Communication Between Microservices
Let’s build two microservices. One microservice will generate a Random Number. The other microservice will check whether the generated random number is Even or Odd.
1. Random Number Generator Microservice:
Create a file named random_microservice.py in the microservices directory and add the below code.
Python3
from flask import Flask, jsonifyimport randomapp = Flask(__name__)@app.route("/generate", methods=['GET'])def generate_random_number(): random_number = random.randint(1, 1000) return jsonify({"random_number": random_number})if __name__ == "__main__": app.run(port=8001) |
Here, we created a microservice at port 8001 and defined the API route at /generate. Thus the microservice will run at http://127.0.0.1:8001/generate. The generate_random_number() function will return a random number in JSON format. The random.randint(1, 1000) function will give any random number between 1 to 1000.
Run the random_microservice.py using the Python command:
pythonrandom_microservice.py
Go to http://127.0.0.1:8001/generate in your browser. You can see the JSON output.
Output:
Random Number Generator
2. Even or Odd Checker Microservice:
Create a file named evenodd_microservice.py in the microservices directory and add the below code.
Python3
from flask import Flask, jsonifyimport requestsapp = Flask(__name__)random_microservice_url = "http://127.0.0.1:8001/generate"# Calling the random number generator microservicedef call_random_microservie(): response = requests.get(random_microservice_url) return response.json().get("random_number")@app.route("/check", methods=['GET'])def check_even_odd(): random_number = call_random_microservie() result = "even" if random_number % 2 == 0 else "odd" return jsonify({"random_number": random_number, "result": result})if __name__ == "__main__": app.run(port=8002) |
The second microservice will be running at port 8002. We defined the API route at /check, so the microservice can be called by link http://127.0.0.1:8002/check. In the function check_even_odd(), we are calling our first microservice i.e., random_microservice. We are using the requests function and calling our first microservice through its URL i.e., http://127.0.0.1:8001/generate.
Now that, we have created two microservices. The Even or Odd checker microservice will call the random number generator microservice and get the number and check whether it is even or odd. So make sure you run the random_microservice.py first.
After executing random_microservice.py in one terminal, proceed to open a new terminal window and run the evenodd_microservice.py microservice using the Python command.
pythonevenodd_microservice.py
Go to http://127.0.0.1:8002/check in your browser. You can see the JSON output.
Output
Even or Odd Checker
Congratulations! Your two microservices have effectively established communication. It’s worth noting that in this scenario, we’re employing distinct ports (8001 and 8002) for each microservice. This separation ensures that the two microservices operate on separate servers. Keep in mind that there are various approaches to facilitate communication between microservices. In this case, the communication is synchronous, but asynchronous methods can also be employed as an alternative.
Build Your Own Microservices in Flask
Nowadays Python is everywhere. This is majorly due to its simplicity and wide range of applications. Flask is a lightweight web framework for building web applications in Python. Creating microservices with Flask is straightforward.
In this article, we will start with a basic “hello world” microservice. Following that, we’ll delve into the creation of two distinct microservices and explore how to establish seamless communication between them. So let’s begin with understanding the concept of a Microservice.
What is a microservice?
A microservice is a software architectural style whereby an application is divided into smaller sub-parts. These sub-parts are independent of each other i.e., they are independently deployable and scalable. Each microservice performs a specific function or a single task.
Why do we need microservices?
Imagine an e-commerce app like Amazon or Flipkart. Here the app needs to satisfy many tasks like
Order management: placing orders, tracking status etc.
Cart management: Updating cart, calculating cart value etc.
Customer Profile: Name, email, membership management etc.
As you can see, a single app performs many tasks. However, trying to write code for all these tasks within a single framework can make it complicated and challenging to manage and debug. Hence the concept of microservices came into the picture. Each microservice is designed to perform a single task. Furthermore, microservices possess the ability to communicate with each other whenever it’s required.
Contact Us