Prerequisite

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/istio-pilot:<tag>
• Mirrored image: <your-namespace>/dhi-istio-pilot:<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 Istio Pilot image

This Docker Hardened Image includes:

• pilot-discovery binary — the Istio control plane (Istiod) for service discovery and configuration distribution
• mTLS certificate issuance and rotation via built-in CA
• Configuration validation webhook support
• TLS certificates (SSL_CERT_FILE pre-configured)
• CIS benchmark compliance (runtime), FIPS 140 + STIG + CIS compliance (FIPS variant)

Start an Istio Pilot instance

The Istio Pilot image (also known as Istiod) is the control plane component that manages service discovery, configuration distribution, and certificate management for the Istio service mesh. It is designed to run as a Deployment in Kubernetes and requires a Kubernetes environment to function fully.

Run the following command and replace <tag> with the image variant you want to run (for example, 1.31-debian13):

$ docker run --rm dhi.io/istio-pilot:<tag> version

To check the short version:

$ docker run --rm dhi.io/istio-pilot:<tag> version --short

To view all available discovery flags:

$ docker run --rm dhi.io/istio-pilot:<tag> discovery --help

Common Istio Pilot use cases

Start the proxy discovery service

Istiod provides xDS-based service discovery, configuration distribution, and proxy management for all Envoy sidecars in the mesh. In a Kubernetes deployment, it listens on the following ports:

• :15010 — gRPC (plaintext)
• :15012 — gRPC (TLS)
• :15017 — HTTPS (injection and validation webhooks)
• :15014 — HTTP (self-monitoring and metrics)
• :9876 — ControlZ introspection

$ docker run --rm dhi.io/istio-pilot:<tag> discovery --help

Query Pilot metrics and debug endpoints

Use the request subcommand to make HTTP requests to Pilot's internal metrics and debug endpoint while Istiod is running in Kubernetes:

$ docker run --rm dhi.io/istio-pilot:<tag> request --help

Check Istio Pilot version

Verify the version of the Istio Pilot image:

$ docker run --rm dhi.io/istio-pilot:<tag> version

For a concise single-line output:

$ docker run --rm dhi.io/istio-pilot:<tag> version --short

Deploy Istio Pilot in Kubernetes

First follow the authentication instructions for DHI in Kubernetes⁠.

Step 1: Create the namespace

$ kubectl create namespace istio-system

Step 2: Create the image pull secret

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

Step 3: Create the ServiceAccount

$ kubectl create serviceaccount istiod -n istio-system

Step 4: Create the ClusterRole and bindings

Istiod requires cluster-wide permissions to manage service discovery, webhooks, and leader election:

$ kubectl apply -f - <<EOF
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: istiod-clusterrole
rules:
- apiGroups: [""]
  resources: ["namespaces", "configmaps", "endpoints", "pods", "services", "secrets", "nodes", "serviceaccounts"]
  verbs: ["get", "list", "watch", "create", "update", "patch", "delete"]
- apiGroups: ["networking.k8s.io"]
  resources: ["ingresses", "ingressclasses"]
  verbs: ["get", "list", "watch"]
- apiGroups: ["admissionregistration.k8s.io"]
  resources: ["validatingwebhookconfigurations", "mutatingwebhookconfigurations"]
  verbs: ["get", "list", "watch", "create", "update", "patch", "delete"]
- apiGroups: ["apiextensions.k8s.io"]
  resources: ["customresourcedefinitions"]
  verbs: ["get", "list", "watch"]
- apiGroups: ["discovery.k8s.io"]
  resources: ["endpointslices"]
  verbs: ["get", "list", "watch"]
- apiGroups: ["coordination.k8s.io"]
  resources: ["leases"]
  verbs: ["get", "list", "watch", "create", "update", "patch", "delete"]
EOF

$ kubectl create clusterrolebinding istiod-clusterrolebinding \
  --clusterrole=istiod-clusterrole \
  --serviceaccount=istio-system:istiod

Step 5: Create the deployment YAML

Save the following as deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: istiod
  namespace: istio-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: istiod
  template:
    metadata:
      labels:
        app: istiod
    spec:
      serviceAccountName: istiod
      imagePullSecrets:
      - name: dhi-pull-secret
      containers:
      - name: discovery
        image: dhi.io/istio-pilot:<tag>
        command: ["pilot-discovery", "discovery"]
        ports:
        - containerPort: 15010
        - containerPort: 15012
        - containerPort: 15014
        - containerPort: 15017
        securityContext:
          runAsUser: 1337

Step 6: Apply and verify

$ kubectl apply -f deployment.yaml
$ kubectl get pods -n istio-system

Step 7: Confirm Istiod is running

$ kubectl logs -n istio-system -l app=istiod --tail=20

A healthy Istiod will show output similar to:

info    leader election lock obtained: istio-leader
info    Starting ingress status writer
info    leader election lock obtained: istio-gateway-deployment-default
info    ads     XDS: Pushing Services:2 ConnectedEndpoints:0 Version:...

Official Docker image (DOI) vs Docker Hardened Image (DHI)

Image variants

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

Runtime variants are intended for production use. They run as user 1337, contain no shell and no package manager, and are CIS benchmark compliant.

Dev variants are intended for build and development use. They run as root, include bash and apt-get, and are useful for multi-stage builds or debugging workflows.

FIPS variants are intended for environments requiring FIPS 140, STIG, and CIS compliance. They run as user 1337 with no shell or package manager.

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.

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.