How to Uninstall the Cluster

If you experience issues specific to Kubernetes running on the cluster, you can directly uninstall the rke2 cluster. To do that, take the following steps:

1. Depending on your installation profile, run one of the following commands:

   1. In an online setup, run the following script with elevated privileges, i.e. sudo, on each node of the cluster. This will uninstall the nodes.

      function remove_rke2_entry_from_exclude() {
        local current_exclude_list new_exclude_list
        YUM_CONF_FILE=$1
        if [[ ! -s "${YUM_CONF_FILE}" ]];
        then
          # File is empty
          return
        fi
        current_exclude_list=$(grep 'exclude=' "${YUM_CONF_FILE}" | tail -1)
        if echo "$current_exclude_list" | grep -q 'rke2-*';
        then
          if [[ -w ${YUM_CONF_FILE} ]];
          then
            new_exclude_list=$(printf '%s\n' "${current_exclude_list//rke2-* /}")
            new_exclude_list=$(printf '%s\n' "${new_exclude_list//rke2-*,/}")
            new_exclude_list=$(printf '%s\n' "${new_exclude_list//rke2-\*/}")
            sed -i "/exclude=.*rke2-\*/d" "${YUM_CONF_FILE}"
            echo "${new_exclude_list}" >> "${YUM_CONF_FILE}"
          else
            error "${YUM_CONF_FILE} file is readonly and contains rke2-* under package exclusion. Please remove the entry for AS to work."
          fi
        fi
      }
      
      function enable_rke2_package_upgrade() {
        remove_rke2_entry_from_exclude /etc/dnf/dnf.conf
        remove_rke2_entry_from_exclude /etc/yum.conf
      }
      
      enable_rke2_package_upgrade
      
      service_exists() {
          local n=$1
          if [[ $(systemctl list-units --all -t service --full --no-legend "$n.service" | cut -f1 -d' ') == $n.service ]]; then
              return 0
          else
              return 1
          fi
      }
      if service_exists rke2-server; then
        systemctl stop rke2-server
        systemctl disable rke2-server
      fi
      if service_exists rke2-agent; then
        systemctl stop rke2-agent
        systemctl disable rke2-agent
      fi
      if [ -e /usr/bin/rke2-killall.sh ]
      then
          echo "Running rke2-killall.sh"
          /usr/bin/rke2-killall.sh > /dev/null
      else
          echo "File not found: rke2-killall.sh"
      fi
      if [ -e /usr/bin/rke2-uninstall.sh ]
      then
          echo "Running rke2-uninstall.sh"
          /usr/bin/rke2-uninstall.sh > /dev/null
      else
          echo "File not found: rke2-uninstall.sh"
      fi
      
      crontab -l > backupcron
      sed -i '/backupjob/d' backupcron > /dev/null
      crontab backupcron > /dev/null
      rm -rf backupcron > /dev/null
      rm -rfv /usr/bin/backupjob > /dev/null
      rm -rfv /etc/rancher/ > /dev/null
      rm -rfv /var/lib/rook/ > /dev/null
      rm -rfv /var/lib/longhorn/ > /dev/null
      rm -rfv /var/lib/rancher/rke2/server/db/* > /dev/null
      umount -l -f /var/lib/rancher/rke2/server/db > /dev/null 2>&1 || true
      rm -rfv /var/lib/rancher/* > /dev/null
      umount -l -f /var/lib/rancher
      rm -rfv /var/lib/rancher/* > /dev/null
      while ! rm -rfv /var/lib/kubelet/* > /dev/null; do
        findmnt --list   --submounts  -n -o TARGET  --target /var/lib/kubelet | grep '/var/lib/kubelet/plugins'  | xargs -r umount -f -l
        sleep 5
      done
      umount -l -f /var/lib/kubelet
      rm -rfv /var/lib/kubelet/* > /dev/null
      rm -rfv /datadisk/* > /dev/null
      umount -l -f /datadisk
      rm -rfv /datadisk/* > /dev/null
      rm -rfv ~/.uipath/* > /dev/null
      mount /var/lib/rancher
      mkdir -p /var/lib/rancher/rke2/server/db/ && mount -a
      rm -rfv /var/lib/rancher/rke2/server/db/* > /dev/null
      echo "Uninstall RKE complete."

   2. In an offline setup, run the following script with elevated privileges, i.e. sudo, on each node of the cluster. This will uninstall the nodes.

      function remove_rke2_entry_from_exclude() {
        local current_exclude_list new_exclude_list
        YUM_CONF_FILE=$1
        if [[ ! -s "${YUM_CONF_FILE}" ]];
        then
          # File is empty
          return
        fi
        current_exclude_list=$(grep 'exclude=' "${YUM_CONF_FILE}" | tail -1)
        if echo "$current_exclude_list" | grep -q 'rke2-*';
        then
          if [[ -w ${YUM_CONF_FILE} ]];
          then
            new_exclude_list=$(printf '%s\n' "${current_exclude_list//rke2-* /}")
            new_exclude_list=$(printf '%s\n' "${new_exclude_list//rke2-*,/}")
            new_exclude_list=$(printf '%s\n' "${new_exclude_list//rke2-\*/}")
            sed -i "/exclude=.*rke2-\*/d" "${YUM_CONF_FILE}"
            echo "${new_exclude_list}" >> "${YUM_CONF_FILE}"
          else
            error "${YUM_CONF_FILE} file is readonly and contains rke2-* under package exclusion. Please remove the entry for AS to work."
          fi
        fi
      }
      
      function enable_rke2_package_upgrade() {
        remove_rke2_entry_from_exclude /etc/dnf/dnf.conf
        remove_rke2_entry_from_exclude /etc/yum.conf
      }
      
      enable_rke2_package_upgrade
      
      service_exists() {
          local n=$1
          if [[ $(systemctl list-units --all -t service --full --no-legend "$n.service" | cut -f1 -d' ') == $n.service ]]; then
              return 0
          else
              return 1
          fi
      }
      if service_exists rke2-server; then
        systemctl stop rke2-server
        systemctl disable rke2-server
      fi
      if service_exists rke2-agent; then
        systemctl stop rke2-agent
        systemctl disable rke2-agent
      fi
      if [ -e /usr/local/bin/rke2-killall.sh ]
      then
        echo "Running rke2-killall.sh"
        /usr/local/bin/rke2-killall.sh > /dev/null
      else
        echo "File not found: rke2-killall.sh"
      fi
      if [ -e /usr/local/bin/rke2-uninstall.sh ]
      then
        echo "Running rke2-uninstall.sh"
        /usr/local/bin/rke2-uninstall.sh > /dev/null
      else
          echo "File not found: rke2-uninstall.sh"
      fi
      
      crontab -l > backupcron
      sed -i '/backupjob/d' backupcron > /dev/null
      crontab backupcron > /dev/null
      rm -rf backupcron > /dev/null
      rm -rfv /usr/bin/backupjob > /dev/null
      rm -rfv /etc/rancher/ > /dev/null
      rm -rfv /var/lib/rook/ > /dev/null
      rm -rfv /var/lib/longhorn/ > /dev/null
      rm -rfv /var/lib/rancher/rke2/server/db/* > /dev/null
      umount -l -f /var/lib/rancher/rke2/server/db > /dev/null 2>&1 || true
      rm -rfv /var/lib/rancher/* > /dev/null
      umount -l -f /var/lib/rancher
      rm -rfv /var/lib/rancher/* > /dev/null
      while ! rm -rfv /var/lib/kubelet/* > /dev/null; do
        findmnt --list   --submounts  -n -o TARGET  --target /var/lib/kubelet | grep '/var/lib/kubelet/plugins'  | xargs -r umount -f -l
        sleep 5
      done
      umount -l -f /var/lib/kubelet
      rm -rfv /var/lib/kubelet/* > /dev/null
      rm -rfv /datadisk/* > /dev/null
      umount -l -f /datadisk
      rm -rfv /datadisk/* > /dev/null
      rm -rfv ~/.uipath/* > /dev/null
      mount /var/lib/rancher
      mkdir -p /var/lib/rancher/rke2/server/db/ && mount -a
      rm -rfv /var/lib/rancher/rke2/server/db/* > /dev/null
      echo "Uninstall RKE complete."

2. Reboot the node after uninstall.

Important: When uninstalling one of the nodes from the cluster, you must run the following command: kubectl delete node <node_name>. This removes the node from the cluster.