Creating, running and deploying Spring microservices in 5 minutes

Creating, running and deploying Spring microservices in 5 minutes

Spring developers looking for a quick way to create a microservice which can be deployed on Bluemix should check out the latest version of the Bluemix Developer CLI plugin which now has the option to create a Spring microservice. Just to clarify things right at the start, this isn’t an alternative to Spring Initializer, it’s a way to create a basic microservice which can be optionally bound to Bluemix services and deployed using the CLI.

In this post I am going to show how the Bluemix CLI can be used to generate a Spring microservice, provision and bind services to it and finally deploy to Bluemix. We’ll also take a look at the code that has been generated and how that provides a great starting point for you to begin adding your own code.

Generating the code

If you haven’t already done so, then you’ll need to follow the instructions for installing the Bluemix Developer CLI plugin if you want to try things out for yourself. A Spring microservice can be generated using the CLI as shown below with the generated code being put into a folder under the current directory.

spring $bx dev create

? Select a pattern:                       

1. Web App

2. Mobile App

3. Backend for Frontend

4. Microservice

5. MFP

Enter a number> 4

? Select a starter:

1. Basic

Enter a number> 1

? Select a language:

1. Java - MicroProfile / Java EE

2. Node

3. Python

4. Java - Spring Framework

Enter a number> 4

? Enter a name for your project> springmsdemo                            

? Enter a hostname for your project> springmsdemo

? Do you want to add services to your project? [y/n]> y

? Select a service:

1. Cloudant NoSQL Database

2. Object Storage

Enter a number> 1

? Select a service plan:              

1. Lite

2. Standard

3. Dedicated Hardware

Enter a number> 1

Successfully added service to project.              

? Do you want to add another service? [y/n]> n

The project, springmsdemo, has been successfully saved into the current directory. OK

Before carrying on, let’s look at what we’ve just selected and what has been generated. The first couple of selections establish that we want a microservice and it’s going to use Spring. Things get interesting when we’re presented with the service options. If you pick a service, in this case Cloudant, then not only is code generated to bind to that service but it is also provisioned ready for use.

Other files that are generated will be used when running your application locally in a docker container. The README is a good place to start as it will provide an overview on what has been generated as well as more information about the services that were selected.

Running the microservice

The CLI is then used to build and run the microservice locally. The build stage will create a docker container that provides the necessary tools to build the microservice, a second container is then used to run the built container.

springmsdemo $bx dev build

Deleting the container named 'bx-dev-springmsdemo-tools' ...

Creating image bx-dev-java-maven-tools based on Dockerfile-tools...

Image will have user added

OK                   

Creating a container named 'bx-dev-springmsdemo-tools' from that image...

OK

Starting the 'bx-dev-springmsdemo-tools' container...

OK

Building the project in the current directory started at Wed Aug 23 13:49:37 2017

OK                   

Stopping the 'springmsdemo' container...

The 'springmsdemo' container was not found

Stopping the 'bx-dev-springmsdemo-tools' container...

OK

springmsdemo $bx dev run

Stopping the 'springmsdemo' container...

The 'springmsdemo' container was not found

Creating image springmsdemo based on Dockerfile...

OK                   

Creating a container named 'springmsdemo' from that image...

OK

Starting the 'springmsdemo' container...

OK

Executing run command started at Wed Aug 23 13:50:17 2017

2017-08-23 12:50:22.167  INFO 17 --- [           main] application.SBApplication                : Starting SBApplication v1.0-SNAPSHOT on d6e23df14534 with PID 17 (/project/springmsdemo-1.0-SNAPSHOT.jar started by root in /project)

...

(output snipped)

You can now test your microservice locally by going to http://localhost:8080/v1/cloudant.

The really nice thing is that although the list of databases is empty, the list has been read from the Cloudant service instance that was provisioned earlier.

<br>
@RestController<br>
public class Example {<p></p>
<p>  @Autowired @ServiceName(name="springmsdemo-cloudantNoSQLDB-4dce")<br>
  private CloudantClient client;</p>
<p>  @RequestMapping("v1/")<br>
  public @ResponseBody ResponseEntity<String> example() {<br>
    List<String> list = new ArrayList<>();<br>
    //return a simple list of strings<br>
    list.add("Some data");<br>
    return new ResponseEntity<String>(list.toString(), HttpStatus.OK);<br>
  }</p>
<p>  @RequestMapping("v1/cloudant")<br>
  public @ResponseBody ResponseEntity<String> cloudant(){<br>
      List<String> list = new ArrayList<>();<br>
      try {<br>
          list = client.getAllDbs();<br>
      } catch (NullPointerException e) {<br>
          return new ResponseEntity<String>("Server Error", HttpStatus.INTERNAL_SERVER_ERROR);<br>
      }<br>
      return new ResponseEntity<String>("Available databases : " + list.toString(), HttpStatus.OK);<br>
  }</p>
<p>}<br>
</p>

Deploying to bluemix

The final step is to deploy the microservice to Bluemix. Simply type ‘bx dev deploy‘ on the command line and that’s it. You can then view the microservice in the Bluemix console (along with the service that was created).

This post has shown how to use the Bluemix CLI Developer plug-in to create a Spring microservice bound to a Cloudant database, build and run it locally then finally deploy it Bluemix – all in under 5 minutes !