Chainguard Image for maven

Minimal image with Maven build system.

Chainguard Images are regularly-updated, minimal container images with low-to-zero CVEs.

Download this Image

This image is available on cgr.dev:

docker pull cgr.dev/ORGANIZATION/maven:latest

Be sure to replace the ORGANIZATION placeholder with the name used for your organization's private repository within the Chainguard registry.

Using Maven

Chainguard Maven images come with different versions of OpenJDK, ensure you choose the correct image tag for your application needs. In these examples we will use a Chainguard Maven image based on OpenJDK 17.

Check the maven version

docker run --rm --platform=linux/amd64 cgr.dev/chainguard/maven:openjdk-17 --version

Examples

SpringBoot

Visit https://start.spring.io

Select the following options:

1. Project: select Maven Project
2. Spring Boot: latest GA version, e.g. 2.7.5
3. Project Metadata: populate your application details
4. Packaging: select your packaging. For this demo, we'll use jar
5. Java: select Java version, e.g. 17 that matches the OpenJDK image version we are building with
6. Dependencies: choose your dependencies, e.g. Spring Web
7. Generate: Hit that generate button!

Go to your downloaded zip file, unzip

mkdir ~/chainguard-sb
cd chainguard-sb
mv ~/Downloads/demo.zip .
unzip demo.zip
cd demo

You now have your generated Spring Boot application souce code. Now let's build it.

docker run --platform=linux/amd64 --rm -v ${PWD}:/home/build cgr.dev/chainguard/maven:openjdk-17 clean install

Check to see your compiled jar file

find target -name "*.jar"

You should see...

target/demo-0.0.1-SNAPSHOT.jar

Let's run the application using the Chainguard OpenJDK JRE image. Note there's a few things happening here and this is just for test purposes, see section below for more real world scenarios.

Choose the Chainguard OpenJDK JRE image tag that matches your application's Java version selected when generating your Spring Boot application above.

docker run --platform=linux/amd64 --rm -p 8080:8080 -v ${PWD}/target:/app/ cgr.dev/chainguard/jre:openjdk-17 -jar /app/demo-0.0.1-SNAPSHOT.jar

Now visit the Spring Boot Application in your browser using the same port mapped in the docker command above.

e.g http://localhost:8080/

Note this is the expected Spring Whitelabel error page.

Multistage Dockerfile

The steps above are useful to test Chainguard images however, we can now create a multistage Dockerfile that will build a smaller image to run our demo application.

First create a .dockerignore file so we don't copy the generated maven ./target folder from the steps above into the multistage docker build. This helps avoid any permission errors during the build.

cat <<EOF >>.dockerignore
target/
EOF

Next create the multistage Dockerfile

cat <<EOF >>Dockerfile
FROM cgr.dev/chainguard/maven:openjdk-17

WORKDIR /home/build

COPY . ./

RUN mvn install

FROM cgr.dev/chainguard/jre:openjdk-17

COPY --from=0 /home/build/target/demo-*.jar /app/demo.jar

CMD ["-jar", "/app/demo.jar"]
EOF

Build your application image

docker build --platform=linux/amd64 -t my-chainguard-springboot-app .

Now run your application

docker run --platform=linux/amd64 --rm -p 8080:8080 my-chainguard-springboot-app

Again visit the Spring Boot Whitelabel page in your browser

e.g. http://localhost:8080/

What's inside?

Now let's take a closer look at your newly built image.

Check the size of your image, as this is based on Chainguard images it will only contain the Linux packages required to run your application. The reduces the number of packages that can be affected by CVEs.

docker images | grep my-chainguard-springboot-app

You can also check for vulnerabilities using your favorite scanner.

Contact Support

If you have a Zendesk account (typically set up for you by your Customer Success Manager) you can reach out to Chainguard's Customer Success team through our Zendesk portal.

What are Chainguard Images?

Chainguard Images are a collection of container images designed for security and minimalism.

Many Chainguard Images are distroless; they contain only an open-source application and its runtime dependencies. These images do not even contain a shell or package manager. Chainguard Images are built with Wolfi, our Linux undistro designed to produce container images that meet the requirements of a secure software supply chain.

The main features of Chainguard Images include:

• Minimal design, with no unnecessary software bloat
• Automated nightly builds to ensure Images are completely up-to-date and contain all available security patches
• High quality build-time SBOMs (software bills of materials) attesting the provenance of all artifacts within the Image
• Verifiable signatures provided by Sigstore
• Reproducible builds with Cosign and apko (read more about reproducibility)

-dev Variants

As mentioned previously, Chainguard’s distroless Images have no shell or package manager by default. This is great for security, but sometimes you need these things, especially in builder images. For those cases, most (but not all) Chainguard Images come paired with a -dev variant which does include a shell and package manager.

Although the -dev image variants have similar security features as their distroless versions, such as complete SBOMs and signatures, they feature additional software that is typically not necessary in production environments. The general recommendation is to use the -dev variants only to build the application and then copy all application artifacts into a distroless image, which will result in a final container image that has a minimal attack surface and won’t allow package installations or logins.

That being said, it’s worth noting that -dev variants of Chainguard Images are completely fine to run in production environments. After all, the -dev variants are still more secure than many popular container images based on fully-featured operating systems such as Debian and Ubuntu since they carry less software, follow a more frequent patch cadence, and offer attestations for what they include.

Learn More

To better understand how to work with Chainguard Images, we encourage you to visit Chainguard Academy, our documentation and education platform.