Running the reference application

This reference application demonstrates how to build a real-time, event-driven, microservices architecture using Temporal, Go, and Vue.js.

See the Architecture for technical information. Below are the steps to run the reference application on your local machine.

Running Temporal Cluster

To run the Temporal cluster, navigate to the temporal/cluster directory and run the following commands:

[This folder contains a clone from the temporalio/docker-compose GitHub repository]

docker compose up

The Temporal Web UI will be available at http://localhost:8080/namespaces/default/workflows. (port might be different if you have other services running on the same port)

Temporal CLI

Note: This step is optional, not needed for running the reference application

Set up an alias for the Temporal CLI to interact with the cluster:

alias temporal_docker="docker exec temporal-admin-tools temporal"

Now you can use temporal_docker command to start workflows, list workflow executions, and more.

Running Admin-Gateway Microservice

The Gateway Service is a Go-based microservice that acts as an entry point for client requests. It exposes REST endpoints, such as /disable_robot, and delegates complex business logic to other services or workflows. The Gateway Service integrates with Temporal.io to initiate asynchronous workflows, such as disabling a robot. Additionally, it communicates with external services, like the Notification Service, to send real-time updates or notifications to users. This architecture provides scalability and decouples client interactions from backend processes, ensuring efficient handling of asynchronous tasks.

To run the Admin-Gateway microservice, navigate to the microservices/admin_gateway directory and run the following commands:

go run ./cmd

Test the Admin-Gateway Microservice

To test the Admin-Gateway microservice, you can use the following curl command:

curl -X POST http://localhost:8081/disable_robot \
     -H "Content-Type: application/json" \
     -d '{"robot_id": "test_robot_101", "user_id": "user000"}'

This should initiate a workflow in the Temporal cluster. Visit the Temporal Web UI to see the workflow execution.

This workflow will not complete because there are no workers running to process the workflow tasks. To complete the workflow, you need to start a Temporal Worker.

Running the Notification Microservice

The notification microservice is a Go-based service that sends real-time, targeted notifications to specific users via WebSockets. It listens for HTTP requests containing a userID and a message, then forwards the message to the corresponding WebSocket connection for the user, enabling real-time updates to the connected client.

To run the Notification microservice, navigate to the microservices/admin_notifications directory and run the following commands:

go run .

Test the Notification Microservice

To test the Notification microservice, you can use the following curl command:

curl -X POST http://localhost:8082/notify \
-H "Content-Type: application/json" \
-d '{"user_id": "user000", "message": "Robot Alpha has been disabled."}'

You should see the User not connected message appear in the client application. This is because we haven't started the web client application to connect to the Notification microservice yet.

Starting a Temporal Worker

The Temporal Worker is a Go-based service responsible for executing workflows and activities initiated by the Gateway Service. The worker handles the actual execution of the business logic, ensuring fault tolerance, retries, and state management for complex workflows. By leveraging Temporal's workflow orchestration, the worker ensures that even in the event of failures, tasks are retried and completed reliably, allowing for resilient and scalable backend operations.

To start a Temporal Worker, navigate to the temporal/workers directory and run the following commands:

go run .

This will start a worker that listens for tasks from the Temporal cluster and processes them. The worker will process the workflow task we created earlier and complete the workflow. You can see the workflow completion in the Temporal Web UI.

Running Web Client Application

To run the client application, navigate to the clients/av1-admin directory and run the following commands:

npm install
npm run serve

The client application will be available at http://localhost:8080/.

Test the Web Client Application

To test the client application, open the browser and navigate to http://localhost:8083/. You should see the client application with a WebSocket connection to the Notification microservice. You can test the full round trip of the architecture by clicking the Disable button in the client application.

• This will send a request to the Admin-Gateway microservice.
• Which will initiate a workflow in the Temporal cluster.
• The Temporal worker will process the workflow task, and inform the notification microservice.
• The Notification microservice will send a real-time notification to the client application via WebSocket.