use a different volume for the certificates when kubeadm upgrade apply.

"kubeadm upgrade node" may use different dirs

var-lib-kubelet-pki is used by kubeadm upgrade apply to store the certificates

https://github.com/pacoxu/kubeadm-operator/blob/8f3b2f906aadd6f739b7244b9d2f5fc3f8d4a936/controllers/util.go#L172

                                    MountPath: "/etc/kubernetes",
                                },
                                // TODO: use a different volume for the certificates when kubeadm upgrade apply.
                                // "kubeadm upgrade node" may use different dirs
                                // var-lib-kubelet-pki is used by kubeadm upgrade apply to store the certificates
                                {
                                    Name:      "var-lib-kubelet-pki",
                                    MountPath: "/var/lib/kubelet/pki",
                                },
                                // crictl is used by kubeadm upgrade apply to check the binary like `crictl`
                                {
                                    Name:      "crictl",
                                    MountPath: "/usr/local/bin/crictl",
                                },
                                // cp is used by kubeadm upgrade apply to run command like `cp`
                                {
                                    Name:      "cp",
                                    MountPath: "/usr/bin/cp",
                                },
                                // run is used to check container runtime status
                                {
                                    Name:      "run",
                                    MountPath: "/run",
                                },
                                // /var/lib/etcd is for etcd back during kubeadm upgrade apply
                                {
                                    Name:      "etcd-data-dir",
                                    MountPath: "/var/lib/etcd",
                                },
                            },
                        },
                    },

bf96bbd8d75fd4aca3b69afca9a05f44a345b32a

pacoxu / kubeadm-operator

use a different volume for the certificates when kubeadm upgrade apply. #35