How to uninstall the cluster

If you experience issues specific to Kubernetes running on the cluster, you can directly uninstall the rke2 cluster.

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

   1.1. 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
   rm -rfv /etc/sysconfig/rke2-server > /dev/null
   rm -rfv /etc/sysconfig/rke2-agent > /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."

   1.2 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
   rm -rfv /etc/sysconfig/rke2-server > /dev/null
   rm -rfv /etc/sysconfig/rke2-agent > /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. Clean up the OSD disk:

   for osddisk in $(find /dev/uipath/ceph -maxdepth 1 -mindepth 1 -type l); do
     devName=$(basename "${osddisk}")
     devPath="/dev/${devName}"
     sgdisk --zap-all "${devPath}"
     dd if=/dev/zero of="${devPath}" bs=1M count=100 oflag=direct,dsync
     blkdiscard "${devPath}"
   done
   ls /dev/mapper/ceph-* | xargs -I% -- dmsetup remove %  
   rm -rf /dev/ceph-*
   rm -rf /etc/udev/rules.d/99-ceph-raw-osd.rules

   3, 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.