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.

What's included in this Velero image

This Docker Hardened Velero image includes :

• velero: You can use it to install the Velero server in a Kubernetes cluster, and to create, manage, and restore backups. The same binary also runs as the Velero server inside the cluster.
• velero-restore-helper: A helper tool that Velero invokes automatically when needed.

Plugins for storage providers

Velero requires a storage backend to store backups. Each plugin image adds support for a specific provider, and you must specify the appropriate plugin when installing Velero (for example, with velero install). Before using a plugin image, you must mirror its DHI repository in addition to the Velero DHI repository.

Available hardened plugin images include:

• Velero Plugin for AWS: Adds support for Amazon S3 and S3-compatible storage (including MinIO).
• Velero Plugin for GCP: Adds support for Google Cloud Storage.
• Velero Plugin for Azure: Adds support for Azure Blob Storage.

Install Velero using this image

Unlike other Docker Hardened Images, you don’t run the Velero server directly with docker run. Instead, you use the Velero CLI to install the server into your Kubernetes cluster. The velero install command deploys the Velero server into the cluster using the specified images.

The velero image contains the velero binary, which acts as both the CLI and the server runtime. When you run velero install with this image, the CLI runs locally and deploys the same hardened image as the server inside your cluster.

The following example installs Velero with the AWS plugin. It assumes you already have a MinIO server running in the velero namespace with a bucket named velero.

docker run -it --rm \
  -v $(pwd)/aws-minio-credentials.txt:/etc/aws-minio-credentials.txt \
  -v $(pwd)/kube/config:/etc/kube-config \
  dhi.io/velero:<tag> \
  velero install \
    --image dhi.io/velero:<tag> \
    --plugins dhi.io/velero-plugin-for-aws:<tag> \
    --provider aws \
    --bucket velero \
    --secret-file /etc/aws-minio-credentials.txt \
    --use-volume-snapshots=false \
    --backup-location-config region=minio,s3ForcePathStyle=true,s3Url=http://minio.velero.svc:9000 \
    --kubeconfig /etc/kube-config

Common Velero use cases

In addition to using this image to install Velero, you can use this image to run velero commands, such as backup and restore. For more details about these commands, see the upstream docs at https://velero.io/docs/main/⁠.

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

The Velero Docker Hardened Image is available as dev, runtime, and FIPS variants.

• 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. 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

Migrate to a Docker Hardened Image

Switching to the hardened Velero image does not require any special changes. You can use it as a drop-in replacement for the standard Velero (velero/velero) image in your existing workflows and configurations.

Migration steps

1. Update your image reference. Replace the image reference in your Docker run command or Compose file:
   • From: velero/velero:<tag>
   • To: dhi.io/velero:<tag>
2. No configuration changes needed. All your existing environment variables, volume mounts, and network settings remain the same.

General migration considerations

While the Velero-specific configuration requires no changes, be aware of these general differences in Docker Hardened Images:

Troubleshoot 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.

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.