Chainguard Container for step-issuer

Minimal container image of step-issuer, a certificate issuer for cert-manager using step certificates CA

Chainguard Containers are regularly-updated, secure-by-default container images.

Download this Container Image

For those with access, this container image is available on cgr.dev:

docker pull cgr.dev/ORGANIZATION/step-issuer:latest

Be sure to replace the ORGANIZATION placeholder with the name used for your organization's private repository within the Chainguard Registry.

Compatibility Notes

The Chainguard step-issuer image is a minimal drop-in replacement for the upstream smallstep/step-issuer. It is fully compatible with the cert-manager framework and the official Helm chart, enabling the issuance of X.509 certificates using a step-ca instance as the backend Certificate Authority. This image is designed to be a minimal, secure alternative that runs as a non-root user. Switching to this image should not require any changes to your existing deployment configuration.

Getting Started

You can deploy this image using the step-issuer Helm chart. Be sure to override the image by setting the following values in a values.yaml file:

image:
  repository: cgr.dev/ORGANIZATION/step-issuer
  tag: "latest"

Be sure to replace the ORGANIZATION placeholder with the name used for your organization's private repository within the Chainguard registry.

Then, deploy the step-issuer helm chart.

helm repo add smallstep https://smallstep.github.io/helm-charts
helm repo update
helm install step-issuer smallstep/step-issuer --namespace step-system --create-namespace --values values.yaml --wait

Using the StepIssuer

Once installed, step-issuer allows cert-manager to request certificates from a step-ca instance.

Here is an example of how to configure a StepClusterIssuer and request a certificate:

1. Create a StepIssuer

apiVersion: cert-manager.step.sm/v1beta1
kind: StepIssuer
metadata:
  name: step-issuer
spec:
  provisioner:
    name: admin
    passwordRef:
      name: step-ca-provisioner-password
      key: password
  caBundle: |
    -----BEGIN CERTIFICATE-----
    MIIB...
    -----END CERTIFICATE-----
  url: https://step-ca.step-system.svc.cluster.local

Note: The caBundle should contain the PEM-encoded root certificate from your step-ca. You can extract it using:

kubectl get configmap step-ca-step-certificates-certs -n step-system -o jsonpath="{.data['root_ca.crt']}"

The StepIssuer is a custom resource provided by step-issuer that integrates with cert-manager. It defines how cert-manager should connect to your step-ca Certificate Authority to request and renew certificates.

2. Request a Certificate using cert-manager

apiVersion: cert-manager.io/v1
kind: CertificateRequest
metadata:
  name: test-cert
  namespace: step-system
spec:
  request: <BASE64_ENCODED_CSR>
  duration: 24h
  issuerRef:
    name: step-issuer
    kind: StepIssuer
    group: cert-manager.step.sm

Note: The request field must be a base64-encoded CSR in DER format. You can generate a CSR using OpenSSL or step CLI, then base64-encode it before pasting.

The above resource will submits the CSR to the step-issuer, which will request a signed certificate from the step-ca. Once approved, the signed certificate will be returned in the status.certificate field of the CertificateRequest resource.

Documentation and Resources

• Step-issuer Github Repository
• Step-issuer Helm Chart

What are Chainguard Containers?

Chainguard Containers are minimal container images that are secure by default.

In many cases, the Chainguard Containers tagged as :latest contain only an open-source application and its runtime dependencies. These minimal container images typically do not contain a shell or package manager. Chainguard Containers are built with Wolfi, our Linux undistro designed to produce container images that meet the requirements of a more secure software supply chain.

The main features of Chainguard Containers include:

• Minimal design, without unnecessary software bloat
• Daily builds to ensure container images are up-to-date with available security patches
• High quality build-time SBOMs attesting to the provenance of all artifacts within the image
• Verifiable signatures provided by Sigstore
• Reproducible builds with Cosign and apko (read more about reproducibility)

For cases where you need container images with shells and package managers to build or debug, most Chainguard Containers come paired with a -dev variant.

Although the -dev container image variants have similar security features as their more minimal versions, they feature additional software that is typically not necessary in production environments. We recommend using multi-stage builds to leverage the -dev variants, copying application artifacts into a final minimal container that offers a reduced attack surface that won’t allow package installations or logins.

Learn More

To better understand how to work with Chainguard Containers, please visit Chainguard Academy and Chainguard Courses.

In addition to Containers, Chainguard offers VMs and Libraries. Contact Chainguard to access additional products.

Trademarks

This software listing is packaged by Chainguard. The trademarks set forth in this offering are owned by their respective companies, and use of them does not imply any affiliation, sponsorship, or endorsement by such companies.