01-basic-messaging

01. Basic Messaging (Simple Queue)

Overview

This directory contains the foundational implementation of a Point-to-Point (P2P) messaging pattern. It demonstrates how a Publisher sends a batch of 10 messages to a specific queue and how a Consumer retrieves and processes them.

This example highlights the decoupling of systems: the publisher doesn't need to know if the consumer is active when the messages are sent.

Technology Stack

• Language: Python 3.x
• Message Broker: RabbitMQ
• Library: pika (Python RabbitMQ client)

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Messaging Features Demonstrated

• Queue Durability: The ABC queue is marked as durable to survive broker restarts.
• Message Persistence: Messages are marked as persistent to prevent data loss.
• Manual Acknowledgments (ACK): The consumer explicitly tells RabbitMQ when a message is processed.
• Fair Dispatch: Uses prefetch_count=1 to ensure the consumer only receives one message at a time.

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Setup & Prerequisites

1. Install Dependencies

pip install pika

2. Environment Configuration

The project is pre-configured with default values. You can find a template in .env.example.

• Note: If you use the automated script (run_demo.sh), it will handle all environment variables for you automatically.

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Running the Demo

Automated

The easiest way to run the project on Linux/macOS is using the provided shell script. It handles Docker setup, environment variables, and execution in one command:

chmod +x run_demo.sh
./run_demo.sh

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Manual

If you prefer to run the components manually, follow these steps:

Step 1: Run RabbitMQ

Option A: Using Docker (Recommended)

docker run -d --name rabbitmq -p 5672:5672 -p 15672:15672 rabbitmq:3-management

Option B: Local Installation (No Docker)

If you prefer not to use Docker, follow the official installation guides:

• Windows: Install via Chocolatey (choco install rabbitmq) or the official installer.
• macOS: Install via Homebrew (brew install rabbitmq).
• Linux (Ubuntu/Debian): sudo apt-get install rabbitmq-server. Once installed, ensure the service is running: sudo service rabbitmq-server start.

Step 2: Start the Consumer

The consumer will wait for messages to arrive in the ABC queue.

python3 consumer.py

Step 3: Run the Publisher

The publisher will send 10 messages to the queue and then exit.

python3 publisher.py

Result: You will see the consumer receive, process, and acknowledge each of the 10 messages in real-time.