Service Schema

Service-schema was created as a tool to process messages from broker or between microservices, implementing event sourcing and Saga pattern. Based on the concept of "event schema first", service-schema improves things a step further by introducing schema for each service in order to reuse services and schemas in different events through configuration:

• Each event might has one or many services that are listening to it
• Each service has one schema which will be used to validate the input json

Configuration

"require": {
        "micronative/service-schema": "^2.0.0"
},
"repositories": [
    { "type": "vcs", "url": "https://github.com/micronative/service-schema" }
],

Run

composer require micronative/service-schema:2.0.0

Sample code

configs

events.json

[
  {
    "event": "Users.afterSaveCommit.Create",
    "services": [
      "Micronative\\ServiceSchema\\Tests\\Service\\Samples\\CreateContact",
      "Micronative\\ServiceSchema\\Tests\\Service\\Samples\\CreateTask"
    ]
  },
  {
    "event": "Users.afterSaveCommit.Update",
    "services": [
      "Micronative\\ServiceSchema\\Tests\\Service\\Samples\\UpdateContact"
    ]
  }
]

In this events.json:

• There are 02 events that the microservice is listening to:
  • "Users.afterSaveCommit.Create"
  • "Users.afterSaveCommit.Update"
• Each of event have a list of services that listen to the event

services.json

[
  {
    "service": "Micronative\\ServiceSchema\\Tests\\Service\\Samples\\CreateContact",
    "schema": "/jsons/schemas/CreateContact.json",
    "callbacks": [
      "Micronative\\ServiceSchema\\Tests\\Service\\Samples\\PushMessageToSqs",
      "Micronative\\ServiceSchema\\Tests\\Service\\Samples\\PushMessageToLog"
    ]
  },
  {
    "service": "Micronative\\ServiceSchema\\Tests\\Service\\Samples\\UpdateContact",
    "schema": "/jsons/schemas/UpdateContact.json",
    "callbacks": [
      "Micronative\\ServiceSchema\\Tests\\Service\\Samples\\PushMessageToLog"
    ]
  },
  {
    "service": "Micronative\\ServiceSchema\\Tests\\Service\\Samples\\CreateTask",
    "schema": "/jsons/schemas/CreateTask.json"
  }
]

In this services.json:

• There are 03 services:
  • "ServiceSchema\Tests\Service\Samples\CreateContact"
  • "ServiceSchema\Tests\Service\Samples\UpdateContact"
  • "ServiceSchema\Tests\Service\Samples\CreateTask",
• Each service has a schema and a list of callback services

services schema

CreateContact.json

{
  "type": "object",
  "properties": {
    "event": {
      "type": "string",
      "minLength": 0,
      "maxLength": 256
    },
    "time": {
      "type": "string",
      "minLength": 0,
      "maxLength": 256
    },
    "payload": {
      "type": "object",
      "properties": {
        "user": {
          "type": "object",
          "properties": {
            "data": {
              "type": "object"
            },
            "class": {
              "type": "string",
              "default": "\\App\\Entity\\User"
            }
          },
          "required": [
            "data"
          ]
        },
        "account": {
          "type": "object",
          "properties": {
            "data": {
              "type": "object"
            },
            "class": {
              "type": "string",
              "default": "\\App\\Entity\\Account"
            }
          },
          "required": [
            "data"
          ]
        }
      },
      "required": [
        "user",
        "account"
      ],
      "additionalProperties": false
    }
  },
  "required": [
    "event",
    "payload"
  ],
  "additionalProperties": true
}

In this CreateContact.json:

• It requires the message to have "name" and "payload"
• "payload" requires "user" and "account"
• "user" requires "data"
• "account" requires "data"

Event

$event = new Event();
$event->setName("Users.afterSaveCommit.Create");
$event->setTime("20190730123000");
$event->setPayload(["user" => ["data" => ["name" => "Ken"]], "account" => ["data" => ["name" => "Brighte"]]]);
$message = $event->toJson();
// '{"name":"Users.afterSaveCommit.Create","time":"20190730123000","payload":{"user":{"data":{"name":"Ken"}},"account":{"data":{"name":"Brighte"}}}}'
// this message is used to push to SQS or other services

Service

namespace Micronative\ServiceSchema\Tests\Service\Samples;

use Micronative\ServiceSchema\Event\Message;
use Micronative\ServiceSchema\Event\MessageInterface;
use Micronative\ServiceSchema\Service\Service;
use Micronative\ServiceSchema\Service\ServiceInterface;

class CreateContact extends Service implements ServiceInterface
{
    public function consume(MessageInterface $event = null)
    {
        echo "CreateContact";

        return new Message();
    }
}

Processor

// Receive message from SQS or other services
$message = '{"name":"Users.afterSaveCommit.Create","time":"20190730123000","payload":{"user":{"data":{"name":"Ken"}},"account":{"data":{"name":"Brighte"}}}}';
// config the Processor
$processor = new Processor(["events.json"], ["services.json"], "serviceSchemaDir");
// process the message
$result = $processor->process($message);

• In this example, event "Users.afterSaveCommit.Create" has 02 services listening to it (configued in events.json)
  • "Micronative\ServiceSchema\Tests\Service\Samples\CreateContact"
  • "Micronative\ServiceSchema\Tests\Service\Samples\CreateTask"
• When $processor->process(message): CreateContact->run(Event) and CreateTask->run(Event) will be executed.
• Service CreateContact has 02 callback services (configured in services.json):
  • "Micronative\ServiceSchema\Tests\Service\Samples\PushMessageToSqs"
  • "Micronative\ServiceSchema\Tests\Service\Samples\PushMessageToLog"
• When CreateContact->run(Event) returns an Event then PushMessageToSqs->run(Event) and PushMessageToLog->run(Event) will be executed

UUID

Using Ramsey/Uuid to generate event id

Tests

Please refer to tests for sample configs of events, services, schemas and usage of Processor

• tests/jsons/configs/events.json: configuration of events
• tests/jsons/config/services.json: configuration of services
• tests/jsons/configs/schemas/: sample services schemas (CreateContact.json, CreateTask.json, UpdateContact.json)
• tests/Main/ProcessorTest.php: how to config and run the Processor