kubernetes修改節點名稱

 

有時候由於場景須要，咱們須要修改kubernetes節點的主機名，假設有三個節點分別是：

host1,host2,host3，cni組件使用calico，須要將host1改成master。

在修改kubelet節點主機名的時候也須要修改calico服務中的主機名。具體步驟以下：

一.修改系統主機名

[root@host1 ~]# hostname master

二.修改kubelet節點主機名

修改kubelet啓動參數--hostname-override=master

重啓kubelet服務

[root@master ~]# systemctl restart kubelet

這時查看kubelet運行日誌

[root@master ~]# journalctl -xe -u kubelet

會看到以下報錯

Mar 23 13:15:27 master kubelet[13508]: E0323 13:15:27.320556   13508 kubelet_node_status.go:106] Unable to register node "master" with API server: nodes "master" is forbidden: node "host1" cannot modify node "master"

中止kubelet服務並刪除當前節點

[root@master ~]# systemctl stop kubelet
[root@master ~]# kubectl delete node host1

刪除kubelet.kubeconfig,kubelet.key,kubelet.crt,kubelet-client.key和kubelet-client.crt

[root@master ~]# rm -f /etc/kubernetes/kubelet.kubeconfig
[root@master ~]# rm -f /etc/kubernetes/ssl/kubelet*

再重啓kubelet

[root@master ~]# systemctl restart kubelet

 查看證書狀態

[root@master ~]# kubectl get csr
NAME                                                   AGE       REQUESTOR           CONDITION
node-csr-GIAqC5LBI_7c6TlMW8wugv_TlHfs1CShZhnEyLgxvSI   1m        kubelet-bootstrap   Pending

 容許證書

[root@master ~]# kubectl certificate approve node-csr-GIAqC5LBI_7c6TlMW8wugv_TlHfs1CShZhnEyLgxvSI

 再次查看證書狀態

[root@master ~]# kubectl get csr
NAME                                                   AGE       REQUESTOR           CONDITION
node-csr-GIAqC5LBI_7c6TlMW8wugv_TlHfs1CShZhnEyLgxvSI   1m        kubelet-bootstrap   Approved,Issued

 查看節點狀態

[root@master ~]# kubectl get node
NAME           STATUS    ROLES     AGE       VERSION
host2          Ready     <none>    34m       v1.9.5
host3          Ready     <none>    34m       v1.9.5
master         Ready     <none>    18s       v1.9.5

三.修改calico節點主機名

這時候查看calico運行狀態 

[root@master ~]# calicoctl node status
Calico process is not running.

calico服務會輸出以下錯誤日誌

[WARNING][9] startup.go 757: calico node 'host1' is already using the IPv4 address 10.233.119.0

切換到其餘節點上查看，如host2

[root@host2 ~]# calicoctl get node
NAME    
host1   
host2   
host3
[root@host2 ~]# calicoctl node status
Calico process is running.

IPv4 BGP status
+--------------+-------------------+-------+----------+--------------------------------+
| PEER ADDRESS |     PEER TYPE     | STATE |  SINCE   |              INFO              |
+--------------+-------------------+-------+----------+--------------------------------+
| 10.21.21.254 | node-to-node mesh | start | 05:16:47 | Active Socket: Connection      |
|              |                   |       |          | refused                        |
| 10.21.21.245 | node-to-node mesh | up    | 04:44:35 | Established                    |
+--------------+-------------------+-------+----------+--------------------------------+

IPv6 BGP status
No IPv6 peers found.

獲取host1節點配置，保存輸出內容到文件master.yaml中

[root@host2 ~]# calicoctl get node host1 -o yaml
apiVersion: projectcalico.org/v3
kind: Node
metadata:
  creationTimestamp: 2018-03-23T04:44:29Z
  name: host1
  resourceVersion: "485"
  uid: dfb352cf-2e54-11e8-82e7-52540000361b
spec:
  bgp:
    ipv4Address: 10.21.21.254/16
    ipv4IPIPTunnelAddr: 10.233.119.0

刪除host1

[root@host2 ~]# calicoctl delete node host1
Successfully deleted 1 'Node' resource(s)

修改master.yaml

apiVersion: projectcalico.org/v3
kind: Node
metadata:
  name: master
  uid: dfb352cf-2e54-11e8-82e7-52540000361b
spec:
  bgp:
    ipv4Address: 10.21.21.254/16
    ipv4IPIPTunnelAddr: 10.233.119.0

建立calico節點

[root@host2 ~]# calicoctl apply -f master.yaml 
Successfully applied 1 'Node' resource(s)

刪除異常的calico Pod

[root@host2 ~]# kubectl get pod -n kube-system
NAME                                       READY     STATUS             RESTARTS   AGE
calico-kube-controllers-5f47974799-ttz7s   1/1       Running            0          6m
calico-node-274q9                          2/2       Running            0          40m
calico-node-dp8dz                          2/2       Running            0          40m
calico-node-rh2kd                          1/2       CrashLoopBackOff   5          5m
[root@host2 ~]# kubectl delete pod -n kube-system calico-node-rh2kd
pod "calico-node-rh2kd" deleted

等待calico Pod重建

[root@host2 ~]# kubectl get pod -n kube-system
NAME                                       READY     STATUS    RESTARTS   AGE
calico-kube-controllers-5f47974799-ttz7s   1/1       Running   0          7m
calico-node-274q9                          2/2       Running   0          40m
calico-node-9th4r                          2/2       Running   0          12s
calico-node-dp8dz                          2/2       Running   0          40m