dapr/php-sdk

Dapr Implementation in PHP

v1.1.0 2021-04-10 08:22 UTC

README

This library is licensed with the MIT license.

Add the library to your composer.json:

composer require dapr/php-sdk

Some basic documentation is below, more documentation can be found in the docs;

Accessing Secrets

You can access secrets easily:

<?php

$app = Dapr\App::create();
$app->get('/a-secret/{name}', function(string $name, \Dapr\SecretManager $secretManager) {
    return $secretManager->retrieve(secret_store: 'my-secret-store', name: $name);
});
$app->get('/a-secret', function(\Dapr\SecretManager $secretManager) {
    return $secretManager->all(secret_store: 'my-secret-store');
});
$app->start();

Accessing State

State is just Plain Old PHP Objects (POPO's) with an attribute:

<?php
#[\Dapr\State\Attributes\StateStore('statestore', \Dapr\consistency\EventualLastWrite::class)]
class MyState {
    /**
     * @var string 
     */
    public string $string_value;
    
    /**
     * @var ComplexType[] 
     */
    #[\Dapr\Deserialization\Attributes\ArrayOf(ComplexType::class)] 
    public array $complex_type;
    
    /**
      * @var Exception 
      */
    public Exception $object_type;
    
    /**
     * @var int 
     */
    public int $counter = 0;

    /**
     * Increment the counter
     * @param int $amount Amount to increment by
     */
    public function increment(int $amount = 1): void {
        $this->counter += $amount;
    }
}

$app = \Dapr\App::create();
$app->post('/my-state/{key}', function (
    string $key, 
    #[\Dapr\Attributes\FromBody] string $body, 
    \Dapr\State\StateManager $stateManager) {
        $stateManager->save_state(store_name: 'store', item: new \Dapr\State\StateItem(key: $key, value: $body));
        $stateManager->save_object(new MyState);
});
$app->get('/my-state/{key}', function(string $key, \Dapr\State\StateManager $stateManager) {
    return $stateManager->load_state(store_name: 'store', key: $key);
});
$app->start();

Transactional State

You can also use transactional state to interact with state objects by extending TransactionalState with our state objects.

#[\Dapr\State\Attributes\StateStore('statestore', \Dapr\consistency\StrongFirstWrite::class)]
class SomeState extends \Dapr\State\TransactionalState {
    public string $value;
    public function ok(): void {
        $this->value = 'ok';
    }
}

$app = Dapr\App::create();
$app->get('/do-work', function(SomeState $state) {
    $state->begin();
    $state->value = 'not-ok';
    $state->ok();
    $state->commit();
    return $state;
});
$app->start();

Actors

Actors are fully implemented and quite powerful. In order to define an actor, you must first define the interface. You'll likely want to put this in a separate library for easy calling from other services.

<?php
/**
 * Actor that keeps a count
 */
 #[\Dapr\Actors\Attributes\DaprType('ExampleActor')]
interface ICounter {
    /**
     * Increment a counter
     */
    public function increment(int $amount): void;
}

Once the interface is defined, you'll need to implement the behavior and register the actor.

<?php

class CountState extends \Dapr\Actors\ActorState {
    public int $count = 0;
}

#[\Dapr\Actors\Attributes\DaprType('Counter')]
class Counter extends \Dapr\Actors\Actor implements ICounter {
    /**
     * Initialize the class
     */
    public function __construct(string $id, private CountState $state) {
        parent::__construct($id);
    }

    /**
     * Increment the count by 1
     */
    public function increment(int $amount): void {
        $this->state->count += $amount;
    }
}

// register the actor with the runtime
$app = \Dapr\App::create(configure: fn(\DI\ContainerBuilder $builder) => $builder->addDefinitions([
    'dapr.actors' => [Counter::class]
]));
$app->start();

The state to inject is read from the constructor arguments, the state must derive from ActorState to be injected. You may use as many state classes as you'd like. State is automatically saved for you if you make any changes to it during the method call using transactional state.

The Actor base class gives you access to some helper functions and saves you from writing some boiler-plate. You may also implement IActor and use the ActorTrait as well.

Calling an Actor

In order to call an actor, simply call the ActorProxy and get a proxy object:

<?php
use Dapr\Actors\ActorProxy;

 $app = \Dapr\App::create();
 $app->get('/increment/{actorId}[/{amount:\d+}]', function(string $actorId, ActorProxy $actorProxy, int $amount = 1) {
    $counter = $actorProxy->get(ICounter::class, $actorId);
    $counter->increment($amount);
    $counter->create_reminder('increment', new \Dapr\Actors\Reminder('increment', new DateInterval('PT10M'), data: 10 ));
 });
$app->start();

Actor Limitations

  1. There's no re-entrance to an actor, this can cause deadlocks if you're not careful.
  2. By design, static functions don't work.
  3. There's overhead cost in calling "getter" functions.

More detail here: https://docs.dapr.io/developing-applications/building-blocks/actors/actors-overview/

Pub/Sub

Delivering events around your application is an important aspect of any application. This is supported by Dapr, and implemented in this SDK.

Publishing

In order to publish an event, you just instantiate the Publish object with the FactoryInterface:

<?php
$app = \Dapr\App::create();
$app->get('/publish', function(\DI\FactoryInterface $factory) {
    $publisher = $factory->make(\Dapr\PubSub\Publish::class, ['pubsub' => 'redis-pubsub']);
    $publisher->topic('my-topic')->publish(['message' => 'arrive at dawn']);
});
$app->start();

Subscribing

$app = \Dapr\App::create(configure: fn(\DI\ContainerBuilder $builder) => $builder->addDefinitions([
    'dapr.subscriptions' => [new \Dapr\PubSub\Subscription('redis-pubsub', 'my-topic', '/receive-message')]
]));
$app->post('/receive-message', function(#[\Dapr\Attributes\FromBody] \Dapr\PubSub\CloudEvent $event) {
 // do something
});
$app->start();

Serializing

If you need to register a custom serializer, you can completely override the built-in serializers on a per-type basis or even the default serializers:

// register a custom type serializer
$app = \Dapr\App::create(configure: fn(\DI\ContainerBuilder $builder) => $builder->addDefinitions([
    'dapr.serializers.custom' => [MyType::class => [MyType::class, 'serialize']],
    'dapr.deserializers.custom' => [MyType::class => [MyType::class, 'deserialize']],
]));

// get the serializer to do manual serializations
$app->get('/', function(\Dapr\Serialization\ISerializer $serializer) {
    return $serializer->as_array('anything here');
});
$app->start();

Development

Simply run composer start on a machine where dapr init has already been run. This will start the daprd service on the current open terminal. Then navigate to http://localhost:9502/do_tests to let the integration tests run.

Tests

Simply run composer test to run the unit tests. You can lint using composer lint.

Integration tests

You need docker-compose and jq

Build and start the environment, then run the integration tests and clean up.

# clean up any existing environment
docker-compose down -v
# build and deploy the containers
composer start
# run and display the test rusults
composer integration-tests | jq .

You should see output like:

{
  "/test/actors": {
    "status": {
      "test completed successfully: ": ""
    },
    "results": {
      "Empty actor should have no data: ": "",
      "Actor should have data: ": "",
      "Reminder should increment: ": "",
      "time formats are delivered ok: ": "",
      "Timer should increment: ": "",
      "[object] saved array should match: ": "",
      "[object] saved string should match: ": "",
      "actor can return a simple value: ": ""
    }
  },
  "/test/binding": {
    "status": {
      "test completed successfully: ": ""
    },
    "results": {
      "we should have received at least one cron: ": ""
    }
  },
  "/test/invoke": {
    "status": {
      "test completed successfully: ": ""
    },
    "results": {
      "Should receive a 200 response: ": "",
      "Static function should receive json string: ": ""
    }
  },
  "/test/pubsub": {
    "status": {
      "test completed successfully: ": ""
    },
    "results": {
      "simple-test": {
        "sub received message: ": "",
        "Received this data": {
          "id": "57b4a889-3cbb-4d5d-a6fe-7574b097c34c",
          "source": "dev",
          "specversion": "1.0",
          "type": "com.dapr.event.sent",
          "datacontenttype": "application/json",
          "data": [
            "test_event"
          ],
          "traceid": "00-222a0988ecf9d53a006a35f961229788-6706c11d588c6da2-00"
        },
        "should be valid cloud event: ": ""
      },
      "Testing custom cloud event": {
        "sub received message: ": "",
        "Received this raw data": {
          "id": "123",
          "source": "http://example.com",
          "specversion": "1.0",
          "type": "com.example.test",
          "datacontenttype": "application/json",
          "subject": "yolo",
          "time": "2021-02-21T09:32:35+00:00Z",
          "data": [
            "yolo"
          ],
          "traceid": "00-222a0988ecf9d53a006a35f961229788-a0880db7ab9a97d3-00"
        },
        "Expecting this data": {
          "id": "123",
          "source": "http://example.com",
          "specversion": "1.0",
          "type": "com.example.test",
          "datacontenttype": "application/json",
          "subject": "yolo",
          "time": "2021-02-21T09:32:35+00:00Z",
          "data": [
            "yolo"
          ]
        },
        "Received this decoded data": {
          "id": "123",
          "source": "http://example.com",
          "specversion": "1.0",
          "type": "com.example.test",
          "datacontenttype": "application/json",
          "subject": "yolo",
          "time": "2021-02-21T09:32:35+00:00Z",
          "data": [
            "yolo"
          ]
        },
        "Event should be the same event we sent, minus the trace id.: ": ""
      },
      "Publishing raw event": {
        "sub received message: ": "",
        "Received this data": {
          "id": "01e9fef4-7774-4684-9249-cdce032a2713",
          "source": "dev",
          "specversion": "1.0",
          "type": "com.dapr.event.sent",
          "datacontenttype": "application/json",
          "data": {
            "datacontenttype": "text/xml",
            "data": "<note><to>User1</to><from>user2</from><message>hi</message></note>",
            "specversion": "1.0",
            "type": "xml.message",
            "source": "https://example.com/message",
            "subject": "Test XML Message",
            "id": "id-1234-5678-9101",
            "time": "2020-09-23T06:23:21Z"
          },
          "traceid": "00-222a0988ecf9d53a006a35f961229788-d90a5a50ffa8c104-00"
        }
      },
      "Binary response": {
        "raw": {
          "id": "3a5936e4-9bce-41e5-b344-f7e9bfb186f5",
          "source": "dev",
          "specversion": "1.0",
          "type": "com.dapr.event.sent",
          "datacontenttype": "application/json",
          "data": "raw data",
          "traceid": "00-222a0988ecf9d53a006a35f961229788-d579f3a753fa6b45-00"
        },
        "Data properly decoded: ": ""
      }
    }
  },
  "/test/state/concurrency": {
    "status": {
      "test completed successfully: ": ""
    },
    "results": {
      "initial value correct: ": "",
      "Starting from 0: ": "",
      "last-write update succeeds: ": "",
      "first-write update fails": ""
    }
  },
  "/test/state": {
    "status": {
      "test completed successfully: ": ""
    },
    "results": {
      "state is empty: ": "",
      "initial state is correct: ": "",
      "saved correct state: ": "",
      "properly loaded saved state: ": "",
      "prefix should work: ": "",
      "single key read with default: ": "",
      "single key write: ": ""
    }
  }
}