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 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.