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/yet-another-cloudwatch-exporter:<tag>
• Mirrored image: <your-namespace>/dhi-yet-another-cloudwatch-exporter:<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 yet-another-cloudwatch-exporter image

This image contains YACE (yace), a Prometheus exporter for AWS CloudWatch that auto-discovers AWS resources via tags and exposes their metrics on port 5000. The image ships with an example EC2 discovery configuration at /etc/yace/config.yml so the container starts without requiring an externally mounted config file. AWS credentials are required at runtime to connect to CloudWatch — supply them via IRSA, environment variables, or a mounted credentials file as described in the Authentication section⁠ below.

Run the yet-another-cloudwatch-exporter container

Run the following command, replacing <tag> with the image variant you want to use. AWS credentials must be available in the container's environment.

docker run -d --name yace -p 5000:5000 \
  -e AWS_REGION=us-east-1 \
  -e AWS_ACCESS_KEY_ID=<your-key-id> \
  -e AWS_SECRET_ACCESS_KEY=<your-secret-key> \
  dhi.io/yet-another-cloudwatch-exporter:<tag>

Once running, Prometheus metrics are available at http://localhost:5000/metrics.

To inspect available CLI flags, run:

docker run --rm dhi.io/yet-another-cloudwatch-exporter:<tag> --help

AWS credentials

YACE uses the AWS SDK for Go default credential chain⁠. The following methods are all supported:

• IRSA (recommended for Kubernetes) — annotate the pod's service account with an IAM role ARN. No additional environment variables are needed.
• Environment variables — set AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and AWS_REGION (or AWS_DEFAULT_REGION).
• Shared credentials file — mount ~/.aws/credentials into the container at /home/nonroot/.aws/credentials (the runtime image runs as the nonroot user).

The IAM policy attached to the credentials must grant the CloudWatch and resource-tagging permissions YACE needs, with additional permissions required per namespace. See the upstream authentication docs⁠ for the full list.

Use a custom configuration file

The image ships a default EC2 discovery config at /etc/yace/config.yml. To use your own configuration, mount it over that path:

docker run -d --name yace -p 5000:5000 \
  -e AWS_REGION=us-east-1 \
  -e AWS_ACCESS_KEY_ID=<your-key-id> \
  -e AWS_SECRET_ACCESS_KEY=<your-secret-key> \
  -v $(pwd)/yace-config.yml:/etc/yace/config.yml:ro \
  dhi.io/yet-another-cloudwatch-exporter:<tag>

Refer to the upstream configuration docs⁠ for the full configuration reference.

Docker Compose with Prometheus

The following Compose example runs YACE alongside Prometheus. The prometheus-init service (using dhi.io/busybox:1) pre-creates the data volume with the correct ownership because the DHI Prometheus image runs as a nonroot user (uid 65532).

services:
  yace:
    image: dhi.io/yet-another-cloudwatch-exporter:<tag>
    environment:
      - AWS_REGION=us-east-1
      - AWS_ACCESS_KEY_ID=<your-key-id>
      - AWS_SECRET_ACCESS_KEY=<your-secret-key>
    volumes:
      - ./yace-config.yml:/etc/yace/config.yml:ro
    ports:
      - "5000:5000"
    restart: unless-stopped

  prometheus-init:
    image: dhi.io/busybox:1
    user: "0:0"
    volumes:
      - prometheus-data:/var/prometheus
    command: ["chown", "-R", "65532:65532", "/var/prometheus"]
    restart: "no"

  prometheus:
    image: dhi.io/prometheus:<tag>
    ports:
      - "9090:9090"
    volumes:
      - ./prometheus.yml:/etc/prometheus/prometheus.yml:ro
      - prometheus-data:/var/prometheus
    command:
      - '--config.file=/etc/prometheus/prometheus.yml'
      - '--storage.tsdb.path=/var/prometheus'
    depends_on:
      prometheus-init:
        condition: service_completed_successfully
      yace:
        condition: service_started
    restart: unless-stopped

volumes:
  prometheus-data: {}

Create a matching Prometheus scrape configuration:

global:
  scrape_interval: 60s

scrape_configs:
  - job_name: yace
    static_configs:
      - targets: ['yace:5000']

Start the stack:

docker compose up -d

Deploy on Kubernetes with the upstream Helm chart

Install YACE using the official community Helm chart and override the image to use the Docker Hardened Image. Replace <your-registry-secret> with your Kubernetes image pull secret⁠ and <tag> with the desired image tag.

helm install yace oci://ghcr.io/prometheus-community/charts/prometheus-yet-another-cloudwatch-exporter \
  --set "imagePullSecrets[0].name=<your-registry-secret>" \
  --set image.registry=dhi.io \
  --set image.repository=yet-another-cloudwatch-exporter \
  --set image.tag=<tag>

Verify the installation:

kubectl get pods -l app.kubernetes.io/name=prometheus-yet-another-cloudwatch-exporter

For IRSA-based authentication in Kubernetes, annotate the Helm-managed service account with your IAM role ARN:

helm install yace oci://ghcr.io/prometheus-community/charts/prometheus-yet-another-cloudwatch-exporter \
  --set "imagePullSecrets[0].name=<your-registry-secret>" \
  --set image.registry=dhi.io \
  --set image.repository=yet-another-cloudwatch-exporter \
  --set image.tag=<tag> \
  --set serviceAccount.annotations."eks\.amazonaws\.com/role-arn"=arn:aws:iam::<account-id>:role/<role-name>

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.