Critical DaemonSets Missing Universal Toleration
Issue
When a node is configured with Taints, it prevents several critical cluster daemonsets from being scheduled on that node(s), causing the cluster to become unstable.
The DaemonSets affected are:
- The
machine-config-daemonds, in the openshift-machine-config-operator project - The
node-cads, in the openshift-image-registry project - The
dns-defaultds, in the openshift-dns project*
This issue is currently being tracked in bugzilla.
If OpenShift Container Storage (OCS) is deployed, it includes the following DaemonSets which are also unable to schedule on nodes that are tainted or on master nodes. (with the exception of storage nodes containing the node.ocs.openshift.io/storage=true:NoSchedule taint):
- The
csi-cephfspluginds, in the openshift-storage project - The
csi-rbdpluginds, in the openshift-storage project
* While the dns-default ds is affected by this issue, testing has determined that it does not critically impact cluster functionality and stability.
Environment
- Red Hat OpenShift Container Platform (OCP) 4.1 - 4.5
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