version-checker is a Kubernetes utility for observing the current versions of images running in the cluster, as well as the latest available upstream. These checks get exposed as Prometheus metrics to be viewed on a dashboard, or soft alert cluster operators.

version-checker supports the following registries:

• ACR
• Docker Hub
• ECR
• GCR (inc gcr facades such as k8s.gcr.io)
• Quay
• Self Hosted (Docker V2 API compliant registries, e.g. registry, artifactory etc.). Multiple self hosted registries can be configured at once.

These registries support authentication.

version-checker can be installed as either static manifests;

$ kubectl apply -k ./deploy/yaml

Or through helm;

$ helm repo add jetstack https://charts.jetstack.io
"jetstack" has been added to your repositories
$ helm install version-checker jetstack/version-checker
NAME: version-checker
LAST DEPLOYED: Wed Jul 12 17:47:41 2023
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None

The helm chart supports creating a Prometheus/ServiceMonitor to expose the version-checker metrics.

A grafana dashboard is also available to view the image versions as a table.

Grafana Dashboard

By default, without the flag -a, --test-all-containers, version-checker will only test containers where the pod has the annotation enable.version-checker.io/*my-container*, where *my-container* is the name of the container in the pod.

version-checker supports the following annotations present on other pods to enrich version checking on image tags:

• pin-major.version-checker.io/my-container: 4: will pin the major version to check to 4 (v4.0.0).

• pin-minor.version-checker.io/my-container: 3: will pin the minor version to check to 3 (v0.3.0).

• pin-patch.version-checker.io/my-container: 23: will pin the patch version to check to 23 (v0.0.23).

• use-metadata.version-checker.io/my-container: "true": will allow to search for image tags which contain information after the first part of the semver string. For example, this can be pre-releases or build metadata (v1.2.4-alpha.0, v1.2.3-debian-r3).

• use-sha.version-checker.io/my-container: "true": will check against the latest SHA tag available. Essentially, the latest image by date. This is silently set to true if no image tag, or "latest" image tag is set. Cannot be used with any other options.

• match-regex.version-checker.io/my-container: ^v\d+\.\d+\.\d+-debian-: is used for only comparing against image tags which match the regex set. For example, the above annotation will only check against image tags which have the form of something like v1.3.4-debian-r30. use-metadata.version-checker.io is not required when this is set. All other options, apart from URL overrides, are ignored when this is set.

• override-url.version-checker.io/my-container: docker.io/bitnami/etcd: is used to change the URL for where to lookup where the latest image version is. In this example, the current version of my-container will be compared against the image versions in the docker.io/bitnami/etcd registry.

By default, version-checker will expose the version information as Prometheus metrics on 0.0.0.0:8080/metrics.