENT_LOG=1
 % composer run perf-test
PHPUnit 9.5.28 by Sebastian Bergmann and contributors.

Runtime:       PHP 8.3.3-1+ubuntu22.04.1+deb.sury.org+1
Configuration: /home/nekufa/software/github/nats.php/phpunit.xml.dist
Warning:       No code coverage driver available

[2024-03-11T17:06:30.907277+00:00] PerformanceTest.testPerformance.DEBUG: send CONNECT {"headers":true,"pedantic":false,"verbose":false,"lang":"php","version":"dev"}  [] []
[2024-03-11T17:06:30.907312+00:00] PerformanceTest.testPerformance.INFO: start performance test [] []
[2024-03-11T17:06:32.135674+00:00] PerformanceTest.testPerformance.INFO: publishing {"rps":407072.0,"length":500000,"time":1.228281021118164} []
[2024-03-11T17:06:33.412134+00:00] PerformanceTest.testPerformance.INFO: processing {"rps":391723.0,"length":500000,"time":1.2764089107513428} []


 % export NATS_CLIENT_VERBOSE=1
 % composer run perf-test
PHPUnit 9.5.28 by Sebastian Bergmann and contributors.

Runtime:       PHP 8.3.3-1+ubuntu22.04.1+deb.sury.org+1
Configuration: /home/nekufa/software/github/nats.php/phpunit.xml.dist
Warning:       No code coverage driver available

[2024-03-11T17:07:12.829135+00:00] PerformanceTest.testPerformance.DEBUG: send CONNECT {"headers":true,"pedantic":false,"verbose":true,"lang":"php","version":"dev"}  [] []
[2024-03-11T17:07:12.829172+00:00] PerformanceTest.testPerformance.INFO: start performance test [] []
[2024-03-11T17:07:14.069321+00:00] PerformanceTest.testPerformance.INFO: publishing {"rps":403207.0,"length":500000,"time":1.2400550842285156} []
[2024-03-11T17:07:15.548207+00:00] PerformanceTest.testPerformance.INFO: processing {"rps":338104.0,"length":500000,"time":1.4788329601287842} []
.                                                                   1 / 1 (100%)

nekufa@fasiga ~ % cat /proc/cpuinfo | grep AMD
model name	: AMD Ryzen 5 3600X 6-Core Processor

Configuration Options

The following is the list of configuration options and default values.

Option	Default	Description
`inboxPrefix`	`"_INBOX"`	Sets de prefix for automatically created inboxes
`jwt`		Token for JWT Authentication. Alternatively you can use CredentialsParser
`nkey`		Ed25519 based public key signature used for NKEY Authentication.
`pass`		Sets the password for a connection.
`pedantic`	`false`	Turns on strict subject format checks.
`pingInterval`	`2`	Number of seconds between client-sent pings.
`port`	`4222`	Port to connect to (only used if `servers` is not specified).
`timeout`	1	Number of seconds the client will wait for a connection to be established.
`token`		Sets a authorization token for a connection.
`tlsKeyFile`		TLS 1.2 Client key file path.
`tlsCertFile`		TLS 1.2 Client certificate file path.
`tlsCaFile`		TLS 1.2 CA certificate filepath.
`user`		Sets the username for a connection.
`verbose`	`false`	Turns on `+OK` protocol acknowledgements.

basis-company/nats.php