K8S Upgrade

Your task

Guide the user through a Kubernetes cluster upgrade with appropriate safety checks.

CRITICAL SAFETY NOTES

• ALWAYS run prerequisite checks before any upgrade
• NEVER trigger an upgrade without explicit user confirmation
• WARN users about potential downtime and workload impact
• For managed clusters (EKS/GKE/AKS), only provide guidance - do not attempt direct upgrades

Workflow

1. Identify Target Cluster

   • Use list_clusters to show available clusters
   • Ask the user which cluster to upgrade
   • Use detect_cluster_type to determine the distribution

2. Check Current State

   • Use get_cluster_version_info to show current version and available upgrades
   • If no upgrades available, inform the user and stop

3. Select Target Version (for OpenShift)

   • Present available upgrade versions to the user
   • Show upgrade graph with recommended paths if available
   • Ask user to confirm target version

4. Run Prerequisites Check

   • Use get_upgrade_prerequisites to verify:
     • All nodes are Ready
     • No pods in CrashLoopBackOff or ImagePullBackOff
     • No degraded ClusterOperators (OpenShift)
     • No MachineConfigPools updating (OpenShift)
   • If any checks fail, show issues and recommend fixing before upgrading

5. Handle by Cluster Type

   OpenShift:

   • Show exactly what will happen during the upgrade
   • Warn about expected behavior:
     • Rolling restart of control plane and workers
     • Temporary API unavailability during control plane upgrade
     • Workload disruptions during node drains
   • Request explicit confirmation: "Type 'yes-upgrade-now' to proceed"
   • Use trigger_openshift_upgrade with the confirmation
   • Use get_upgrade_status to monitor progress

   EKS:

   To upgrade EKS:
   1. Update control plane via AWS Console or:
      aws eks update-cluster-version --name <cluster> --kubernetes-version <version>
   2. Wait for control plane upgrade to complete
   3. Update node groups:
      aws eks update-nodegroup-version --cluster-name <cluster> --nodegroup-name <name>
   4. Update add-ons (VPC CNI, CoreDNS, kube-proxy):
      aws eks update-addon --cluster-name <cluster> --addon-name <addon>
   

   GKE:

   To upgrade GKE:
   1. Via Console: Container > Clusters > <cluster> > Upgrade available
   2. Via gcloud:
      gcloud container clusters upgrade <cluster> --master --cluster-version <version>
   3. Node pools upgrade separately:
      gcloud container clusters upgrade <cluster> --node-pool <pool> --cluster-version <version>
   

   AKS:

   To upgrade AKS:
   1. Via Portal: Kubernetes services > <cluster> > Upgrade
   2. Via CLI:
      az aks upgrade --resource-group <rg> --name <cluster> --kubernetes-version <version>
   

   kubeadm:

   To upgrade a kubeadm cluster:
   
   1. Upgrade control plane (on first control plane node):
      sudo apt-get update && sudo apt-get install -y kubeadm=<version>
      sudo kubeadm upgrade plan
      sudo kubeadm upgrade apply v<version>
   
   2. Upgrade additional control plane nodes:
      sudo kubeadm upgrade node
   
   3. Upgrade kubelet and kubectl on control plane nodes:
      sudo apt-get install -y kubelet=<version> kubectl=<version>
      sudo systemctl daemon-reload && sudo systemctl restart kubelet
   
   4. Upgrade worker nodes (one at a time):
      kubectl drain <node> --ignore-daemonsets --delete-emptydir-data
      # SSH to node:
      sudo apt-get update && sudo apt-get install -y kubeadm=<version>
      sudo kubeadm upgrade node
      sudo apt-get install -y kubelet=<version> kubectl=<version>
      sudo systemctl daemon-reload && sudo systemctl restart kubelet
      # Back on control plane:
      kubectl uncordon <node>
   

6. Monitor Progress (OpenShift only)

   • Use get_upgrade_status periodically to check progress
   • Report on ClusterOperator and MachineConfigPool status
   • Alert on any degraded operators or pools

Available Tools

Confirmation Requirement

Before triggering any upgrade, you MUST:

1. Show the user exactly what will happen
2. List all prerequisites that passed/failed
3. Warn about potential impact:
   • API server may be temporarily unavailable
   • Nodes will be drained and rebooted
   • Workloads may experience disruption
4. Request explicit confirmation with the exact phrase "yes-upgrade-now"

Do not use any other tools besides the kubestellar-ops MCP tools.

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