Kubernetes Agent Tools Base

This repo produces a container image that is used by the Kubernetes Agent to execute Kubernetes scripts. It contains the minimum required tooling to run Kubernetes workloads for Octopus Deploy.

Summary: The image packages kubectl, helm, powershell and curl on the base image mcr.microsoft.com/dotnet/runtime-deps.

Updating versions

In the root of the directory there is a file, versions.json which contains information about what versions of Kubectl (and thus Kubernetes), Helm & Powershell are used to generate the images. Under the tools object, there are 3 fields with versions arrays (kubectl,helm,powershell), which are used in a matrix to generate the images.

There is also a latest field that represents the kubernetes version that will be tagged with the latest tag.

Tags

There are 4 tags being published

• latest - Assigned to the highest version of the Kubernetes supported by the Kubernetes agent.
• {Kubectl Major Version}.{Kubectl Minor Version} - For each kubectl version, there will be an image with the Kubernetes major & minor version. Example: 1.31.
• {Kubectl Major Version}.{Kubectl Minor Version}-{Random6Chars} - For each kubectl version, there will be an image with the Kubernetes major & minor version and random 6 char revision hash. Example: 1.31-X5msD0.
• kube{Kubectl Version}-helm{Helm Version}-pwsh{Powershell Version}-{Random6Chars} - Contains all versions of the tools plus the revision hash. Example kube1.31.1-helm3.16.1-pwsh7.4.5-X5msD0.

What is the revisionHash?

The revision hash is a "cache-busting" mechanism to allow the Kubernetes agent to get an updated version of the tools container image without needing to set the imagePullPolicy to Always. Because Kubernetes will cache the image on the node(s), it's possible that the image does not get re-acquired when there is a tooling update.

Generating a new revisionHash

As the revisionHash is used in the docker tag, which are case-sensitive, the following command generates a unique 6 char hash.

LC_ALL=C tr -dc A-Za-z0-9 </dev/urandom | head -c 6; echo

Branch builds

Branch builds will only be pushed the Octopus' Artifactory instance with a prerelease version {artifactory-hostname}/octopusdeploy/kubernetes-agent-tools-base:{Kubectll Minor Version}.{Kubectl Minor Version}-{Random6Chars}-{Sanitized Branch Name}-{Date} Example: {artifactory-hostname}/octopusdeploy/kubernetes-agent-tools-base:1.29-X5msD0-tl-push-to-dockerhub-20240424041854

The tags can be found from the logs in the Github action workflow under the step "Create Tag Version`