Message Processor

POC: A fun, practical way to play with the Azure Service Bus Emulator + Testcontainers for .NET and see real messages flowing through a local, containerized, event-driven system.
Spin it up. Spam it with events. Watch the worker process them. Magic. 🪄

---

What this project is about

This repository is a proof of concept for building and testing a message-driven .NET worker using:

• ✅ Azure Service Bus Emulator (Docker)
• ✅ Testcontainers for .NET
• ✅ Docker Compose
• ✅ .NET Worker Service

It allows you to:

• Run everything locally
• Send messages into Service Bus
• See the worker process them in real time
• Verify the full pipeline with integration tests

---

Projects

• MessageProcessor.Worker
  The background worker that listens to Azure Service Bus and processes messages.

• MessageProcessor.Tests
  Integration tests using Testcontainers.

• ServiceBus.Spammer
  A small console tool that sends one message per second.
  Location: tools

---

Prerequisites

• Docker
• .NET 10+ SDK

---

Run the full environment

From the folder that contains `docker-compose.yml`:

docker compose up -d

This starts:

• Azure SQL Edge
• Azure Service Bus Emulator
• Service Bus Sentinel (health checker)
• Node greetings-api
• MessageProcessor.Worker
• ServiceBus.Spammer

Verify everything is running:

docker ps

You should see something like:

message-processor-worker   Up ...
servicebus-emulator        Up ...
sqlserver                  Up ...

---

Watch the worker process messages (LIVE)

This is the most important command in the whole project:

docker logs -f message-processor-worker

You should see:

...
Calculating the meaning of life for Message ID fc23a7a9-bbca-4af0-bc4b-86d2517b0c13... please wait.
Received: Message 1326 @ 2025-11-23T03:17:05.7212890Z
...

Leave this terminal open — it is your live processing feed.

---

Run integration tests

These tests use Testcontainers to spin up the required infrastructure automatically.

From the repo root:

dotnet test MessageProcessor.Tests/MessageProcessor.Tests.csproj

Make sure Docker is running before executing the tests.

---

TL;DR — Quick start

docker compose up -d
docker logs -f message-processor-worker

You now have a local, containerized playground for:

• Azure Service Bus Emulator
• Azure Service Bus Emulator Spammer
• .NET worker
• Event-driven systems
• Integration testing

Have fun breaking it, fixing it, and making it better 😄