Sonatype Nexus Repository Docker: sonatype/nexus3

A Dockerfile for Sonatype Nexus Repository 3, starting with 3.18 the image is based on the Red Hat Universal Base Image while earlier versions used CentOS.

• Contribution Guidlines
• Running
• Building the Sonatype Nexus Repository image
• Chef Solo for Runtime and Application
• Testing the Dockerfile
• Red Hat Certified Image
• Notes
  • Persistent Data
• Getting Help

Contribution Guidelines

Go read our contribution guidelines to get a bit more familiar with how we would like things to flow.

Running

To run, binding the exposed port 8081 to the host, use:

$ docker run -d -p 8081:8081 --name nexus sonatype/nexus3

When stopping, be sure to allow sufficient time for the databases to fully shut down.

docker stop --time=120 <CONTAINER_NAME>

To test:

$ curl http://localhost:8081/

Building the Sonatype Nexus Repository image

To build a docker image from the Dockerfile you can use this command:

$ docker build --rm=true --tag=sonatype/nexus3 .

The following optional variables can be used when building the image:

• NEXUS_VERSION: Version of the Sonatype Nexus Repository
• NEXUS_DOWNLOAD_URL: Download URL for Sonatype Nexus Repository, alternative to using NEXUS_VERSION to download from Sonatype
• NEXUS_DOWNLOAD_SHA256_HASH: Sha256 checksum for the downloaded Sonatype Nexus Repository archive. Required if NEXUS_VERSION or NEXUS_DOWNLOAD_URL is provided

Chef Solo for Runtime and Application

Chef Solo is used to build out the runtime and application layers of the Docker image. The Chef cookbook being used is available on GitHub at sonatype/chef-nexus-repository-manager.

Testing the Dockerfile

We are using rspec as the test framework. serverspec provides a docker backend (see the method set in the test code) to run the tests inside the docker container, and abstracts away the difference between distributions in the tests (e.g. yum, apt,...).

rspec [--backtrace] spec/Dockerfile_spec.rb

Red Hat Certified Image

A Red Hat certified container image can be created using Dockerfile.rh.ubi which is built to be compliant with Red Hat certification. The image includes additional meta data to comform with Kubernetes and OpenShift standards, a directory with the licenses applicable to the software and a man file for help on how to use the software. It also uses an ENTRYPOINT script the ensure the running user has access to the appropriate permissions for OpenShift 'restricted' SCC.

The Red Hat certified container image is available from the Red Hat Container Catalog and qualified accounts can pull it from registry.connect.redhat.com.

Other Red Hat Images

In addition to the Universal Base Image, we can build images based on:

• Red Hat Enterprise Linux: Dockerfile.rh.el
• CentOS: Dockerfile.rh.centos

Alpine Image

An Alpine-based container image can be created using Dockerfile.alpine.java11 This Dockerfile is built to leverage the minimalistic and efficient nature of Alpine Linux, emphasizing fewer dependencies to achieve a cleaner SBOM (Software Bill of Materials) and a stronger security posture.

The Alpine-based container image includes minimal dependencies and uses an ENTRYPOINT script to ensure the application runs with the necessary permissions. It is optimized for rapid deployment and efficient resource usage.

The Alpine-based container image is available from Docker Hub and can be pulled using the following tags:

• sonatype/nexus3:3.XX.y-alpine (runs Java 11)
• sonatype/nexus3:3.XX.y-java11-alpine
• sonatype/nexus3:3.XX.y-java17-alpine

Notes

• Our system requirements should be taken into account when provisioning the Docker container.

• Default user is admin and the uniquely generated password can be found in the admin.password file inside the volume. See Persistent Data for information about the volume.

• It can take some time (2-3 minutes) for the service to launch in a new container. You can tail the log to determine once Nexus is ready:

$ docker logs -f nexus

• Installation of Nexus is to /opt/sonatype/nexus.

• A persistent directory, /nexus-data, is used for configuration, logs, and storage. This directory needs to be writable by the Nexus process, which runs as UID 200.

• There is an environment variable that is being used to pass JVM arguments to the startup script

  • INSTALL4J_ADD_VM_PARAMS, passed to the Install4J startup script. Defaults to -Xms2703m -Xmx2703m -XX:MaxDirectMemorySize=2703m -Djava.util.prefs.userRoot=${NEXUS_DATA}/javaprefs.

  This can be adjusted at runtime:

  $ docker run -d -p 8081:8081 --name nexus -e INSTALL4J_ADD_VM_PARAMS="-Xms2703m -Xmx2703m -XX:MaxDirectMemorySize=2703m -Djava.util.prefs.userRoot=/some-other-dir" sonatype/nexus3
  

  Of particular note, -Djava.util.prefs.userRoot=/some-other-dir can be set to a persistent path, which will maintain the installed Sonatype Nexus Repository License if the container is restarted.

  Be sure to check the memory requirements when deciding how much heap and direct memory to allocate.

• Another environment variable can be used to control the Nexus Context Path

  • NEXUS_CONTEXT, defaults to /

  This can be supplied at runtime:

  $ docker run -d -p 8081:8081 --name nexus -e NEXUS_CONTEXT=nexus sonatype/nexus3
  

Persistent Data

There are two general approaches to handling persistent storage requirements with Docker. See Managing Data in Containers for additional information.

1. Use a docker volume. Since docker volumes are persistent, a volume can be created specifically for this purpose. This is the recommended approach.

$ docker volume create --name nexus-data
$ docker run -d -p 8081:8081 --name nexus -v nexus-data:/nexus-data sonatype/nexus3

2. Mount a host directory as the volume. This is not portable, as it relies on the directory existing with correct permissions on the host. However it can be useful in certain situations where this volume needs to be assigned to certain specific underlying storage.

$ mkdir /some/dir/nexus-data && chown -R 200 /some/dir/nexus-data
$ docker run -d -p 8081:8081 --name nexus -v /some/dir/nexus-data:/nexus-data sonatype/nexus3

Getting Help

Looking to contribute to our Docker image but need some help? There's a few ways to get information or our attention:

• Chat with us on Gitter
• Check out the Nexus3 tag on Stack Overflow
• Check out the Sonatype Nexus Repository User List

License Disclaimer

Sonatype Nexus Repository OSS is distributed with Sencha Ext JS pursuant to a FLOSS Exception agreed upon between Sonatype, Inc. and Sencha Inc. Sencha Ext JS is licensed under GPL v3 and cannot be redistributed as part of a closed source work.