Skip to main content
In this lesson, we’ll walk through our example architecture and the HTTP endpoints each service exposes. We have two simple Dockerized microservices:
  1. A Node.js service (runs on port 5000)
  2. A Spring Boot service (runs on port 8080)
Both services communicate via REST APIs, demonstrating best practices for containerization and orchestration.

​
Node.js Microservice (Port 5000)

This lightweight Node.js application is packaged in Docker and listens on port 5000. It offers a single endpoint: GET /plusone/
  • Function: Takes an integer and returns its value plus one.
  • Example Request: 
    curl http://localhost:5000/plusone/41
# 42
Ensure Docker is running and the container is listening on port 5000 before invoking this endpoint.

​
Spring Boot Microservice (Port 8080)

The Spring Boot application exposes three REST endpoints on port 8080. It illustrates service-to-service calls and conditional logic.
EndpointDescriptionExample
GET /Returns a welcome messagecurl http://localhost:8080/
GET /increment/Forwards {number} to Node.js /plusone endpoint and returns the incremented resultcurl http://localhost:8080/increment/41 → 42
GET /compare/Compares {number} against 50 and returns a descriptive messagecurl http://localhost:8080/compare/77 → "77 is greater than 50"

​
1. GET /

Returns a simple greeting from the Spring Boot service: 
curl http://localhost:8080/
# "Welcome to the Spring Boot service!"

​
2. GET /increment/

This endpoint demonstrates inter-service communication. It sends the provided number to the Node.js /plusone service and returns the incremented result. 
curl http://localhost:8080/increment/41
# 42

​
3. GET /compare/

Performs a conditional check on the input number:
  • If number ≤ 50: returns "{number} is less than or equal to 50".
  • If number > 50: returns "{number} is greater than 50".
curl http://localhost:8080/compare/50
curl http://localhost:8080/compare/77
# "77 is greater than 50"
Port conflicts can occur if other services use ports 5000 or 8080. Always verify available ports before starting the containers.

​
Course Roadmap

Throughout this course, you will:
  • Containerize and Dockerize the Spring Boot application.
  • Deploy Spring Boot securely on Kubernetes with best practices.
  • Leverage an existing Docker image for the Node.js service.
  • Explore service-to-service REST communication and error handling.
By the end, you’ll have a fully functioning microservices demo running on Kubernetes, complete with automated builds and deployments. Let’s dive in!

Watch Video