Spring Boot - Maven 3 - CentOS Docker image

This repository contains the sources of the base image for deploying Spring Boot applications as reproducible Docker images. The resulting images can be run either by Docker or using S2I with a prepared s2i.json file.

This image is heavily inspired by the awesome codecentric/springboot-maven3-centos builder image.

Usage

To build a simple springboot-sample-app application using standalone S2I and then run the resulting image with Docker execute:

$ s2i build git://github.com/codecentric/springboot-sample-app skjolber/spring-boot-maven3-jdk8-centos springboot-sample-app
$ docker run -p 8080:8080 springboot-sample-app

Accessing the application:

$ curl 127.0.0.1:8080

Import to Openshift

Add using

$ oc create -n <your project name> -f s2i.json

and remove using

$ oc delete -n <your project name> -f s2i.json 

Secrets

If you are using a private repository, add SSH keys using

$ oc secrets new-sshauth <secret name> --ssh-privatekey=$HOME/.ssh/my_openshift_key_rsa

and remember to use SSH style git repository URLs.

The secret must be manually configured on the generated build (under advanced options), or can be automatically matched against your git repo.

Environment variables

• APP_TARGET (default: '')

  This variable specifies a relative location to your application binary inside the container.

• MVN_ARGS (default: '')

  This variable specifies the arguments for Maven inside the container.

• JAVA_OPTS (default: '')

  Additional Java options, like garbage collector and such.

• XMX (default: '256')

  Java memory

• XMS (default: '32')

  Java memory in megabytes.

• SPRING_ACTIVE_PROFILES (default: 'default')

  Active spring profiles (comma-seperated).

Repository organization

• s2i/bin/

  This folder contains scripts that are run by S2I:

  • assemble

    Is used to restore the build artifacts from the previous built (in case of 'incremental build'), to install the sources into location from where the application will be run and prepare the application for deployment (eg. using maven to build the application etc..)

  • run

    This script is responsible for running a Spring Boot fat jar using java -jar. The image exposes port 8080, so it expects application to listen on port 8080 for incoming request.

  • save-artifacts

    Not currently supported

Contributing

In order to test your changes to this STI image or to the STI scripts, you can use the test/run script. Before that, you have to build the 'candidate' image:

$ docker build -t skjolber/spring-boot-maven3-jdk8-centos-candidate .

After that you can execute ./test/run. You can also use make test to automate this.

Copyright

Released under the Apache License 2.0. See the LICENSE file.

See also

• http://trustmeiamadeveloper.com/2016/03/18/where-is-my-memory-java/
• https://spring.io/blog/2015/12/10/spring-boot-memory-performance