Chainguard Container for ksops

KSOPS, or kustomize-SOPS, is a kustomize KRM exec plugin for SOPS encrypted resources. KSOPS can be used to decrypt any Kubernetes resource, but is most commonly used to decrypt encryptedKubernetes Secrets and ConfigMaps. As a kustomize plugin, KSOPS allows you to manage, build, and apply encrypted manifests the same way you manage the rest of your Kubernetes manifests.

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/ksops:latest

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

Compatibility Notes

Chainguard's ksops image contains only the minimum set of tools and dependencies needed to function. It is comparable to the official ksops image..

Getting started

Below is a short guide demonstrating how to:

• Create and encrypt a sample Kubernetes Secret using sops.
• Decrypt it using the ksops image in a Docker container

1. Create a sample Kubernetes Secret

cat <<EOF > secret.yaml
apiVersion: v1
kind: Secret
metadata:
  name: test-secret
type: Opaque
data:
  username: YWRtaW4=
  password: MWYyZDFlMmU2N2Rm
EOF

2. Generate an AGE key pair

age-keygen -o age-key.txt

You can also make use of other tools such as gnupg.

3. Create a SOPS configuration

Use an environment variable to capture the public key:

export AGE_PUBLIC_KEY="$(grep -oE 'age1[0-9a-z]+' age-key.txt)"

Then create a .sops.yaml file to instruct SOPS on how to encrypt only data fields:

cat <<EOF > .sops.yaml
creation_rules:
  - unencrypted_regex: "^(apiVersion|metadata|kind|type)$"
    age: "$AGE_PUBLIC_KEY"
EOF

4. Encrypt the Secret

Use SOPS to encrypt the file:

sops -e secret.yaml > secret.enc.yaml

The resulting secret.enc.yaml file will contain encrypted values for username and password.

5. Create a KSOPS manifest

This manifest references the encrypted file so that kustomize-sops (KSOPS) knows how to handle decryption:

cat <<EOF > secret-generator.yaml
apiVersion: viaduct.ai/v1
kind: ksops
metadata:
  name: test-secret-generator
files:
  - ./secret.enc.yaml
EOF

6. Decrypt with ksops Inside a Docker Container

Replace ORGANIZATION with the appropriate namespace for your image:

docker run --rm \
  -v "$(pwd):/test" \
  -e SOPS_AGE_KEY_FILE=/test/age-key.txt \
  cgr.dev/ORGANIZATION/ksops:latest \
  /test/secret-generator.yaml > decrypted-secret.yaml

7. Verify the Decrypted File

Compare the newly decrypted file against your original secret.yaml (minus metadata fields):

diff <(yq eval 'del(.metadata)' secret.yaml) <(yq eval 'del(.metadata)' decrypted-secret.yaml)

The decrypted-secret.yaml file will look like the original Secret:

apiVersion: v1
kind: Secret
metadata:
  name: test-secret
type: Opaque
data:
  username: YWRtaW4=
  password: MWYyZDFlMmU2N2Rm

Documentation and Resources

For more information, you can refer to the official kustomize-sops documentation.

What are Chainguard Containers?

Chainguard's free tier of Starter container images are built with Wolfi, our minimal Linux undistro.

All other Chainguard Containers are built with Chainguard OS, Chainguard's minimal Linux operating system 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 development, or -dev, variant.

In all other cases, including Chainguard Containers tagged as :latest or with a specific version number, the container images include only an open-source application and its runtime dependencies. These minimal container images typically do not contain a shell or package manager.

Although the -dev container image variants have similar security features as their more minimal versions, they include additional software that is typically not necessary in production environments. We recommend using multi-stage builds to copy artifacts from the -dev variant into a more minimal production image.

Need additional packages?

To improve security, Chainguard Containers include only essential dependencies. Need more packages? Chainguard customers can use Custom Assembly to add packages, either through the Console, chainctl, or API.

To use Custom Assembly in the Chainguard Console: navigate to the image you'd like to customize in your Organization's list of images, and click on the Customize image button at the top of the page.

Learn More

Refer to our Chainguard Containers documentation on Chainguard Academy. Chainguard also offers VMs and Libraries — contact us for access.

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.