Troubleshooting Controlplane Nodes

This section applies to nodes with the controlplane role.

Check if the Controlplane Containers are Running

There are three specific containers launched on nodes with the controlplane role:

  • kube-apiserver
  • kube-controller-manager
  • kube-scheduler

The containers should have status Up. The duration shown after Up is the time the container has been running.

  1. docker ps -a -f=name='kube-apiserver|kube-controller-manager|kube-scheduler'

Example output:

  1. CONTAINER ID        IMAGE                                COMMAND                  CREATED             STATUS              PORTS               NAMES
  2. 26c7159abbcc        rancher/hyperkube:v1.11.5-rancher1   "/opt/rke-tools/en..."   3 hours ago         Up 3 hours                              kube-apiserver
  3. f3d287ca4549        rancher/hyperkube:v1.11.5-rancher1   "/opt/rke-tools/en..."   3 hours ago         Up 3 hours                              kube-scheduler
  4. bdf3898b8063        rancher/hyperkube:v1.11.5-rancher1   "/opt/rke-tools/en..."   3 hours ago         Up 3 hours                              kube-controller-manager

Controlplane Container Logging

Note: If you added multiple nodes with the controlplane role, both kube-controller-manager and kube-scheduler use a leader election process to determine the leader. Only the current leader will log the performed actions. See Kubernetes leader election how to retrieve the current leader.

The logging of the containers can contain information on what the problem could be.

  1. docker logs kube-apiserver
  2. docker logs kube-controller-manager
  3. docker logs kube-scheduler