Building a Messaging System with NATS, Python, and Azure Kubernetes Service
This article walks you through building a messaging system with NATS (an acronym for Neural Autonomic Transport System) and Python deployed in Azure Kubernetes Service (AKS). NATS is an open-source messaging system. NATS has a core publish-subscribe server designed for performance, scalability, and ease of use.
Before we start, make sure you have the following:
- An active Azure subscription.
- The Azure CLI
azinstalled and configured.
- Python 3 and pip installed.
- Docker installed.
- Kubernetes CLI
kubectlinstalled and configured.
- Helm: We’ll use Helm to deploy NATS on our Kubernetes cluster.
Table of Contents
- Deploying NATS on Azure Kubernetes Service
- Creating a Python Publisher and Subscriber
- Running the Python Applications in Kubernetes
- Deploying to Kubernetes and Testing
Deploying NATS on Azure Kubernetes Service
First, we need to create a Kubernetes cluster on AKS. Use the following
az CLI commands:
Next, we’ll deploy a NATS server on our AKS cluster. We can do this easily using Helm, a package manager for Kubernetes. With Helm installed and your, AKS cluster up and running, execute the following commands to add the NATS Helm chart repo and install NATS:
The above command deploys a single server NATS setup onto your cluster.
Creating a Python Publisher and Subscriber
Next, we’ll create a publisher and a subscriber application using Python. The publisher will publish messages to a NATS subject, and the subscriber will subscribe to this subject to receive these messages. Here’s a simple example of a publisher in the
And here’s a Python subscriber
These scripts will send and receive a “Hello World” message through NATS.
Running the Python Applications in Kubernetes
Package your Python applications as Docker containers and deploy them onto your AKS cluster. Here are basic
Dockerfile examples for both applications:
Dockefile for Publisher:
Dockerfile for Subscriber:
Then, build and push these Docker images to a Docker registry accessible by your AKS cluster.
Deploying to Kubernetes and Testing
After preparing the Docker images, we can deploy our Python applications to our AKS cluster. We’ll use Kubernetes Deployments and Services to manage our applications. Here are basic examples for the publisher and subscriber:
Kubernetes Publisher Deployment Spec:
Kubernetes Subscriber Deployment Spec:
Deploy these Kubernetes objects using
kubectl apply -f <file-name>. Once the Deployments and Services are active, the publisher will send messages, and the subscriber will receive them.
To verify that our system is working correctly, we can check the logs of our subscriber:
If everything is set up correctly, you should see
"Received a message on foo: Hello World" in the logs.
In this guide, we built a distributed messaging system using NATS, Python, and Azure Kubernetes Service. We deployed a NATS server onto AKS, made Python publisher and subscriber applications, packaged them as Docker containers, and ran them on AKS.
This guide is a basic introduction to NATS, Python, and AKS. Feel free to expand upon this guide to build more complex systems tailored to your needs.
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