[k8s] 重新加入master节点

待我称王封你为后i 2022-09-09 11:53 239阅读 0赞

> 默认token的有效期为24小时，当过期之后，该token就不可用了，  
> 如果后续有nodes节点加入，解决方法如下：

## 重新生成新的token ##

kubeadm token create
    [root@k8s-master ~]# kubeadm token create
    0w3a92.ijgba9ia0e3scicg
    [root@k8s-master ~]# kubeadm token list
    TOKEN                     TTL       EXPIRES                     USAGES                   DESCRIPTION                                                EXTRA GROUPS
    0w3a92.ijgba9ia0e3scicg   23h       2019-09-08T22:02:40+08:00   authentication,signing   <none>                                                     system:bootstrappers:kubeadm:default-node-token
    t0ehj8.k4ef3gq0icr3etl0   22h       2019-09-08T20:58:34+08:00   authentication,signing   The default bootstrap token generated by 'kubeadm init'.   system:bootstrappers:kubeadm:default-node-token
    [root@k8s-master ~]#

## 获取ca证书sha256编码hash值 ##

[root@k8s-master ~]# openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'
    ce07a7f5b259961884c55e3ff8784b1eda6f8b5931e6fa2ab0b30b6a4234c09a

–token：用于Master验证Node身份。  
要想集群首次引导启动时，支持bootstrap-token验证，APIServer需要开启下面的配置选项：  
　　--enable-bootstrap-token-auth=true

kubectl get secret -n kube-system|grep bootstrap-token
    bootstrap-token-nh819o                           bootstrap.kubernetes.io/token         7         2d

nh819o是token的id。pzcpohatm7p3a5cm是secret。  
当kubeadm join访问APIServer，会在请求的header中携带这一token。APIServer会根据token进行身份验证。  
API会查询是否有bootstrap-token的前缀的secret对象。  
我们可以查看secret对象的内容。

kubectl get secret/bootstrap-token-nh819o -n kube-system -o yamlapiVersion: v1
    data:
      auth-extra-groups: c3lzdGVtOmJvb3RzdHJhcHBlcnM6a3ViZWFkbTpkZWZhdWx0LW5vZGUtdG9rZW4=
      description: VGhlIGRlZmF1bHQgYm9vdHN0cmFwIHRva2VuIGdlbmVyYXRlZCBieSAna3ViZWFkbSBpbml0Jy4=
      expiration: MjAxOS0wNi0yMFQxMToyNDoyOCswODowMA==
      token-id: bmg4MTlv
      token-secret: cHpjcG9oYXRtN3AzYTVjbQ==
      usage-bootstrap-authentication: dHJ1ZQ==
      usage-bootstrap-signing: dHJ1ZQ==
    kind: Secret
    metadata:
      creationTimestamp: 2019-06-19T03:24:28Z
      name: bootstrap-token-nh819o
      namespace: kube-system
      resourceVersion: "160"
      selfLink: /api/v1/namespaces/kube-system/secrets/bootstrap-token-nh819o
      uid: bea32cfa-9241-11e9-a613-52540095a842
    type: bootstrap.kubernetes.io/token

对token-secret进行解码：

echo cHpjcG9oYXRtN3AzYTVjbQ==|base64 -d
    pzcpohatm7p3a5cm

这个与token参数的secret值一致。

## 节点加入集群 ##

[root@k8s-node01 ~]# kubeadm join --token aa78f6.8b4cafc8ed26c34f --discovery-token-ca-cert-hash sha256:0fd95a9bc67a7bf0ef42da968a0d55d92e52898ec37c971bd77ee501d845b538 192.168.73.138:6443 --skip-preflight-check=true

–discovery-token-ca-cert-hash：用于Node验证master身份。  
执行join时，API Server会下发ca.crt，这个证书会被node存放在/etc/kubernetes/pki目录下。  
然后kubeadm join再用ca设置公钥证书的hash值，与discovery-token-ca-cert-hash的值进行比对。

# k8s执行 kubeadm join 加入node节点超时，报错\[kubelet-check\] Initial timeout of 40s passed. #

kubeadm join 172.28.18.69:6443 --token abcdef.0123456789abcdef     --discovery-token-ca-cert-hash sha256:6010baa60fc234e60cb353a54b4179afd3205cd6b4fc15f415117a77b6d8ac07
    W0109 18:03:24.343831   16537 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set.
    [preflight] Running pre-flight checks
    [preflight] Reading configuration from the cluster...
    [preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
    [kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.18" ConfigMap in the kube-system namespace
    [kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
    [kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
    [kubelet-start] Starting the kubelet
    [kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...
    [kubelet-check] Initial timeout of 40s passed.
    error execution phase kubelet-start: error uploading crisocket: timed out waiting for the condition
    To see the stack trace of this error execute with --v=5 or higher

> 显示超时，加入节点失败

## node节点执行 ##

kubeadm reset -f

## 再执行加入 ##

kubeadm join 172.28.18.69:6443 --token abcdef.0123456789abcdef     --discovery-token-ca-cert-hash sha256:6010baa60fc234e60cb353a54b4179afd3205cd6b4fc15f415117a77b6d8ac07