Delete Work Node¶

If the node is simply removed from Kubernetes, the ovn-controller process running in ovs-ovn on the node will periodically connect to ovn-central to register relevant network information. This leads to additional resource waste and potential rule conflict risk。 Therefore, when removing nodes from within Kubernetes, follow the steps below to ensure that related resources are cleaned up properly.

This document describes the steps to delete a worker node, if you want to change the node where ovn-central is located, please refer to Replace ovn-central Node.

Evict Pods on the Node¶

 # kubectl drain kube-ovn-worker --ignore-daemonsets --force
 node/kube-ovn-worker cordoned
 WARNING: ignoring DaemonSet-managed Pods: kube-system/kube-ovn-cni-zt74b, kube-system/kube-ovn-pinger-5rxfs, kube-system/kube-proxy-jpmnm, kube-system/ovs-ovn-v2kll
 evicting pod kube-system/coredns-64897985d-qsgpt
 evicting pod local-path-storage/local-path-provisioner-5ddd94ff66-llss6
 evicting pod kube-system/kube-ovn-controller-8459db5ff4-94lxb
 pod/kube-ovn-controller-8459db5ff4-94lxb evicted
 pod/coredns-64897985d-qsgpt evicted
 pod/local-path-provisioner-5ddd94ff66-llss6 evicted
 node/kube-ovn-worker drained

Stop kubelet and docker¶

This step stops the ovs-ovn container to avoid registering information to ovn-central. Log into to the corresponding node and ruu the following commands:

systemctl stop kubelet
systemctl stop docker

Cleanup Files on Node¶

rm -rf /var/run/openvswitch
rm -rf /var/run/ovn
rm -rf /etc/origin/openvswitch/
rm -rf /etc/origin/ovn/
rm -rf /etc/cni/net.d/00-kube-ovn.conflist
rm -rf /etc/cni/net.d/01-kube-ovn.conflist
rm -rf /var/log/openvswitch
rm -rf /var/log/ovn

Delete the Node¶

kubectl delete no kube-ovn-01

Check If Node Removed from OVN-SB¶

In the example below, the node kube-ovn-worker is not removed:

# kubectl ko sbctl show
Chassis "b0564934-5a0d-4804-a4c0-476c93596a17"
  hostname: kube-ovn-worker
  Encap geneve
      ip: "172.18.0.2"
      options: {csum="true"}
  Port_Binding kube-ovn-pinger-5rxfs.kube-system
Chassis "6a29de7e-d731-4eaf-bacd-2f239ee52b28"
  hostname: kube-ovn-control-plane
  Encap geneve
      ip: "172.18.0.3"
      options: {csum="true"}
  Port_Binding coredns-64897985d-nbfln.kube-system
  Port_Binding node-kube-ovn-control-plane
  Port_Binding local-path-provisioner-5ddd94ff66-h4tn9.local-path-storage
  Port_Binding kube-ovn-pinger-hf2p6.kube-system
  Port_Binding coredns-64897985d-fhwlw.kube-system

Delete the Chassis Manually¶

Use the uuid find above to delete the chassis:

# kubectl ko sbctl chassis-del b0564934-5a0d-4804-a4c0-476c93596a17
# kubectl ko sbctl show
Chassis "6a29de7e-d731-4eaf-bacd-2f239ee52b28"
  hostname: kube-ovn-control-plane
  Encap geneve
      ip: "172.18.0.3"
      options: {csum="true"}
  Port_Binding coredns-64897985d-nbfln.kube-system
  Port_Binding node-kube-ovn-control-plane
  Port_Binding local-path-provisioner-5ddd94ff66-h4tn9.local-path-storage
  Port_Binding kube-ovn-pinger-hf2p6.kube-system
  Port_Binding coredns-64897985d-fhwlw.kube-system

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Last update: July 5, 2022
Created: June 30, 2022