version-checker

version-checker is a Kubernetes utility for observing the current versions of images in use 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.

This tool is currently experimental.

Registries

version-checker currently supports the following registries:

docker (docker hub etc.)
gcr (inc gcr facades such as k8s.gcr.io)
quay

These registries support authentication.

Installation

version-checker can be installed as either static manifests;

$ cd ./deploy/yaml && kubectl apply -f .

Or through helm;

$ cd ./deploy/charts/version-checker && kubectl create namespace verison-checker
$ helm install version-checker . -n version-checker

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

Grafana Dashboard

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

Grafana Dashboard

Options

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 are ignored when this is set.

Metrics

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

Future Development

Support self hosted repositories.
Image URL overwrites (to service registries which are mirroring images).
Support more registry APIs.