How to use this image

Before you can use any Docker Hardened Image, you must mirror the image repository from the catalog to your organization. To mirror the repository, select either Mirror to repository or View in repository > Mirror to repository, and then follow the on-screen instructions.

What's included in this Cilium Operator Generic Hardened Image

This Docker Hardened Cilium Operator Generic image includes the operator component of Cilium. The operator manages cluster-wide duties such as identity allocation, network policy coordination, and service load balancing. It provides centralized control plane functionality for Cilium deployments, ensuring consistent policy application and resource management across all nodes in the cluster.

Start a Cilium Operator Generic image

docker run --rm -it <your-namespace>/dhi-cilium-operator-generic:<tag> --help

Common use cases

Install Cilium with Cilium Operator Generic using Helm

You can install Cilium with Cilium Operator Generic using the official Helm chart and replace the operator image. Replace <your-namespace> with your organization's namespace, <your-registry-secret> with your Kubernetes image pull secret⁠, and <tag> with the desired image tag.

helm repo add cilium https://helm.cilium.io/
helm repo update

helm upgrade --install cilium cilium/cilium \
  --namespace kube-system \
  --set operator.enabled=true \
  --set "imagePullSecrets[0].name=<your-registry-secret>" \
  --set operator.image.override="<IMAGE_REPOSITORY>:<IMAGE_TAG>"

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=<your-namespace>/dhi-busybox,destination=/dbg,ro \
  <your-namespace>/dhi-cilium-operator-generic:<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

Migrate to a Docker Hardened Image

Switching to the hardened Cilium Operator Generic image does not require any special changes. You can use it as a drop-in replacement for the standard Cilium Operator Generic (cilium/cilium-operator-generic) image in your existing workflows and configurations. Note that the entry point for the hardened image may differ from the standard image, so ensure that your commands and arguments are compatible.

Migration steps

1. Update your image reference.

   Replace the image reference in your Docker run command or Compose file, for example:

   • From: cilium/cilium-operator-generic:<tag>
   • To: <your-namespace>/dhi-cilium-operator-generic:<tag>

2. All your existing command-line arguments, environment variables, port mappings, and network settings remain the same.

3. Test your migration and use the troubleshooting tips below if you encounter any issues.

Troubleshooting 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.