Creating secret Error:
# kubectl create secret generic thanos-objectstorage –from-file=objstore.yaml -n monitoring
Error Messages:

Error from server (InternalError): Internal error occurred: failed calling webhook “rancher.cattle.io”: Post https://rancher-webhook.cattle-system.svc:443/v1/webhook/mutation?timeout=10s: service “rancher-webhook” not found

According to the error report, it may be a problem with rbac, which cannot create

# kubectl get mutatingwebhookconfigurations
NAME                             WEBHOOKS   AGE
mutating-webhook-configuration   7          156d
rancher.cattle.io                2          156d

# kubectl get validatingwebhookconfigurations
NAME                               WEBHOOKS   AGE
rancher.cattle.io                  2          156d
validating-webhook-configuration   7          156d

There are two admission controllers found in the view, both of which are leftover from the previous installation of components

Just Delete it

# kubectl delete mutatingwebhookconfigurations mutating-webhook-configuration
mutatingwebhookconfiguration.admissionregistration.k8s.io "mutating-webhook-configuration" deleted

# kubectl delete mutatingwebhookconfigurations rancher.cattle.io
mutatingwebhookconfiguration.admissionregistration.k8s.io "rancher.cattle.io" deleted

# kubectl delete validatingwebhookconfigurations rancher.cattle.io
validatingwebhookconfiguration.admissionregistration.k8s.io "rancher.cattle.io" deleted

# kubectl delete validatingwebhookconfigurations validating-webhook-configuration
validatingwebhookconfiguration.admissionregistration.k8s.io "validating-webhook-configuration" deleted