Why Does Add-on Installation Fail and Prompt "The release name is already exist"?

Symptom

When an add-on fails to be installed, the error message "The release name is already exist" is returned.

Possible Cause

The add-on release record remains in the Kubernetes cluster. Generally, it is because the cluster etcd has backed up and restored the add-on, or the add-on fails to be installed or deleted.

Solution

Use kubectl to connect to the cluster and manually clear the Secret and Configmap corresponding to add-on release. The following uses autoscaler add-on release as an example.

Connect to the cluster using kubectl, and run the following command to view the Secret list of add-on releases:

kubectl get secret -A |grep cceaddon

The Secret name of an add-on release is in the format of sh.helm.release.v1.cceaddon-{add-on name}.v*. If there are multiple release versions, you can delete their Secrets at the same time.
Run the release secret command to delete the Secrets.

Example:

kubectl delete secret sh.helm.release.v1.cceaddon-autoscaler.v1 sh.helm.release.v1.cceaddon-autoscaler.v2 -nkube-system
If the add-on is created when Helm v2 is used, CCE automatically bumps the v2 release in Configmaps to v3 release in Secrets when viewing the add-ons and their details. The v2 release in the original Configmap is not deleted. Run the following command to view the ConfigMap list of add-on releases:

kubectl get configmap -A | grep cceaddon

The ConfigMap name of an add-on release is in the format of cceaddon-{add-on name}.v*. If there are multiple release versions, you can delete their ConfigMaps at the same time.
Run the release configmap command to delete the ConfigMaps.

Example:

kubectl delete configmap cceaddon-autoscaler.v1 cceaddon-autoscaler.v2 -nkube-system

Deleting resources in kube-system is a high-risk operation. Ensure that the command is correct before running it to prevent resources from being deleted by mistake.
On the CCE console, install add-on and then uninstall it. Ensure that the residual add-on resources are cleared. After the uninstall is complete, install the add-on again.

When installing the add-on for the first time, you may find it abnormal after the installation due to the residual resources of the previous add-on release, which is normal. In this case, you can uninstall the add-on on the console to ensure that the residual resources are cleared and the add-on can run properly after being installed again.