Catalogue all images of a Kubernetes cluster to multiple targets with Syft.
This operator maintains a central place to track all packages and software used in all those images in a Kubernetes cluster. For this a Software Bill of Materials (SBOM) is generated from each image with Syft. They are all stored in one or more targets. Currently Git, Dependency Track, OCI-Registry and ConfigMaps are supported. With this it is possible to do further analysis, vulnerability scans and much more in a single place. To prevent scans of images that have already been analyzed pods are annotated with the imageID of the already processed image.
The image contains versions of k8s.io/client-go. Kubernetes aims to provide forwards & backwards compatibility of one minor version between client and server:
| sbom-operator | k8s.io/{api,apimachinery,client-go} | expected kubernetes compatibility |
|---|---|---|
| main | v0.26.2 | 1.25.x, 1.26.x, 1.27.x |
| 0.25.0 | v0.26.2 | 1.25.x, 1.26.x, 1.27.x |
| 0.24.0 | v0.26.0 | 1.25.x, 1.26.x, 1.27.x |
| 0.23.0 | v0.26.0 | 1.25.x, 1.26.x, 1.27.x |
| 0.22.0 | v0.25.4 | 1.24.x, 1.25.x, 1.26.x |
| 0.21.0 | v0.25.3 | 1.24.x, 1.25.x, 1.26.x |
| 0.20.0 | v0.25.2 | 1.24.x, 1.25.x, 1.26.x |
| 0.19.0 | v0.25.2 | 1.24.x, 1.25.x, 1.26.x |
| 0.18.0 | v0.25.2 | 1.24.x, 1.25.x, 1.26.x |
| 0.17.0 | v0.25.1 | 1.24.x, 1.25.x, 1.26.x |
| 0.16.0 | v0.25.0 | 1.24.x, 1.25.x, 1.26.x |
| 0.15.0 | v0.24.4 | 1.23.x, 1.24.x, 1.25.x |
| 0.14.0 | v0.24.3 | 1.23.x, 1.24.x, 1.25.x |
| 0.13.0 | v0.24.2 | 1.23.x, 1.24.x, 1.25.x |
| 0.12.0 | v0.24.1 | 1.23.x, 1.24.x, 1.25.x |
| 0.11.0 | v0.24.0 | 1.23.x, 1.24.x, 1.25.x |
| 0.10.0 | v0.23.6 | 1.22.x, 1.23.x, 1.24.x |
| 0.9.0 | v0.23.5 | 1.22.x, 1.23.x, 1.24.x |
| 0.8.0 | v0.23.5 | 1.22.x, 1.23.x, 1.24.x |
| 0.7.0 | v0.23.4 | 1.22.x, 1.23.x, 1.24.x |
| 0.6.0 | v0.23.4 | 1.22.x, 1.23.x, 1.24.x |
| 0.5.0 | v0.23.4 | 1.22.x, 1.23.x, 1.24.x |
| 0.4.1 | v0.23.3 | 1.22.x, 1.23.x, 1.24.x |
| 0.3.1 | v0.23.3 | 1.22.x, 1.23.x, 1.24.x |
| 0.2.0 | v0.23.2 | 1.22.x, 1.23.x, 1.24.x |
| 0.1.0 | v0.23.2 | 1.22.x, 1.23.x, 1.24.x |
However, the operator will work with more versions of Kubernetes in general.
The operator relies on the syft-internal mechanism to download images from OCI-compliant registries.
kubectl apply -f deploy/standard/
Create a YAML file first with the required configurations or use helm-flags instead.
helm repo add ckotzbauer https://ckotzbauer.github.io/helm-charts
helm install ckotzbauer/sbom-operator -f your-values.yaml
All parameters are cli-flags. The flags can be configured as args or as environment-variables prefixed with SBOM_ to inject sensitive configs as secret values.
| Parameter | Required | Default | Description |
|---|---|---|---|
verbosity |
false |
info |
Log-level (debug, info, warn, error, fatal, panic) |
cron |
false |
"" |
Backround-Service interval (CRON). See Trigger for details. |
ignore-annotations |
false |
false |
Force analyzing of all images, including those from annotated pods. |
format |
false |
json |
SBOM-Format. (One of json, syftjson, cyclonedxjson, spdxjson, github, githubjson, cyclonedx, cyclone, cyclonedxxml, spdx, spdxtv, spdxtagvalue, text, table) |
targets |
false |
git |
Comma-delimited list of targets to sent the generated SBOMs to. Possible targets git, dtrack, oci, configmap. Ignored with a job-image |
pod-label-selector |
false |
"" |
Kubernetes Label-Selector for pods. |
namespace-label-selector |
false |
"" |
Kubernetes Label-Selector for namespaces. |
fallback-image-pull-secret |
false |
"" |
Kubernetes Pull-Secret Name to load as a fallback when all others fail (must be in the same namespace as the sbom-operator) |
registry-proxy |
false |
[] |
Proxy-Registry-Hosts to use. Flag can be used multiple times. Value-Mapping e.g. docker.io=ghcr.io |
args:
targets: git
git-author-email: XXX
git-author-name: XXX
git-repository: https://github.com/XXX/XXX
git-path: dev-cluster/sboms
verbosity: debug
cron: "0 30 * * * *"
envVars:
- name: SBOM_GIT_ACCESS_TOKEN
valueFrom:
secretKeyRef:
name: "sbom-operator"
key: "accessToken"With the cron flag set, the operator runs with a specified interval and checks for changed images in your cluster.
All options from github.com/robfig/cron are allowed as cron-syntax.
When you omit the cron flag, the operator uses a Cache-Informer to process changed pods immediately. In this mode there's also
a one-time analysis at startup to sync the targets with the actual cluster-state. If you configured a job-image there's no initial
startup sync.
It is possible to store the generated SBOMs to different targets (even multple at once). All targets are using Syft as analyzer. If you want to use another tool to analyze your images, then have a look at the Job image section. Images which are not present in the cluster anymore are removed from the configured targets (except for the OCI-Target).
| Parameter | Required | Default | Description |
|---|---|---|---|
dtrack-base-url |
true when dtrack target is used |
"" |
Dependency-Track base URL, e.g. 'https://dtrack.example.com' |
dtrack-api-key |
true when dtrack target is used |
"" |
Dependency-Track API key |
dtrack-label-tag-matcher |
false |
"" |
Dependency-Track Pod-Label-Tag matcher regex |
kubernetes-cluster-id |
false |
"default" |
Kubernetes Cluster ID (to be used in Dependency-Track or Job-Images) |
Each image in the cluster is created as project with the full-image name (registry and image-path without tag) and the image-tag as project-version.
When there's no image-tag, but a digest, the digest is used as project-version.
The autoCreate option of DT is used. You have to set the --format flag to cyclonedx with this target.
| Parameter | Required | Default | Description |
|---|---|---|---|
git-workingtree |
false |
/work |
Directory to place the git-repo. |
git-repository |
true when git target is used. |
"" |
Git-Repository-URL (HTTPS). |
git-branch |
false |
main |
Git-Branch to checkout. |
git-path |
false |
"" |
Folder-Path inside the Git-Repository. |
git-author-name |
true when git target is used. |
"" |
Author name to use for Git-Commits. |
git-author-email |
true when git target is used. |
"" |
Author email to use for Git-Commits. |
git-access-token |
false |
"" |
Git-Personal-Access-Token with write-permissions. |
git-username |
false |
"" |
Git-Username |
git-password |
false |
"" |
Git-Password |
github-app-id |
false |
"" |
GitHub App-ID. |
github-app-installation-id |
false |
"" |
GitHub App-Installation-ID. |
The operator will save all files with a specific folder structure as described below. When a git-path is configured, all folders above this path are not touched
from the application. Assuming that git-path is set to dev-cluster/sboms. When no git-path is given, the structure below is directly in the repository-root.
The structure is basically <git-path>/<registry-server>/<image-path>/<image-digest>/sbom.json (see example below).
The file-extension may differ when another output-format is configured.
You can use a token-based authentication (e.g. a PAT for GitHub) with --git-access-token, BasicAuth with username and password (--git-username, --git-password) or
Github App Authentication (--github-app-id, --github-app-installation-id, env: SBOM_GITHUB_APP_PRIVATE_KEY) The private-key has to be Base64 encoded.
Note: It is required, that the specified branch of the repo is fully initialized. There's no logic which creates a non-existent branch. Just commit a README.md
or something similar, to make things work.
dev-cluster
│
└───sboms
│
└───docker.io
| │
| └───library
| │
| └───busybox
| │
| └───sha256_ae39a6f5...
| │ sbom.json
|
└───ghcr.io
│
└───kyverno
│
└───kyverno
| │
| └───sha256_9e3f14e5...
| │ sbom.json
|
└───kyvernopre
│
└───sha256_e48f87fd...
│ sbom.json
|
└───policy-reporter
│
└───sha256_b70caa7a...
│ sbom.json
| Parameter | Required | Default | Description |
|---|---|---|---|
oci-registry |
true when oci target is used |
"" |
OCI-Registry |
oci-user |
true when oci target is used |
"" |
OCI-User |
oci-token |
true when oci target is used |
"" |
OCI-Token |
In this mode the operator will generate a SBOM and store it into an OCI-Registry. The SBOM then can be processed by cosign, Kyverno or any other tool. E.g.:
COSIGN_REPOSITORY=<yourregistry> cosign download sbom <your full image digest>The operator needs the Registry-URL, a user and a token as password to authenticate to the registry. Write-permissions are needed.
This target stores the SBOM as Kubernetes-ConfigMap. They are placed in the same namespace as the corresponding pod and the name
consists of the pod- and container-name. The configmap is labeled with ckotzbauer.sbom-operator.io=true and
annotated with ckotzbauer.sbom-operator.io/image-id=<full-image-repo-with-digest>.
The content is stored as broli-compressed binary-data with the configmap-key sbom.
| Parameter | Required | Default | Description |
|---|---|---|---|
job-image |
false |
"" |
Job-Image to process images with instead of Syft |
job-image-pull-secret |
false |
"" |
Pre-existing pull-secret-name for private job-images |
job-timeout |
false |
3600 |
Job-Timeout in seconds (activeDeadlineSeconds) |
kubernetes-cluster-id |
false |
"default" |
Kubernetes Cluster ID (to be used in Dependency-Track or Job-Images) |
If you don't want to use Syft to analyze your images, you can give the Job-Image feature a try. The operator creates a Kubernetes-Job which does the analysis with any possible tool inside. There's no target-handling done by the operator, the tool from the job has to process the SBOMs on its own. Currently there are two possible integrations:
| Tool | Description |
|---|---|
| Codenotary CAS | The Community Attestation Service from Codenotary can notarize your images in the Codenotary Cloud. (free) |
| Codenotary VCN | The VCN-Tool from Codenotary can notarize your images in the Codenotary Cloud. (chargeable) |
This feature is built as generic approach. Any image which follows these specs can be used as job-image.
e.g. Manifest (deploy/job-image):
--job-image=ghcr.io/ckotzbauer/sbom-operator/cas:<TAG>e.g. Helm:
jobImageMode: true
envVars:
- name: SBOM_JOB_CAS_API_KEY
value: "<KEY>"All operator-environment variables prefixed with SBOM_JOB_ are passed to the Kubernetes job.
The docker-image is based on a distroless git-image to reduce the attack-surface and keep the image small.
Furthermore the image and release-artifacts are signed with cosign and attested with provenance-files.
The release-process satisfies SLSA Level 2. All of those "metadata files" are also stored in a dedicated repository ghcr.io/ckotzbauer/sbom-operator-metadata.
When discovering security issues please refer to the Security process.
COSIGN_EXPERIMENTAL=1 COSIGN_REPOSITORY=ghcr.io/ckotzbauer/sbom-operator-metadata cosign verify ghcr.io/ckotzbauer/sbom-operator:<tag-to-verify> --certificate-github-workflow-name create-release --certificate-github-workflow-repository ckotzbauer/sbom-operatorCOSIGN_EXPERIMENTAL=1 COSIGN_REPOSITORY=ghcr.io/ckotzbauer/sbom-operator-metadata cosign verify-attestation ghcr.io/ckotzbauer/sbom-operator:<tag-to-verify> --certificate-github-workflow-name create-release --certificate-github-workflow-repository ckotzbauer/sbom-operatorCOSIGN_REPOSITORY=ghcr.io/ckotzbauer/sbom-operator-metadata cosign download attestation ghcr.io/ckotzbauer/sbom-operator:<tag-to-verify> | jq -r '.payload' | base64 -dCOSIGN_REPOSITORY=ghcr.io/ckotzbauer/sbom-operator-metadata cosign download sbom ghcr.io/ckotzbauer/sbom-operator:<tag-to-verify> | jq -r '.payload' | base64 -dPlease refer to the Contribution guildelines.
Please refer to the Conduct guildelines.