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-iam-controller:1
• Mirrored image: <your-namespace>/dhi-aws-controllers-k8s-iam-controller:1

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

The AWS Controllers for Kubernetes (ACK) IAM controller is a Kubernetes operator. It runs inside a cluster, reconciles AWS IAM resources that you declare as Kubernetes custom resources, and calls AWS with the credentials you provide. The image's entrypoint is the controller binary, /bin/controller. Upstream documentation for the custom resources and the IAM setup is at https://github.com/aws-controllers-k8s/iam-controller⁠.

The Debian 13 runtime tag is dhi.io/aws-controllers-k8s-iam-controller:1.12.0-debian13. The Alpine 3.24 runtime tag is dhi.io/aws-controllers-k8s-iam-controller:1.12.0-alpine3.24. The shorter tags 1 and 1.12 point to the Debian 13 runtime image.

Start an AWS Controllers for Kubernetes IAM controller image

The entrypoint is /bin/controller, and the image sets no command. Arguments that you pass to docker run are flags for the controller. Runtime tags run as user 65532 and contain no shell.

Basic usage

docker run --rm dhi.io/aws-controllers-k8s-iam-controller:1 --help

The output lists every flag the controller accepts. There is no --version flag.

Configure credentials and the cluster

The controller needs two things at startup:

• Kubernetes access: in-cluster service account configuration when it runs in a pod, or a kubeconfig when it runs outside the cluster.
• AWS credentials from the AWS SDK default credential chain: environment variables, the shared credentials file, or web identity (IAM Roles for Service Accounts, IRSA). The controller calls AWS STS when it starts, so startup fails without credentials.

Common flags

The image exposes 8080/tcp for metrics and 8081/tcp for health probes, served at /healthz and /readyz.

Deploy with Helm

This quick start installs the upstream chart, oci://public.ecr.aws/aws-controllers-k8s/iam-chart version 1.12.0, and points its image at this image. Prerequisites: a Kubernetes cluster, Helm 3.8 or later, and an AWS account with IAM permissions for the resources you manage. The upstream project documents the custom resources and IAM setup at https://github.com/aws-controllers-k8s/iam-controller⁠.

1. Create the namespace and the AWS credentials secret. The chart reads the credentials key of the aws-credentials secret. Write your access key to a shared credentials file first, in the standard [default] profile format.

   kubectl create namespace ack-system
   kubectl -n ack-system create secret generic aws-credentials --from-file=credentials=./credentials
   

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2. If the cluster pulls from dhi.io with credentials, create a pull secret in the same namespace. Skip this step when the pull is anonymous.

   kubectl -n ack-system create secret docker-registry dhi-pull-secret \
     --docker-server=dhi.io --docker-username=<username> --docker-password=<token>
   

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3. Install the chart with this image. Use a runtime tag. The chart sets runAsNonRoot and a read-only root filesystem, and the -dev tags run as root, so the pod is rejected. The chart does not set runAsUser, so the pod runs as the numeric nonroot user 65532 of the image. Add --set image.pullSecrets[0]=dhi-pull-secret when you created the pull secret in the previous step.

   helm install iam-chart oci://public.ecr.aws/aws-controllers-k8s/iam-chart \
     --version 1.12.0 \
     --namespace ack-system \
     --set image.repository=dhi.io/aws-controllers-k8s-iam-controller \
     --set image.tag=1.12.0-debian13 \
     --set aws.region=us-east-1 \
     --set aws.credentials.secretName=aws-credentials
   

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   Use image.tag=1.12.0-alpine3.24 for Alpine 3.24, or a -fips tag from the FIPS section. Replace us-east-1 with the Region where the controller creates resources.

4. Check that the controller is running and healthy.

   kubectl -n ack-system rollout status deployment/iam-chart
   kubectl -n ack-system port-forward deployment/iam-chart 8081:8081
   

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   In a second terminal, curl -s http://localhost:8081/healthz prints ok. The rollout completes when the pod is ready.

5. Optional: reconcile a resource. This creates an IAM role and waits for ACK to report it synced.

   apiVersion: iam.services.k8s.aws/v1alpha1
   kind: Role
   metadata:
     name: dhi-role-example
     namespace: ack-system
   spec:
     name: dhi-role-example
     assumeRolePolicyDocument: '{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Principal":{"Service":"ec2.amazonaws.com"},"Action":"sts:AssumeRole"}]}'
   

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   Use the full resource name role.iam.services.k8s.aws. A bare role resolves to the Kubernetes RBAC Role kind.

   kubectl -n ack-system apply -f role.yaml
   kubectl -n ack-system wait --for=condition=ACK.ResourceSynced=True role.iam.services.k8s.aws/dhi-role-example --timeout=2m
   kubectl -n ack-system delete role.iam.services.k8s.aws dhi-role-example
   

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   Deleting the custom resource deletes the IAM role in AWS.

Non-hardened images vs. Docker Hardened Images

• User: The upstream image runs as user 1000. The runtime and FIPS runtime tags run as user 65532. Change any runAsUser: 1000 in your manifests to 65532. The -dev tags run as root.
• Entrypoint: The entrypoint is /bin/controller, the same as upstream, so you do not need a workaround. On the Alpine tags, /bin/controller is a symlink to /usr/bin/controller. The Debian tags use /usr/bin/controller through the merged /bin directory. Neither layout changes how you run the controller.

FIPS variants

• The -fips and -fips-dev tags build the controller with the FIPS 140 Go cryptographic module (GOFIPS140=v1.0.0). The default runtime setting is fips140=on, so TLS connections to AWS use the FIPS module.
• The FIPS images include the OpenSSL FIPS provider.
• The FIPS runtime tags run as user 65532, the same as the standard runtime tags.

Debian 13 FIPS tags: 1.12.0-debian13-fips (runtime) and 1.12.0-debian13-fips-dev (dev). Alpine 3.24 FIPS tags: 1.12.0-alpine3.24-fips (runtime) and 1.12.0-alpine3.24-fips-dev (dev).

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.