How to use this image

All examples in this guide use the public image. If you’ve mirrored the repository for your own use (for example, to your Docker Hub namespace), update your commands to reference the mirrored image instead of the public one.

For example:

• Public image: dhi.io/<repository>:<tag>
• Mirrored image: <your-namespace>/dhi-<repository>:<tag>

For the examples, you must first use docker login dhi.io to authenticate to the registry to pull the images.

Start a RabbitMQ server instance

RabbitMQ stores data based on what it calls the "Node Name", which defaults to the hostname. When running a container in Docker, you should specify -h or --hostname explicitly for each daemon so that you don't get a random hostname and can keep track of our data. For example, run the following command and replace <tag> with the image variant you want to run.

$ docker run -d --hostname my-rabbit --name some-rabbit dhi.io/rabbitmq:<tag>

This starts a RabbitMQ server instance in a container named some-rabbit with the hostname my-rabbit.

Common RabbitMQ use cases

Configure using environment variables

The following example shows how to use environment variables to set the default user and password for RabbitMQ.

$ docker run -d --hostname my-rabbit --name some-rabbit -e RABBITMQ_DEFAULT_USER=user -e RABBITMQ_DEFAULT_PASS=password dhi.io/rabbitmq:<tag>

This will create a new user user with password password and grant that user administrative privileges.

For a list of environment variables supported by RabbitMQ itself, see the official documentation for Environment Variables⁠⁠

Enable management plugin

The management plugin provides a web-based UI for monitoring and administering your RabbitMQ server. You can use Docker Compose with a volume mount:

services:
  rabbitmq:
    image: dhi.io/rabbitmq:<tag>
    hostname: my-rabbit
    ports:
      - "5672:5672"
      - "15672:15672"
    environment:
      RABBITMQ_DEFAULT_USER: user
      RABBITMQ_DEFAULT_PASS: password
    volumes:
      - ./enabled_plugins:/etc/rabbitmq/enabled_plugins:ro

Create an enabled_plugins file:

$ echo '[rabbitmq_management].' > enabled_plugins

Run Docker Compose:

$ docker compose up -d

Then go to http://localhost:15672 in a browser and use user / password to log in.

Configure using a config file

You can provide custom configuration using a bind-mounted config file:

$ docker run -d --name some-rabbit -v /path/to/rabbitmq.conf:/etc/rabbitmq/rabbitmq.conf:ro dhi.io/rabbitmq:<tag>

Example rabbitmq.conf file:

default_user = myuser
default_pass = mypassword
vm_memory_high_watermark.relative = 0.4

For more details on configuring RabbitMQ, see the official documentation for Configuration File(s)⁠.

Use RabbitMQ in Kubernetes

To use the RabbitMQ hardened image in Kubernetes, set up authentication⁠ and update your Kubernetes deployment. For example, in your rabbitmq.yaml file, replace the image reference in the container spec. In the following example, replace <tag> with the desired tag.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: rabbitmq
  namespace: <kubernetes-namespace>
spec:
  template:
    spec:
      containers:
        - name: rabbitmq
          image: dhi.io/rabbitmq:<tag>
          ports:
          - containerPort: 5672
      imagePullSecrets:
        - name: <your-registry-secret>

Then apply the manifest to your Kubernetes cluster.

$ kubectl apply -n <kubernetes-namespace> -f rabbitmq.yaml

Non-hardened images vs. Docker Hardened Images

Key differences

Why no shell or package manager?

Docker Hardened Images prioritize security through minimalism:

• Reduced attack surface: Fewer binaries mean fewer potential vulnerabilities
• Immutable infrastructure: Runtime containers shouldn't be modified after deployment
• Compliance ready: Meets strict security requirements for regulated environments

The hardened images intended for runtime don't contain a shell nor any tools for debugging. Common debugging methods for applications built with Docker Hardened Images include:

• Docker Debug⁠ to attach to containers
• Docker's Image Mount feature to mount debugging tools
• Ecosystem-specific debugging approaches

Docker Debug provides a shell, common debugging tools, and lets you install other tools in an ephemeral, writable layer that only exists during the debugging session.

For example, you can use Docker Debug:

docker debug <image-name>

or mount debugging tools with the image mount feature:

docker run --rm -it --pid container:my-container \
  --mount=type=image,source=dhi.io/busybox,destination=/dbg,ro \
  dhi.io/<image-name>:<tag> /dbg/bin/sh

Image variants

Docker Hardened Images come in different variants depending on their intended use.

• Runtime variants are designed to run your application in production. These images are intended to be used either directly or as the FROM image in the final stage of a multi-stage build. These images typically:

  • Run as the nonroot user
  • Do not include a shell or a package manager
  • Contain only the minimal set of libraries needed to run the app

• Build-time variants typically include dev in the variant name and are intended for use in the first stage of a multi-stage Dockerfile. These images typically:

  • Run as the root user
  • Include a shell and package manager
  • Are used to build or compile applications

• Compat variants support more seamless usage of DHI as a drop-in replacement for upstream images, particularly for circumstances that the ultra-minimal runtime variant may not fully support. These images typically:

  • Run as the nonroot user
  • Improve compatibility with upstream helm charts
  • Include optional tools that are critical for certain use-cases

• FIPS variants include fips in the variant name and tag. They come in both runtime and build-time variants. These variants use cryptographic modules that have been validated under FIPS 140, a U.S. government standard for secure cryptographic operations. For example, usage of MD5 fails in FIPS variants.

Migrate to a Docker Hardened Image

Switching to the hardened RabbitMQ image requires minimal changes for basic use cases. However, be aware that the hardened image uses rabbitmq-server as its entry point, while the standard image uses docker-entrypoint.sh, so ensure that your commands and arguments are compatible.

Migration steps

1. Replace the image reference in your Docker run command or Compose file.

2. All your existing environment variables, volume mounts, and network settings remain the same.

Troubleshooting migration

The following are common issues that you may encounter during migration.

General debugging

The hardened images intended for runtime don't contain a shell nor any tools for debugging. The recommended method for debugging applications built with Docker Hardened Images is to use Docker Debug⁠ to attach to these containers. Docker Debug provides a shell, common debugging tools, and lets you install other tools in an ephemeral, writable layer that only exists during the debugging session.

Permissions

By default image variants intended for runtime, run as the nonroot user. Ensure that necessary files and directories are accessible to the nonroot user. You may need to copy files to different directories or change permissions so your application running as the nonroot user can access them.

Privileged ports

Non-dev hardened images run as a nonroot user by default. As a result, applications in these images can't bind to privileged ports (below 1024) when running in Kubernetes or in Docker Engine versions older than 20.10. To avoid issues, configure your application to listen on port 1025 or higher inside the container, even if you map it to a lower port on the host. For example, docker run -p 80:8080 my-image will work because the port inside the container is 8080, and docker run -p 80:81 my-image won't work because the port inside the container is 81.

No shell

By default, image variants intended for runtime don't contain a shell. Use dev images in build stages to run shell commands and then copy any necessary artifacts into the runtime stage. In addition, use Docker Debug to debug containers with no shell.

Entry point

Docker Hardened Images may have different entry points than images such as Docker Official Images. Use docker inspect to inspect entry points for Docker Hardened Images and update your Dockerfile if necessary.