maintenance.md

Maintenance guide

How to change the supported Kubernetes minor versions

pvc-autoresizer depends on some Kubernetes repositories like k8s.io/client-go and should support 3 consecutive Kubernetes versions at a time.

Issues and PRs related to the last upgrade task also help you understand how to upgrade the supported versions, so checking them together(e.g #85) with this guide is recommended when you do this task.

Upgrade procedure

We should write down in the github issue of this task what are the important changes and the required actions to manage incompatibilities if exist. The format is up to you.

Basically, we should pay attention to breaking changes and security fixes first.

TopoLVM

Choose the TopoLVM version that supports target Kubernetes version.

To change the version, edit versions.mk. If TopoLVM which supports the target Kubernetes version has not released yet, you can specify the commit hash instead of the tag.

Kubernetes

Choose the next version and check the release note. e.g. 1.17, 1.18, 1.19 -> 1.18, 1.19, 1.20

To change the version, edit the following files.

• .github/workflows/e2e.yaml
• README.md
• versions.mk

We should also update go.mod by the following commands. Please note that Kubernetes v1 corresponds with v0 for the release tags. For example, v1.17.2 corresponds with the v0.17.2 tag.

$ VERSION=<upgrading Kubernetes release version>
$ go get k8s.io/api@v${VERSION} k8s.io/apimachinery@v${VERSION} k8s.io/client-go@v${VERSION}

Read the controller-runtime's release note, and update to the newest version that is compatible with all supported kubernetes versions. If there are breaking changes, we should decide how to manage these changes.

$ VERSION=<upgrading controller-runtime version>
$ go get sigs.k8s.io/controller-runtime@v${VERSION}

Read the controller-tools's release note, and update to the newest version that is compatible with all supported kubernetes versions. If there are breaking changes, we should decide how to manage these changes. To change the version, edit versions.mk.

Go

Choose the same version of Go used by the latest Kubernetes supported by pvc-autoresizer.

Edit the following files.

• go.mod
• Dockerfile

Depending tools

The following tools do not depend on other software, use latest versions. To change their versions, edit versions.mk.

• chart-testing
• golangci-lint
• helm-docs
• helm
• kube-prometheus

Depending modules

Please tidy up the dependencies.

$ go mod tidy

Regenerate manifests using new controller-tools.

$ make setup
$ make generate

Final check

git grep <the kubernetes version which support will be dropped>, git grep image:, git grep -i VERSION and looking versions.mk might help to avoid overlooking necessary changes.