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$ watch -x kubectl get pod,node -o wide -A # NAMESPACE The following screen will appear, which updatesNAME periodically Every 2.0s: kubectl get pod,node -o wide -A READY STATUS node1: TueRESTARTS Mar 9 17:18:01 2021 NAMESPACE AGE NAME IP NODE NOMINATED NODE READINESS GATES ingress-nginx pod/ingress-nginx-controller-d6vp7 READY STATUS RESTARTS 1/1 AGE IP Running 0 NODE default 12d pod/netchecker-agent-hostnet-l6s5x 10.233.97.26 master1 <none> 1/1 Running 0 <none> kube-system pod/calico-kube-controllers-744ccf69c7-rjwk2 25h 192.168.100.181/1 node1 default Running 0 pod/netchecker-agent-hostnet-rf5jl 1/1 5d21h Running10.233.110.40 0 worker1 <none> 25h 192.168.100.23 node2 default <none> kube-system pod/netcheckercalico-agentnode-hostnet-sc5h74f8n7 1/1 Running 0 25h 12d 192.168.100.25206 worker1 node3 default <none> pod/netchecker-agent-kqsz7 <none> kube-system pod/calico-node-6wkqb 1/1 Running 0 25h 1/1 10.233.90.3 Running 0 node1 default pod/netchecker-agent-lp5pf 12d 192.168.100.94 worker3 <none> 1/1 Running 0<none> kube-system pod/calico-node-9ptsg 25h 10.233.92.2 node3 default pod/netchecker-agent-z7vb5 1/1 Running 0 1/1 Running 12d 0 192.168.100.102 master2 25h<none> 10.233.96.2 node2 default <none> kube-system pod/netcheckercalico-servernode-f98789d55-xr6n9b64qh 1/1 Running 2 24h 10.233.96.81/1 Running 0 node2 kube-system pod/calico-kube-controllers-596bd759d5-x2zqc 1/1 12d Running 192.168.100.190 0 worker2 <none> 24h 192.168.100.23 node2<none> kube-system pod/calico-node-772q2lh7p2 1/1 Running 0 12d 25h 192.168.100.2324 master1 <none> node2<none> kube-system pod/calicocoredns-node-lnh5z 645b46f4b6-w4v57 1/1 Running 0 25h 192.168.100.25 node3 kube-system5d21h pod/calico-node-zcqjh10.233.98.24 master2 <none> <none> kube-system 1/1pod/coredns-645b46f4b6-zmqwk Running 0 25h 192.168.100.18 node1 kube-system1/1 pod/coredns-657959df74-7289c Running 0 1/1 5d21h 10.233.97.30 Running 0 master1 <none> 24h 10.233.96.7 node2<none> kube-system pod/corednsdns-autoscaler-657959df74-rtl2d 7f7b458498-kv2k9 1/1 Running 0 24h5d21h 10.233.90.497.28 master1 node1 kube-system<none> pod/dns-autoscaler-b5c786945-brq6n <none> kube-system 1/1pod/kube-apiserver-master1 Running 0 24h 10.233.90.5 1/1 node1 kube-system Running pod/kube-apiserver-node1 15 12d 1/1192.168.100.24 master1 Running <none> 0 25h 192.168.100.18 node1<none> kube-system pod/kube-controller-manager-node1apiserver-master2 1/1 Running 011 (36h ago) 12d 25h 192.168.100.18102 node1 kube-systemmaster2 pod/kube-proxy-67lvh<none> <none> kube-system pod/kube-controller-manager-master1 1/1 Running 17 0 12d 24h 192.168.100.1824 master1 <none> node1<none> kube-system pod/kube-controller-proxymanager-whqwbmaster2 1/1 Running 14 (36h ago) 1/1 12d Running 0192.168.100.102 master2 <none> 24h 192.168.100.25 node3<none> kube-system pod/kube-proxy-zs6kfdtsjz 1/1 Running 0 24h5d21h 192.168.100.2394 node2 kube-system worker3 pod/kube-scheduler-node1 <none> <none> kube-system pod/kube-proxy-ft984 1/1 Running 0 25h 192.168.100.18 node1 kube-system1/1 pod/metrics-server-5cd75b7749-d2594 Running 0 2/2 Running 05d21h 192.168.100.206 worker1 <none> 24h 10.233.90.6 node1<none> kube-system pod/nginxkube-proxy-node2hht9g 1/1 Running 0 25h 5d21h 192.168.100.2324 master1 <none> node2<none> kube-system pod/nginxkube-proxy-node3nqbw5 1/1 Running 0 25h 192 5d21h 192.168.100.25102 master2 <none> node3<none> kube-system pod/nodelocaldns-hj5t8kube-proxy-z6mzs 1/1 Running 0 25h5d21h 192.168.100.18190 node1 kube-systemworker2 pod/nodelocaldns-j7zvh<none> <none> kube-system pod/kube-scheduler-master1 1/1 Running 0 1/1 25h Running 192.168.100.23 node2 kube-system pod/nodelocaldns-jqbx7 12 (4d12h ago) 12d 192.168.100.24 master1 <none> 1/1<none> kube-system Runningpod/kube-scheduler-master2 0 25h 192.168.100.25 node3 NAMESPACE 1/1 NAME Running 14 (36h STATUSago) ROLES 12d 192.168.100.102 master2 <none> AGE VERSION INTERNAL<none> kube-IPsystem EXTERNAL-IP OS-IMAGEpod/kubernetes-dashboard-5c5f5d4547-mxgmp 1/1 Running 0 5d21h 10.233.103.30 worker2 <none> <none> kube-system pod/kubernetes-metrics-scraper-756f68fffd-dqcmk 1/1 Running 0 5d21h 10.233.110.39 worker1 <none> <none> kube-system pod/metrics-server-69d9447b96-td7z7 1/1 Running 0 5d21h 10.233.103.31 worker2 <none> <none> kube-system pod/nginx-proxy-worker1 1/1 Running 0 12d 192.168.100.206 worker1 <none> <none> kube-system pod/nginx-proxy-worker2 1/1 Running 0 12d 192.168.100.190 worker2 <none> <none> kube-system pod/nginx-proxy-worker3 1/1 Running 0 12d 192.168.100.94 worker3 <none> <none> kube-system pod/nodelocaldns-64678 1/1 Running 6 (9d ago) 12d 192.168.100.190 worker2 <none> <none> kube-system pod/nodelocaldns-d6c5r 1/1 Running 0 12d 192.168.100.94 worker3 <none> <none> kube-system pod/nodelocaldns-l6ms9 1/1 Running 2 (9d ago) 12d 192.168.100.102 master2 <none> <none> kube-system pod/nodelocaldns-q2dm9 1/1 Running 1 (12d ago) 12d 192.168.100.206 worker1 <none> <none> kube-system pod/nodelocaldns-r9m9q 1/1 Running 0 12d 192.168.100.24 master1 <none> <none> NAMESPACE NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME node/master1 Ready control-plane,master 252d v1.26.5 192.168.100.24 <none> Rocky Linux 8.8 (Green Obsidian) 4.18.0-477.27.1.el8_8.x86_64 containerd://1.7.1 node/master2 Ready control-plane,master 252d v1.26.5 192.168.100.102 <none> Rocky Linux 8.8 (Green Obsidian) 4.18.0-477.27.1.el8_8.x86_64 containerd://1.7.1 node/node1worker1 Ready worker Ready control-plane,master 25h252d v1.2026.45 192.168.100.18206 <none> CentOSRocky Linux 8.8 (Green Obsidian) 4.18.0-477.27.1.el8_8.x86_64 containerd://1.7.1 node/node2worker2 Ready <none>worker 25h252d v1.2026.45 192.168.100.23190 <none> CentOSRocky Linux 8.8 (Green Obsidian) 4.18.0-477.27.1.el8_8.x86_64 containerd://1.7.1 node/node3worker3 Ready <none>worker 25h252d v1.2026.45 192.168.100.2594 <none> CentOSRocky Linux 8.8 (Green Obsidian) 4.18.0-477.27.1.el8_8.x86_64 containerd://1.7.1 |
The nodes are not updated at the same time, but in turn. The node being updated changes its STATUS to Ready, SchedulingDisabled. As long as it remains in this state, you will notice that all the Pods implemented on it are eliminated and moved to the other available nodes (i.e. the node is in Drain state). Once the update is finished, it will return to to Ready and move on to the next node.
Ansible tags
There is a quick way to update only a single aspect of our cluster. Thanks to the tags, we can launch the playbook cluster.yml, which will only update a specific part of the configuration. Let's suppose we want to change the configuration of the ingress, present in the addons.yml file. We make our modification and then, instead of running the playbook upgrade-cluster.yml, we use the command
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