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‎blog/2023-08-18-microservice-communication-with-laravel-workflow.md

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---
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slug: microservice-communication-with-laravel-workflow
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title: "Microservice Communication with Laravel Workflow"
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authors:
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name: Richard
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title: Core Team
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url: https://github.com/rmcdaniel
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image_url: https://github.com/rmcdaniel.png
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tags: [microservices, laravel-workflow, communication, distributed-systems]
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---
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![captionless image](https://miro.medium.com/v2/resize:fit:1400/format:webp/1*nCy08NPtCpERqC09SVBFfg.jpeg)
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In the evolving landscape of microservices, communication has always been a focal point. Microservices can interact in various ways, be it through HTTP/REST calls, using messaging protocols like RabbitMQ or Kafka, or even employing more recent technologies like gRPC. Yet, regardless of the communication method, the goal remains the same: seamless, efficient, and robust interactions. Today, we’ll explore how Laravel Workflow can fit into this picture and optimize the communication between microservices in a unique way.
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## The Challenge
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In a microservices architecture, decoupling is the name of the game. You want each service to have a single responsibility, to be maintainable, and to be independently deployable. Yet, in the world of workflows, this becomes challenging. How do you split a workflow from its activity and yet ensure they communicate seamlessly?
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## Laravel Workflow to the Rescue!
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[Laravel Workflow](https://github.com/laravel-workflow/laravel-workflow) handles the discovery and orchestration for you! With a shared database and queue connection, you can have your workflow in one Laravel app and its activity logic in another.
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### Defining Workflows and Activities
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#### 1. Create a workflow.
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```php
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use Workflow\ActivityStub;
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use Workflow\Workflow;
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class MyWorkflow extends Workflow
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{
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public function execute($name)
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{
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$result = yield ActivityStub::make(MyActivity::class, $name);
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return $result;
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}
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}
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```
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#### 2. Create an activity.
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```php
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use Workflow\Activity;
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class MyActivity extends Activity
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{
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public function execute($name)
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{
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return "Hello, {$name}!";
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}
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}
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```
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#### 3. Run the workflow.
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```php
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use Workflow\WorkflowStub;
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$workflow = WorkflowStub::make(MyWorkflow::class);
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$workflow->start('world');
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while ($workflow->running());
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$workflow->output();
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// Output: 'Hello, world!'
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```
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The workflow will manage the activity and handle any failures, retries, etc. Think of workflows like job chaining on steroids because you can have conditional logic, loops, return a result that can be used in the next activity, and write everything in typical PHP code that is failure tolerant.
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## Balancing Shared and Dedicated Resources
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When working with microservices, it’s common for each service to have its dedicated resources, such as databases, caches, and queues. However, to facilitate communication between workflows and activities across services, a shared connection (like a database or queue) becomes essential. This shared connection acts as a bridge for data and task exchanges while ensuring:
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1. **Isolation**: Dedicated resources prevent cascading failures.
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2. **Performance**: Each service can be optimized independently.
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3. **Security**: Isolation limits potential attack vectors.
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## Step-By-Step Integration
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### 1. Install `laravel-workflow` in all microservices.
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Follow the [installation guide](https://laravel-workflow.com/docs/installation/).
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### 2. Create a shared database/redis connection in all microservices.
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```php
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// config/database.php
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'connections' => [
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'shared' => [
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'driver' => 'mysql',
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'host' => env('SHARED_DB_HOST', '127.0.0.1'),
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'database' => env('SHARED_DB_DATABASE', 'forge'),
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'username' => env('SHARED_DB_USERNAME', 'forge'),
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'password' => env('SHARED_DB_PASSWORD', ''),
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],
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],
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```
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### 3. Configure a shared queue connection.
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```php
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// config/queue.php
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'connections' => [
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'shared' => [
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'driver' => 'redis',
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'connection' => 'shared',
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'queue' => env('SHARED_REDIS_QUEUE', 'default'),
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],
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],
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```
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### 4. Ensure only one microservice publishes Laravel Workflow migrations.
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Update the migration to use the shared database connection.
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```php
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// database/migrations/..._create_workflows_table.php
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class CreateWorkflowsTable extends Migration
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{
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protected $connection = 'shared';
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}
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```
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### 5. Extend workflow models in each microservice to use the shared connection.
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```php
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// app/Models/StoredWorkflow.php
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namespace App\Models;
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use Workflow\Models\StoredWorkflow as BaseStoredWorkflow;
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class StoredWorkflow extends BaseStoredWorkflow
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{
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protected $connection = 'shared';
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}
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```
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### 6. Publish Laravel Workflow config and update it with shared models.
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```sh
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php artisan vendor:publish --provider="Workflow\Providers\WorkflowServiceProvider" --tag="config"
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```
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### 7. Set workflows and activities to use the shared queue.
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```php
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// app/Workflows/MyWorkflow.php
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class MyWorkflow extends Workflow
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{
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public $connection = 'shared';
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public $queue = 'workflow';
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}
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```
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```php
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// app/Workflows/MyActivity.php
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class MyActivity extends Activity
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{
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public $connection = 'shared';
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public $queue = 'activity';
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}
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```
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### 8. Ensure microservices define empty counterparts for workflow and activity classes.
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#### In the workflow microservice:
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```php
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class MyWorkflow extends Workflow
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{
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public $connection = 'shared';
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public $queue = 'workflow';
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public function execute($name)
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{
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yield ActivityStub::make(MyActivity::class, $name);
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}
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}
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class MyActivity extends Activity
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{
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public $connection = 'shared';
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public $queue = 'activity';
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}
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```
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#### In the activity microservice:
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```php
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class MyWorkflow extends Workflow
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{
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public $connection = 'shared';
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public $queue = 'workflow';
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}
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class MyActivity extends Activity
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{
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public $connection = 'shared';
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public $queue = 'activity';
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public function execute($name)
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{
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return "Hello, {$name}!";
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}
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}
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```
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### 9. Ensure all microservices have the same `APP_KEY` in their `.env` file.
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This is crucial for proper job serialization across services.
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### 10. Run queue workers in each microservice.
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```sh
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php artisan queue:work shared --queue=workflow
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php artisan queue:work shared --queue=activity
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```
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## Conclusion
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By following the steps above, you can ensure seamless interactions between microservices while maintaining modularity and scalability. Laravel Workflow takes care of the discovery and orchestration for you. 🚀
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Thanks for reading!
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