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/aws-controllers-k8s-eks-controller:<tag>
• Mirrored image: <your-namespace>/dhi-aws-controllers-k8s-eks-controller:<tag>

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

The controller is a Kubernetes operator, so the image is meant to run inside a cluster. To list its command-line flags, run the image with --help:

$ docker run --rm dhi.io/aws-controllers-k8s-eks-controller:1.26.0-debian13 --help

Install the controller with the upstream Helm chart

You need an Amazon EKS cluster, Helm 3, kubectl access to the cluster, and an IAM role that allows the controller to manage EKS resources in the target AWS Region. The upstream chart is published as an OCI artifact at oci://public.ecr.aws/aws-controllers-k8s/eks-chart. It installs the custom resource definitions, the controller Deployment, the service account, and the RBAC rules. Override its image values to run this image.

$ helm install ack-eks oci://public.ecr.aws/aws-controllers-k8s/eks-chart \
  --version 1.26.0 \
  --namespace ack-system --create-namespace \
  --set image.repository=dhi.io/aws-controllers-k8s-eks-controller \
  --set image.tag=1.26.0-debian13 \
  --set aws.region=us-west-2
$ kubectl --namespace ack-system get pods

The chart installs the custom resource definitions for the eks.services.k8s.aws/v1alpha1 API group. Create custom resources only after the install finishes, because the API server rejects resources of a kind it does not know.

Cluster nodes must be able to pull from dhi.io. If they cannot, create a docker-registry secret for dhi.io in the install namespace and reference it through the chart's image pull settings.

Configure the AWS Region and credentials

The controller must know the AWS Region it manages. Set aws.region in the chart, as shown above, or pass the --aws-region flag or the AWS_REGION environment variable to the container. Without a Region, the controller exits with status 1 and logs AWS region is missing.

The controller reads credentials through the AWS SDK default credential chain. Use one of the following:

• IAM Roles for Service Accounts (IRSA): annotate the controller's service account with the IAM role ARN under the eks.amazonaws.com/role-arn key, using the chart's service account annotation settings.
• EKS Pod Identity: create a Pod Identity association for the controller's service account with aws eks create-pod-identity-association.
• A shared credentials file: mount the file at /.aws/credentials. The image runs as uid 65532 with home /home/nonroot, but /home/nonroot/.aws links to /.aws, so the SDK finds the file at its default path, as it does with upstream's image. To read the file from another path, set AWS_SHARED_CREDENTIALS_FILE to that path. You can also use the chart's credentials secret (aws.credentials.secretName).

IRSA or Pod Identity avoids storing long-lived keys in the cluster. Check the chart's values.yaml for the exact setting names in your chart version.

Ports

• 8080/tcp: Prometheus metrics (--metrics-addr).
• 8081/tcp: health probes on /healthz and /readyz (--healthz-addr).

The webhook server listens on port 9433 only when --enable-webhook-server is set. It is off by default, so the image does not declare that port.

To check the readiness probe from your workstation, forward the port of a controller pod and request /readyz:

$ kubectl --namespace ack-system port-forward pod/<controller-pod> 8081:8081
$ curl -fsS http://127.0.0.1:8081/readyz

curl -f exits with a non-zero status on any response outside the 2xx range.

User and root filesystem

The image runs as uid 65532. The upstream image runs as uid 1000. The upstream chart sets runAsNonRoot and does not set runAsUser, so its default values work without change. If you set runAsUser yourself, use 65532 to match the image.

The chart runs the controller with readOnlyRootFilesystem: true. The image adds no writable paths, so the default chart values need no volume mounts.

Select a FIPS or dev variant

Image variants are identified by their tag. The runtime variants run the controller in production. The other variants are listed below for each distro:

The -fips variants use the Go native FIPS 140-3 module and the OpenSSL FIPS provider, and the image test suite verifies them. The image is marked FIPS-compliant and STIG-certified. To run the FIPS variant, set image.tag to the -fips tag. Keep --reuse-values on the upgrade: without it, Helm resets the release's own settings, such as the credentials secret and the service account's IAM role annotation, to the chart defaults.

$ helm upgrade ack-eks oci://public.ecr.aws/aws-controllers-k8s/eks-chart \
  --version 1.26.0 \
  --namespace ack-system \
  --reuse-values \
  --set image.repository=dhi.io/aws-controllers-k8s-eks-controller \
  --set image.tag=1.26.0-debian13-fips \
  --set aws.region=us-west-2

The -dev variants run as root and include a shell and a package manager. They also keep the unstripped controller binary. Use them for debugging, not for production.

Common ACK EKS controller use cases

Map a workload's service account to an IAM role

A PodIdentityAssociation binds a Kubernetes service account in a namespace of an EKS cluster to an IAM role. The cluster must already exist in EKS, and the role's trust policy must allow the Pod Identity service principal.

apiVersion: eks.services.k8s.aws/v1alpha1
kind: PodIdentityAssociation
metadata:
  name: app-s3-reader
  namespace: default
spec:
  clusterName: my-cluster
  namespace: default
  serviceAccount: app
  roleARN: arn:aws:iam::123456789012:role/app-s3-reader
  tags:
    team: platform

Apply the resource and check its status:

$ kubectl apply -f pod-identity-association.yaml
$ kubectl get podidentityassociations.eks.services.k8s.aws

Non-hardened images vs. Docker Hardened Images

This image differs from the upstream image in two ways that affect deployment:

• User: the image runs as uid 65532 instead of uid 1000. See the user note above. The default chart values work without change.
• Shell and package manager: the runtime variants include neither. Use the -dev variants when you need a shell or a package manager.

Image variants

Docker Hardened Images come in different variants depending on their intended use. Image variants are identified by their tag.

• 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 a 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 tag 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

• 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.

To view the image variants and get more information about them, select the Tags tab for this repository, and then select a tag.

Migrate to a Docker Hardened Image

To migrate your application to a Docker Hardened Image, you must update your Dockerfile. At minimum, you must update the base image in your existing Dockerfile to a Docker Hardened Image. This and a few other common changes are listed in the following table of migration notes.

The following steps outline the general migration process.

1. Find hardened images for your app.

   A hardened image may have several variants. Inspect the image tags and find the image variant that meets your needs.

2. Update the base image in your Dockerfile.

   Update the base image in your application's Dockerfile to the hardened image you found in the previous step. For framework images, this is typically going to be an image tagged as dev because it has the tools needed to install packages and dependencies.

3. For multi-stage Dockerfiles, update the runtime image in your Dockerfile.

   To ensure that your final image is as minimal as possible, you should use a multi-stage build. All stages in your Dockerfile should use a hardened image. While intermediary stages will typically use images tagged as dev, your final runtime stage should use a non-dev image variant.

4. Install additional packages

   Docker Hardened Images contain minimal packages in order to reduce the potential attack surface. You may need to install additional packages in your Dockerfile. Inspect the image variants to identify which packages are already installed.

   Only images tagged as dev typically have package managers. You should use a multi-stage Dockerfile to install the packages. Install the packages in the build stage that uses a dev image. Then, if needed, copy any necessary artifacts to the runtime stage that uses a non-dev image.

   For Alpine-based images, you can use apk to install packages. For Debian-based images, you can use apt-get to install packages.

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.