Demo Running Microservices Local Machine

In this tutorial, we’ll set up and run two cooperating microservices on your local machine:

1. Spring Boot “numeric” service
2. Node.js “plus-one” service (packaged in Docker)

By the end, you’ll be able to call endpoints on the Spring Boot app that delegate to the Node.js service and observe the logs in both environments.

1. Clone and Import the Project

1. Clone the Git repository and open it in your IDE of choice (Spring Tool Suite, IntelliJ, VSCode, etc.).

   

2. Import the project as a Maven project:

   

2. Inspect the Maven POM

Open the pom.xml file at the project root. You’ll find the Spring Boot parent and starter dependencies:

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="
           http://maven.apache.org/POM/4.0.0
           http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>numeric</groupId>
  <artifactId>numeric</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>numeric</name>
  <description>Demo for DevSecOps</description>

  <properties>
    <java.version>1.8</java.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

For more details on Maven POM configuration, refer to the Maven Reference Documentation.

3. Review the Spring Boot Controller

The core logic resides in NumericController.java. It defines three endpoints:

package com.devsecops;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.client.RestTemplate;

@RestController
public class NumericController {
    private final Logger logger = LoggerFactory.getLogger(getClass());

    // For Kubernetes use:
    private static final String baseURL = "http://node-service:5000/plusone";
    // For local testing, uncomment the line below and comment out the Kubernetes URL:
    // private static final String baseURL = "http://localhost:5000/plusone";

    private final RestTemplate restTemplate = new RestTemplate();

    @GetMapping("/")
    public String welcome() {
        return "Kubernetes DevSecOps";
    }

    @GetMapping("/compare/{value}")
    public String compareToFifty(@PathVariable int value) {
        return (value > 50) ? "Greater than 50" : "Smaller than or equal to 50";
    }

    @GetMapping("/increment/{value}")
    public ResponseEntity<String> increment(@PathVariable int value) {
        logger.info("Value received in request: " + value);
        ResponseEntity<String> response =
            restTemplate.getForEntity(baseURL + "/" + value, String.class);
        String nodeResponse = response.getBody();
        String body = "Spring received: " + value + "\nNode response: " + nodeResponse;
        return ResponseEntity.ok(body);
    }
}

4. Run the Node.js “plus-one” Service in Docker

Ensure Docker is installed and running on your machine.

Execute:

docker run -p 5000:5000 siddharth67/node-service:v1

You should see output similar to:

> node app.js
HOSTNAME is 6dceae5489

4.1 Test the Node.js Service

In a browser or via curl:

curl http://localhost:5000/plusone/999

Expected response: 1000

5. Run and Test the Spring Boot Application

Start the Spring Boot service:

• In your IDE: Run As → Spring Boot App

• Or via Maven:

  mvn spring-boot:run
  

By default, it listens on port 8080. Test the endpoints:

Sample Responses

1. Welcome:

   $ curl http://localhost:8080/
   Kubernetes DevSecOps
   

2. Compare:

   $ curl http://localhost:8080/compare/55
   Greater than 50
   

3. Increment:

   $ curl http://localhost:8080/increment/55
   Spring received: 55
   Node response: 56
   

In your IDE console, look for:

... INFO ... NumericController     : Value received in request: 55

In the Docker container logs you’ll see:

Value Received = 55

6. Next Steps

Before deploying to Kubernetes:

1. Switch baseURL back to

   private static final String baseURL = "http://node-service:5000/plusone";
   

2. Configure a Maven build and set up a Jenkins pipeline to automate the Spring Boot deployment.

Links and References

• Spring Boot Reference Guide
• Docker Documentation
• Maven POM Reference