Using Helm at Giant Swarm
- All actions in Helm are scoped to a namespace.
- You can check all namespaces with the
helm ls -A.
- But these aliases based on Vaclav’s awesome
kubectlaliases may help.
alias helmg="helm -n giantswarm" alias helmk="helm -n kube-system" alias helmm="helm -n monitoring"
- Our Giant Swarm App Platform is built on Helm chart repositories.
- app-operator gets the repository URL from the catalog CR but you can also use it locally.
$ helm repo add control-plane-catalog https://giantswarm.github.io/control-plane-catalog/
- Example installing app-operator in KIND.
helm install -n giantswarm app-operator control-plane-catalog/app-operator
- :caution: Be careful when installing charts manually in test MCs and remove them after. Don’t do this in prod MCs unless there is no alternative.
Helm 3: Three Way Merge
- This is one of the major changes in Helm 3. Now the current state of the cluster is included when the strategic merge patch is generated.
- For example if a deployment is scaled down the merge will scale it back up.
- This means manual changes are higher risk with Helm 3.
- To prevent app-operator making changes you can cordon the app CR.
- See the Helm docs for more detail on three way merge.
- See fmt.
Tips & Tricks
Help with common templating issues.
Is a chart deployed with Helm 2 or Helm 3?
- You can use the
- On Helm 3 it is always
- On Helm 2 it is always
Tools, tips and tricks for working with Helm values.
This plugin is useful for comparing values changes. It can also do other comparisions. See the docs.
helm plugin install https://github.com/databus23/helm-diff helm -n giantswarm diff revision release-operator-unique 18 19
helm get values –all
helm get values only returns the overrides for the chart. In our case
the config specified in the app CR.
--all flag shows all the computed values including those in values.yaml in the
Removed API versions
If an apiVersion has been removed then chart-operator will fail to update the helm release. e.g.
current release manifest contains removed kubernetes api(s) for this kubernetes version and it is therefore unable to build the kubernetes objects for performing the diff. error from kubernetes: [unable to recognize \"\": no matches for kind \"Role\" in version \"rbac.authorization.k8s.io/v1beta1\", unable to recognize \"\": no matches for kind \"RoleBinding\" in version \"rbac.authorization.k8s.io/v1beta1\
The apiVersion in the helm release secret needs to be updated to a supported value. This can be done with the https://github.com/helm/helm-mapkubeapis plugin.
It can remap both deprecated and removed API versions.
Install the plugin.
helm plugin install https://github.com/helm/helm-mapkubeapis
Scale down chart-operator.
kubectl -n giantswarm scale deploy chart-operator --replicas 0
helm mapkubeapis -n efk-stack-app efk-stack-app 2022/04/12 13:03:39 Release 'efk-stack-app' will be checked for deprecated or removed Kubernetes APIs and will be updated if necessary to supported API versions. 2022/04/12 13:03:39 Get release 'efk-stack-app' latest version. 2022/04/12 13:03:39 Check release 'efk-stack-app' for deprecated or removed APIs... 2022/04/12 13:03:40 Found 3 instances of deprecated or removed Kubernetes API: "apiVersion: rbac.authorization.k8s.io/v1beta1 kind: Role " Supported API equivalent: "apiVersion: rbac.authorization.k8s.io/v1 kind: Role " 2022/04/12 13:03:40 Found 1 instances of deprecated or removed Kubernetes API: "apiVersion: rbac.authorization.k8s.io/v1beta1 kind: RoleBinding " Supported API equivalent: "apiVersion: rbac.authorization.k8s.io/v1 kind: RoleBinding " 2022/04/12 13:03:40 Finished checking release 'efk-stack-app' for deprecated or removed APIs. 2022/04/12 13:03:40 Deprecated or removed APIs exist, updating release: efk-stack-app. 2022/04/12 13:03:40 Set status of release version 'efk-stack-app.v76' to 'superseded'. 2022/04/12 13:03:40 Release version 'efk-stack-app.v76' updated successfully. 2022/04/12 13:03:40 Add release version 'efk-stack-app.v77' with updated supported APIs. 2022/04/12 13:03:40 Release version 'efk-stack-app.v77' added successfully. 2022/04/12 13:03:40 Release 'efk-stack-app' with deprecated or removed APIs updated successfully to new version. 2022/04/12 13:03:40 Map of release 'efk-stack-app' deprecated or removed APIs to supported versions, completed successfully.
Scale up chart-operator.
kubectl -n giantswarm scale deploy chart-operator --replicas 1