Spring Boot makes it easy to build microservices. Containers are a standard way to run microservices in production.

This post shows how to develop a spring boot application inside of a docker container using the spring-boot-maven-plugin, the Springsource Toolsuite, docker and fig.

The source is a minimal Spring Boot example from this guide to build a RESTful Web Service with spring boot. The full soucecode can be found on github.

Add a dependecy to spring-loaded to the spring boot maven plugin to reload changed classes inside the docker container. {% highlight xml %} org.springframework.boot spring-boot-maven-plugin org.springframework springloaded 1.2.1.RELEASE {% endhighlight %}

The Dockerfile: {% highlight text %} FROM dockerfile/java:oracle-java8 MAINTAINER philipp.huegelmeyer@ble.de EXPOSE 8080 ENV http_proxy http://httpproxy.service.ble.de:9090 RUN apt-get update RUN DEBIAN_FRONTEND=noninteractive apt-get install -y —force-yes maven RUN mkdir -p /data/spring-rest WORKDIR /data/spring-rest {% endhighlight %}

The fig.yml:

{% highlight text %} web: build: . #environment:

- MAVEN_OPTS=“-javaagent:springloaded-1.2.1.jar -noverify”

ports: - “8080:8080” volumes: - docker-rest:/data/spring-rest command: mvn spring-boot:run {% endhighlight %}

The container can be build with fig build and run it with fig up. Open the maven project inside the springsource toolsuite. Changed classes will be loaded automatically inside the docker container.