kubeadm 部署的 k8s 增加 ip 并重新生成证书

• 原因是客户环境为双网卡环境，对内和对外有两个不同的网段，因为前期的部署 [那肯定不是我部署的，是我部署，我也不一定注意的到]，因为本机路由不对，没有走对外的网卡，而加入控制节点的时候，没有指定 ip，导致走的默认路由，后期发现了问题，现在需要重新生成证书来修复 etcd 和 apiserver 因为修改 ip 而引发的一系列问题

正片开始

证书的修改，必须要 apiserver 服务可用

备份 kubernetes 目录

cp -r /etc/kubernetes{,-bak}

查看证书内的 ip

for i in $(find /etc/kubernetes/pki -type f -name "*.crt");do echo ${i} && openssl x509 -in ${i} -text | grep 'DNS:';done

可以看到，只有 apiserver 和 etcd 的证书里面是包含了 ip 的

/etc/kubernetes/pki/ca.crt
/etc/kubernetes/pki/front-proxy-ca.crt
/etc/kubernetes/pki/etcd/ca.crt
/etc/kubernetes/pki/etcd/server.crt
                DNS:master-03, DNS:localhost, IP Address:192.168.11.135, IP Address:127.0.0.1, IP Address:0:0:0:0:0:0:0:1
/etc/kubernetes/pki/etcd/healthcheck-client.crt
/etc/kubernetes/pki/etcd/peer.crt
                DNS:master-03, DNS:localhost, IP Address:192.168.11.135, IP Address:127.0.0.1, IP Address:0:0:0:0:0:0:0:1
/etc/kubernetes/pki/apiserver.crt
                DNS:master-03, DNS:kubernetes, DNS:kubernetes.default, DNS:kubernetes.default.svc, DNS:kubernetes.default.svc.cluster.local, DNS:lb-vip, IP Address:10.96.0.1, IP Address:192.168.11.135
/etc/kubernetes/pki/apiserver-kubelet-client.crt
/etc/kubernetes/pki/front-proxy-client.crt
/etc/kubernetes/pki/apiserver-etcd-client.crt

生成集群配置

kubeadm config view > /root/kubeadm.yaml

增加 ip

vim kubeadm.yaml

apiServer:
  extraArgs:
    authorization-mode: Node,RBAC
  timeoutForControlPlane: 4m0s
  # 增加下面的配置
  certSANs:
  - 192.168.11.131
  - 192.168.11.134
  - 192.168.11.136
  # 增加上面的配置
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: lb-vip:6443
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
    # 增加下面的配置
    serverCertSANs:
    - 192.168.11.131
    - 192.168.11.135
    - 192.168.11.136
    peerCertSANs:
    - 192.168.11.131
    - 192.168.11.135
    - 192.168.11.136
    # 增加上面的配置
imageRepository: registry.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.17.3
networking:
  dnsDomain: cluster.local
  podSubnet: 172.10.0.0/16
  serviceSubnet: 10.96.0.0/12
scheduler: {}

删除原有的证书

需要保留 ca ，sa，front-proxy 这三个证书

rm -rf /etc/kubernetes/pki/{apiserver*,front-proxy-client*}
rm -rf /etc/kubernetes/pki/etcd/{healthcheck*,peer*,server*}

重新生成证书

kubeadm init phase certs all --config /root/kubeadm.yaml

再次查看证书内的 ip

for i in $(find /etc/kubernetes/pki -type f -name "*.crt");do echo ${i} && openssl x509 -in ${i} -text | grep 'DNS:';done

这里可以得到验证，不会覆盖之前证书内已经有的 ip，会将新的 ip 追加到后面

/etc/kubernetes/pki/etcd/ca.crt
/etc/kubernetes/pki/etcd/server.crt
                DNS:master-02, DNS:localhost, IP Address:192.168.11.134, IP Address:127.0.0.1, IP Address:0:0:0:0:0:0:0:1, IP Address:192.168.11.131, IP Address:192.168.11.134, IP Address:192.168.11.136
/etc/kubernetes/pki/etcd/peer.crt
                DNS:master-02, DNS:localhost, IP Address:192.168.11.134, IP Address:127.0.0.1, IP Address:0:0:0:0:0:0:0:1, IP Address:192.168.11.131, IP Address:192.168.11.134, IP Address:192.168.11.136
/etc/kubernetes/pki/etcd/healthcheck-client.crt
/etc/kubernetes/pki/ca.crt
/etc/kubernetes/pki/front-proxy-ca.crt
/etc/kubernetes/pki/apiserver.crt
                DNS:master-02, DNS:kubernetes, DNS:kubernetes.default, DNS:kubernetes.default.svc, DNS:kubernetes.default.svc.cluster.local, DNS:lb-vip, IP Address:10.96.0.1, IP Address:192.168.11.134, IP Address:192.168.11.131, IP Address:192.168.11.134, IP Address:192.168.11.136
/etc/kubernetes/pki/apiserver-kubelet-client.crt
/etc/kubernetes/pki/front-proxy-client.crt
/etc/kubernetes/pki/apiserver-etcd-client.crt

将配置更新到 configmap 中

这样，以后有升级，或者增加其他 ip 时，也会将配置的 CertSANs 的 ip 保留下来，方便以后删减

kubeadm init phase upload-config kubeadm --config kubeadm.yaml