Bootstrap

The detailed steps to bootstrap a custom worker follow.

1. Start a Java project with Spring Boot.

2. In your build file, declare a Maven dependency on "com.decisionbrain:optimserver-worker:4.4.0".

3. In the resources, create a worker.yml file, and declare tasks the worker will be able to perform. See the TaskParameter class in the page for a description of the fields. An example is given below.

   tasks:
   - id: kcoloring
    implementationClassName: com.decisionbrain.kcoloringworker.KColoringTask
    description: This task computes a coloration of a partial Europe map with k colors.
    inputs:
    - name: k
      type: NUMERIC
      description: Number of colors to be used by the coloration.
      required: true
    outputs:
    - name: coloration
      type: JSON
      description: "The coloration found: for each country, the associated color."

4. In the resources, write an application.yml file with the following content. Set the relevant property values.

   spring:
    application:
      name: MyCustomWorker
    rabbitmq:
      username: decisionbrain
      password: decisionbrain
      host: localhost
      port: 5672
   optim-server:
    url: http://localhost:8080/

5. Write a Spring Boot application, with the EnableOptimServerWorker annotation, like this one:

   @EnableOptimServerWorker
   @SpringBootApplication
   public class MyCustomWorker {
      public static void main(String[] args) {
          SpringApplication.run(MyCustomWorker.class, args);
      }
   }

6. Write a Java class for each declared task, and reference it in the worker.yml file. This class has to implement Interface com.decisionbrain.optimserver.worker.api.Task (see page. Here is the skeleton of such a class:

   public class KColoringTask implements Task {
      private static final Logger LOGGER = LoggerFactory.getLogger(KColoringTask.class);
   
      @Override
      public void execute(Parameter input, Parameter output, ExecutionContext context) {
          // TODO: put your optimization code here
      }
   }

7. Now your worker is actually able to handle the declared tasks, it has to be packaged as a docker image to be deployable. First, a jar file should be built, using your favorite build tool (gradle for example). Then a docker image has to be built, using a Dockerfile, and the docker shell client, or any docker plugin for your build tool. Here is a typical Dockerfile:

   FROM <YOUR_BASE_DOCKER_IMAGE_WITH_CPLEX>
   
   ADD build/libs/my-custom-worker.jar my-custom-worker.jar
   
   CMD java $JAVA_OPTS -jar my-custom-worker.jar $PROGRAM_ARGS

Then a docker image can be built using:

docker build .