From f3b9d0402b99e5c8360fb9cde6f526d3f0d288dd Mon Sep 17 00:00:00 2001 From: Malte Poll Date: Fri, 2 Sep 2022 14:21:19 +0200 Subject: [PATCH] Update Kubernetes version support docs Signed-off-by: Malte Poll --- .github/docs/upgrade-kubernetes.md | 51 +++--------------------------- 1 file changed, 5 insertions(+), 46 deletions(-) diff --git a/.github/docs/upgrade-kubernetes.md b/.github/docs/upgrade-kubernetes.md index da2821bbc..8dbc96127 100644 --- a/.github/docs/upgrade-kubernetes.md +++ b/.github/docs/upgrade-kubernetes.md @@ -1,8 +1,7 @@ # Upgrading Kubernetes -Constellation is a Kubernetes distribution and a sidecar. This means that the Kubernetes version is tracked in multiple places: +Constellation is a Kubernetes distribution. As such, dependencies on Kubernetes versions exist in multiple places: -- Kubernetes linux binaries installed in the CoreOS image (`kubelet`, `kubectl`, `kubeadm`) - The desired Kubernetes version deployed by `kubeadm init` - Kubernetes resources (deployments made while initializing Kubernetes, including the `cloud-controller-manager`, `cluster-autoscaler` and more) - Kubernetes go dependencies for the bootstrapper code @@ -10,53 +9,13 @@ Constellation is a Kubernetes distribution and a sidecar. This means that the Ku ## Understand what has changed -Before changing the Kubernetes version, it is a very good idea to [read the release notes](https://kubernetes.io/releases/notes/) and to identify breaking changes. - - -## Prepare CoreOS images - -CoreOS is the linux distribution that constellation is built on. The Kubernetes components are installed on CoreOS from [the official Kubernetes RPM sources](https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64). -The installed versions of `kubelet`, `kubeadm` and `kubectl` are pinned to a specific version by the [`manifest-lock.x86_64.json`](https://github.com/edgelesssys/constellation-fedora-coreos-config/blob/constellation/manifest-lock.x86_64.json) in the [`constellation-fedora-coreos-config` repository](https://github.com/edgelesssys/constellation-fedora-coreos-config): - -```javascript -{ - "packages": { - // [...] - "kubeadm": { - "evra": "1.23.1-0.x86_64" - }, - "kubectl": { - "evra": "1.23.1-0.x86_64" - }, - "kubelet": { - "evra": "1.23.1-0.x86_64" - }, - // [...] - } - // [...] -} -``` - -New CoreOS images with the desired Kubernetes version should be prepared for testing/debugging and a PR should be opened. - -## Upgrade the pinned Kubernetes version deployed by kubeadm - -Kubeadm is the Kubernetes deployment tool used by constellation. During `kubeadm init`, a Kubernetes version is selected and installed. Using the flag `--kubernetes-version` or the `ClusterConfiguration` field `kubernetesVersion`, this version can be pinned. -To change this version, set the go constant in [`github.com/edgelesssys/constellation/internal/constants.KubernetesVersion`](/internal/constants/constants.go): - -```go -const ( - // [...] - - // KubernetesVersion installed by kubeadm. - KubernetesVersion = "stable-1.23" -) -``` +Before adding support for a new Kubernetes version, it is a very good idea to [read the release notes](https://kubernetes.io/releases/notes/) and to identify breaking changes. ## Upgrading Kubernetes resources -During the cluster initialization, multiple Kubernetes resources are deployed. Some of these should be upgraded with Kubernetes. -Look at [the resources folder](/bootstrapper/internal/kubernetes/k8sapi/resources) and decide what needs to be upgraded. Cloud provider specific images are defined in [`github.com/edgelesssys/internal/versions`](/internal/versions/versions.go). You can check available version tags for container images using [the container registry tags API](https://docs.docker.com/registry/spec/api/#listing-image-tags): +Everything related to Kubernetes versions is tracked in [the versions file](/internal/versions/versions.go). Add a new `ValidK8sVersion` and fill out the `VersionConfigs` entry for that version. +During cluster initialization, multiple Kubernetes resources are deployed. Some of these should be upgraded with Kubernetes. +You can check available version tags for container images using [the container registry tags API](https://docs.docker.com/registry/spec/api/#listing-image-tags): ``` curl -q https://k8s.gcr.io/v2/autoscaling/cluster-autoscaler/tags/list | jq .tags