The best way to run Spring Boot services!

Install the pack utility. Check this guide for the instructions.

Edit pom.xml:

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <configuration>
                <image>
		    <name>paketo-maven</name>
                    <builder>bellsoft/buildpacks.builder:musl</builder>
                </image>
            </configuration>
        </plugin>
    </plugins>
</build>

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

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

Build the image with Maven: mvn spring-boot:build-image

Launch the container: docker run paketo-maven

Install the pack utility. Check this guide for the instructions.

Edit pom.xml:

plugins {
	id 'java'
	id 'org.springframework.boot' version '3.0.6'
	id 'io.spring.dependency-management' version '1.1.0'
}

dependencies {
	implementation 'org.springframework.boot:spring-boot-starter'
	testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

bootBuildImage {
	imageName = "paketo-gradle"
	builder = "bellsoft/buildpacks.builder:musl"
}

Build the image with Maven: gradle bootBuildImage

Launch the container: docker run paketo-gradle

Install the pack utility. Check this guide for the instructions.

Edit pom.xml:

plugins {
	java
	id("org.springframework.boot") version "3.0.6"
	id("io.spring.dependency-management") version "1.1.0"
}

dependencies {
	implementation("org.springframework.boot:spring-boot-starter")
	testImplementation("org.springframework.boot:spring-boot-starter-test")
}

tasks.bootBuildImage {
	imageName.set("paketo-gradle-kotlin")
	builder.set("bellsoft/buildpacks.builder:musl")
}

Build the image with Maven: gradle bootBuildImage

Launch the container: docker run paketo-gradle-kotlin

If you don't have a project ready for testing, visit Spring Initilizr and create it there. It will contain all the dependencies, so all you will have to do is add the configuration for bootBuildImage, or run pack with required parameters.

In this example, we use Spring Petclinic as the application we put into the buildpack. You can use your app instead when you are ready.

The following code will return a copy of Petclinic from the most recent commit at the time of writing of this tutorial:

curl -L https://github.com/spring-projects/spring-petclinic/archive/a5cbb8505a1df3c348c06607933a07fc8c87c222.zip --output spring-petclinic-main.zip

unzip ./spring-petclinic-main.zip

mv ./spring-petclinic-a5cbb8505a1df3c348c06607933a07fc8c87c222 ./spring-petclinic-main

cd ./spring-petclinic-main && ./mvnw package

This is the list of useful Docker commands that may help.

• To check how much disk space the image takes, run

  docker image ls demo-app

  The result should be similar to the output below:

  REPOSITORY   TAG       IMAGE ID       CREATED        SIZE
  demo-app     latest    24ac5ac02b2a   43 years ago   152MB

• To find out the OS version in package, run

  docker run --rm -it --entrypoint /bin/cat demo-app /etc/os-release

  For our image, the result should be:

  NAME="BellSoft Alpaquita Linux Stream"
  ID=alpaquita
  ID_LIKE=alpine
  VERSION_ID=23
  PRETTY_NAME="BellSoft Alpaquita Linux Stream 23 (musl)"
  HOME_URL="https://bell-sw.com/"
  BUG_REPORT_URL="https://bell-sw.com/support/"
  LIBC_TYPE=musl
  

• Last but not least, let’s see what is inside the container built by Paketo without unpacking it. Run the following command (which is built into the Paketo):

  pack inspect demo-app

  If you used the Petclinic app, the result will likely be the following:

  Inspecting image: demo-app
  
  REMOTE:
  (not present)
  
  LOCAL:
  
  Stack: io.buildpacks.stacks.alpaquita-musl
  
  Base Image:
    Reference: 116beca369efbba0a9dfff7361b7ce7c302cac684904ddc365e7d6ba82505f58
    Top Layer: sha256:7caddaa60b9c1ca8f0dfa5882f96239493ef54e94e5e8c47ddf84745186eff35
  
  Run Images:
    bellsoft/buildpacks.alpaquita-run:musl
  
  Buildpacks:
    ID                                      VERSION        HOMEPAGE
    bellsoft/buildpacks/liberica            1.0.0          https://github.com/bell-sw/buildpacks/liberica
    paketo-buildpacks/syft                  1.26.0         https://github.com/paketo-buildpacks/syft
    paketo-buildpacks/gradle                6.11.0         https://github.com/paketo-buildpacks/gradle
    paketo-buildpacks/maven                 6.13.0         https://github.com/paketo-buildpacks/maven
    paketo-buildpacks/executable-jar        6.6.1          https://github.com/paketo-buildpacks/executable-jar
    paketo-buildpacks/spring-boot           5.23.0         https://github.com/paketo-buildpacks/spring-boot
  
  Processes:
    TYPE                  SHELL        COMMAND        ARGS                                              WORK DIR
    web (default)                      java           -jar /workspace/spring-petclinic-3.0.0.jar        /workspace
    executable-jar                     java           -jar /workspace/spring-petclinic-3.0.0.jar        /workspace
    task                               java           -jar /workspace/spring-petclinic-3.0.0.jar        /workspace