Developing serverless web applications with Azure Spring Cloud

Posted on by Panther

Introduction

Azure Spring Cloud is a fully managed service created to help developers build and run microservices-based applications with less operational overhead. The service is built on top of the Spring Boot framework, which makes it easy to develop Spring-based cloud-native applications. The platform makes it possible for organizations to build cloud-native applications faster without the need for extensive infrastructure provisioning and without sacrificing security and compliance.

In this tutorial, we will develop a serverless web application with Azure Spring Cloud using various components of the platform like Spring Boot, Azure Functions, and Azure API Management. Specifically, we will use serverless computing to minimize the infrastructure overhead and quickly scale up or down to meet user demand.

Prerequisites

  • A Microsoft Azure account
  • A Java Development Kit (JDK)
  • An IDE, preferably IntelliJ IDEA or Eclipse
  • Git
  • Apache Maven

Step 1: Create an Azure Spring Cloud Service Instance

To get started, you will need to create an Azure Spring Cloud service instance. This service instance enables you to deploy, monitor and scale Spring-based microservices. Here are the steps to create an Azure Spring Cloud service instance:

  1. Log in to the Azure Portal and go to the Azure Spring Cloud service page.
  2. Click on the Add button to create a new service instance.
  3. Enter a name for the service instance, select the subscription and resource group, and specify the region where you want to deploy the service.
  4. Select a pricing plan. You can choose from the basic, standard, or premium pricing plans.
  5. Click on the Review + Create button, review your settings, and then click on the Create button.

After creating the Azure Spring Cloud service instance, you will see that a new resource has been added to your Azure subscription.

Step 2: Create a Spring Boot Application

Next, we will create a simple Spring Boot application that will serve as the backend for our serverless web application. Here are the steps to follow:

  1. Open your IDE and create a new Spring Boot project.
  2. Configure the necessary dependencies in the pom.xml file. For this tutorial, we will be using Spring Web and Spring Boot DevTools dependencies. 
<dependencies>
    <dependency>
        <gr

oupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
    </dependency>
</dependencies>
  1. Create a RestController that will handle HTTP requests and responses. In this case, we will create a HelloController that will return a simple greeting message.
@RestController
public class HelloController {

    @GetMapping("/hello")
    public String hello() {
        return "Hello, world!";
    }
}
  1. Run the Spring Boot application locally to test it by using the mvn spring-boot:run command.

Step 3: Package the Application as a JAR File

In order to deploy the application to Azure Spring Cloud, we need to package it as a JAR file. Here are the steps to follow:

  1. Open your command prompt.
  2. Navigate to the root directory of the project.
  3. Run the mvn clean package command. This command will generate a JAR file in the target directory.

Step 4: Deploy the Application to Azure Spring Cloud

The next step is to deploy the application to Azure Spring Cloud. Here are the steps to follow:

  1. Open the Azure Portal.
  2. Go to the Azure Spring Cloud service instance that you created in Step 1.
  3. Click on the App Deployments tab.
  4. Click on the Add button.
  5. Fill in the form with the necessary details to deploy the application.

Here are the fields you need to fill in:

  • App name: Enter the name of your application.
  • JAR file path: Enter the path to the JAR file that you generated in Step 3.
  • Environment variables: If your application requires any environment variables, specify them here.
  • Instance count: Enter the number of instances you want to deploy.
  • Memory per instance: Enter the amount of memory you want to allocate per instance.
  1. Click on the Deploy button.

After deploying the application, you will notice that a new App Deployment has been added to your Azure Spring Cloud service instance.

Step 5: Create an Azure Function

Now, we’ll create an Azure Function that will serve as the frontend for our serverless web application. Here are the steps to follow:

  1. Open the Azure Portal.
  2. Click on the Create a Resource button.
  3. Search for Azure Functions and click on the Create button.
  4. Fill in the necessary details in the form.
  5. Select Node.js as the runtime stack, and choose the Consumption plan as the Hosting Plan.

  6. Click on the Create button.

After creating the Azure Function, you will notice that a new resource has been added to your Azure subscription.

Step 6: Configure the Azure Function

After creating the Azure Function, we need to configure it to connect to our deployed Spring Boot application in Azure Spring Cloud.

  1. Open the Azure Portal.
  2. Go to the Azure Function that you created in Step 5.
  3. Click on the Platform features tab.
  4. Click on the Configuration button.
  5. Click on the Application settings tab.
  6. Click on the New application setting button.
  7. Add a new application setting called SPRING_CLOUD_CONFIG_URI and set its value to the URI of your Azure Spring Cloud configuration server.

For example, if your Azure Spring Cloud configuration server URI is https://my-springcloud-instance.azurespringcloud.net`, the value of theSPRING_CLOUD_CONFIG_URIapplication setting should behttps://my-springcloud-instance.azurespringcloud.net`.

  1. Click on the Save button.

Step 7: Create an Azure API Management

The next step is to create an Azure API Management service. This service will act as the mediator between the frontend Azure Function and the backend Spring Boot application in Azure Spring Cloud.

  1. Open the Azure Portal.
  2. Click on the Create a Resource button.
  3. Search for API Management and click on the Create button.
  4. Fill in the necessary details in the form.
  5. Select the Consumption pricing tier as the Pricing tier.

  6. Click on the Create button.

After creating the Azure API Management service, you will notice that a new resource has been added to your Azure subscription.

Step 8: Configure the Azure API Management

After creating the Azure API Management service, we need to configure it to connect to our

deployed Azure Function and Spring Boot application.

  1. Open the Azure Portal.
  2. Go to the Azure API Management service that you created in Step 7.
  3. Click on the APIs tab.
  4. Click on the Add API button.
  5. Select Function App.
  6. Fill in the necessary details in the form.
  7. Click on the Create button.
  8. Click on the Backend tab.
  9. Specify the backend URL and service name. For the backend URL, specify the URL of the Azure Function that you created in Step 5.

For example, if your Azure Function URL is https://my-function-app.azurewebsites.net/api`, the backend URL should be set tohttps://my-function-app.azurewebsites.net`.

  1. Click on the Save button.

Step 9: Test the Serverless Web Application

Now that we have everything set up, we can test our serverless web application by using the Azure API Management endpoint.

  1. Open a web browser and go to the URL of your Azure API Management service.
  2. Click on the Test tab.
  3. Select the API that you created in Step 8.
  4. Click on the Send button.
  5. You should see a response from the backend Spring Boot application displayed in the response body.

Congratulations! You have successfully developed a serverless web application with Azure Spring Cloud, Azure Functions, and Azure API Management.

Conclusion

In this tutorial, we learned how to develop a serverless web application with Azure Spring Cloud by using various components of the platform like Spring Boot, Azure Functions, and Azure API Management. Specifically, we used serverless computing to minimize the infrastructure overhead and quickly scale up or down to meet user demand. By following the steps outlined in this tutorial, you now have the knowledge to build and deploy serverless web applications that are flexible, scalable, and secure with Azure Spring Cloud.

Related Post