Kubernetes m6S之SSL证书时效查看

 

如何修改Kubernetes的SSL证书有效期

 

主机配置规划

服务器名称(hostname)系统版本配置内网IP外网IP(模拟)
k8s-masterCentOS7.72C/4G/20G172.16.1.11010.0.0.110
k8s-node01CentOS7.72C/4G/20G172.16.1.11110.0.0.111
k8s-node02CentOS7.72C/4G/20G172.16.1.11210.0.0.112

 

为什么要修改证书有效期

Kubernetes默认的证书有效期都是1年，因此需要我们每年都更新证书，显然这对我们实际生产环境来说是很不友好的；因此我们要对Kubernetes的SSL证书有效期进行修改。

证书有效期查看

 1 [root@k8s-master pki]# pwd
 2 /etc/kubernetes/pki
 3 [root@k8s-master pki]# ll
 4 total 56
 5 -rw-r--r-- 1 root root 1224 May 1215:51 apiserver.crt
 6 -rw-r--r-- 1 root root 1090 May 1215:51 apiserver-etcd-client.crt
 7 -rw------- 1 root root 1675 May 1215:51 apiserver-etcd-client.key
 8 -rw------- 1 root root 1675 May 1215:51 apiserver.key
 9 -rw-r--r-- 1 root root 1099 May 1215:51 apiserver-kubelet-client.crt
10 -rw------- 1 root root 1675 May 1215:51 apiserver-kubelet-client.key
11 -rw-r--r-- 1 root root 1025 May 1215:51 ca.crt
12 -rw------- 1 root root 1675 May 1215:51 ca.key
13 drwxr-xr-x 2 root root  162 May 1215:51 etcd
14 -rw-r--r-- 1 root root 1038 May 1215:51 front-proxy-ca.crt
15 -rw------- 1 root root 1675 May 1215:51 front-proxy-ca.key
16 -rw-r--r-- 1 root root 1058 May 1215:51 front-proxy-client.crt
17 -rw------- 1 root root 1675 May 1215:51 front-proxy-client.key
18 -rw------- 1 root root 1679 May 1215:51 sa.key
19 -rw------- 1 root root  451 May 1215:51 sa.pub
20 [root@k8s-master pki]#
21 [root@k8s-master pki]# for i in $(ls *.crt); doecho"===== $i ====="; openssl x509 -in $i -text -noout | grep -A 3'Validity' ; done
22 ===== apiserver.crt =====
23        Validity
24             Not Before: May 1207:51:362020 GMT
25             Not After : May 1207:51:362021 GMT
26         Subject: CN=kube-apiserver
27 ===== apiserver-etcd-client.crt =====
28        Validity
29             Not Before: May 1207:51:372020 GMT
30             Not After : May 1207:51:382021 GMT
31         Subject: O=system:masters, CN=kube-apiserver-etcd-client
32 ===== apiserver-kubelet-client.crt =====
33        Validity
34             Not Before: May 1207:51:362020 GMT
35             Not After : May 1207:51:372021 GMT
36         Subject: O=system:masters, CN=kube-apiserver-kubelet-client
37 ===== ca.crt =====
38        Validity
39             Not Before: May 1207:51:362020 GMT
40             Not After : May 1007:51:362030 GMT
41         Subject: CN=kubernetes
42 ===== front-proxy-ca.crt =====
43        Validity
44             Not Before: May 1207:51:372020 GMT
45             Not After : May 1007:51:372030 GMT
46         Subject: CN=front-proxy-ca
47 ===== front-proxy-client.crt =====
48        Validity
49             Not Before: May 1207:51:372020 GMT
50             Not After : May 1207:51:372021 GMT
51         Subject: CN=front-proxy-client
52 [root@k8s-master pki]#

由上可见，除了ca根证书，其他证书有效期都是1年。

 

证书有效时限修改

go环境部署

go语言中文网

https://studygolang.com/

 

 

在Linux命令行下载

1 [root@k8s-master software]# wget https://studygolang.com/dl/golang/go1.14.6.linux-amd64.tar.gz
2 [root@k8s-master software]# tar xf go1.14.6.linux-amd64.tar.gz -C /usr/local/
3 [root@k8s-master software]# vim /etc/profile   # 最后面添加如下信息
4# go语言环境变量
5 export PATH=$PATH:/usr/local/go/bin
6 [root@k8s-master software]# source /etc/profile

 

Kubernetes源码下载与更改证书策略

当期k8s版本

1 [root@k8s-master software]# kubectl version
2 Client Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.4", GitCommit:"8d8aa39598534325ad77120c120a22b3a990b5ea", GitTreeState:"clean", BuildDate:"2020-03-12T21:03:42Z", GoVersion:"go1.13.8", Compiler:"gc", Platform:"linux/amd64"}
3 Server Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.4", GitCommit:"8d8aa39598534325ad77120c120a22b3a990b5ea", GitTreeState:"clean", BuildDate:"2020-03-12T20:55:23Z", GoVersion:"go1.13.8", Compiler:"gc", Platform:"linux/amd64"}

 

根据k8s版本下载源码

 

操作步骤

 1 [root@k8s-master software]# wget https://github.com/kubernetes/kubernetes/archive/v1.17.4.tar.gz
 2 [root@k8s-master software]# tar xf v1.17.4.tar.gz && cd kubernetes-1.17.4
 3 [root@k8s-master kubernetes-1.17.4]# vim cmd/kubeadm/app/util/pkiutil/pki_helpers.go
 4………………
 5 func NewSignedCert(cfg *certutil.Config, key crypto.Signer, caCert *x509.Certificate, caKey crypto.Signer) (*x509.Certificate, error) {
 6// 添加如下行 有效时间 100 年
 7         const effectyear = time.Hour * 24 * 365 * 100
 8
 9         serial, err := cryptorand.Int(cryptorand.Reader, new(big.Int).SetInt64(math.MaxInt64))
10if err != nil {
11                return nil, err
12        }
13if len(cfg.CommonName) == 0 {
14                 return nil, errors.New("must specify a CommonName")
15        }
16if len(cfg.Usages) == 0 {
17                 return nil, errors.New("must specify at least one ExtKeyUsage")
18        }
19
20         certTmpl := x509.Certificate{
21                Subject: pkix.Name{
22                        CommonName:   cfg.CommonName,
23                        Organization: cfg.Organization,
24                },
25                DNSNames:     cfg.AltNames.DNSNames,
26                IPAddresses:  cfg.AltNames.IPs,
27                SerialNumber: serial,
28                NotBefore:    caCert.NotBefore,
29// NotAfter:     time.Now().Add(kubeadmconstants.CertificateValidity).UTC(),
30                 NotAfter:     time.Now().Add(effectyear).UTC(),   // 修改行
31                 KeyUsage:     x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
32                ExtKeyUsage:  cfg.Usages,
33        }
34 [root@k8s-master kubernetes-1.17.4]#
35# 注意路径
36 [root@k8s-master kubernetes-1.17.4]# make WHAT=cmd/kubeadm GOFLAGS=-v
37# 将更新后的kubeadm拷贝到指定位置
38 [root@k8s-master kubernetes-1.17.4]# cp -a _output/bin/kubeadm /root/kubeadm-new

 

更新kubeadm并备份原证书

1# kubeadm更新
2mv /usr/bin/kubeadm /usr/bin/kubeadm_20200725
3mv /root/kubeadm-new /usr/bin/kubeadm
4chmod755 /usr/bin/kubeadm
5# 原证书备份
6cp -a /etc/kubernetes/pki/ /etc/kubernetes/pki_20200725

 

证书更新

操作如下：

 1# 证书更新
 2 [root@k8s-master ~]# kubeadm alpha certs renew all --config=/root/k8s_install/kubeadm-config.yaml
 3# 查看新证书有效期
 4 [root@k8s-master ~]# cd /etc/kubernetes/pki
 5 [root@k8s-master pki]# ll
 6 total 56
 7 -rw-r--r-- 1 root root 1224 Jul 2518:44 apiserver.crt
 8 -rw-r--r-- 1 root root 1094 Jul 2518:44 apiserver-etcd-client.crt
 9 -rw------- 1 root root 1675 Jul 2518:44 apiserver-etcd-client.key
10 -rw------- 1 root root 1679 Jul 2518:44 apiserver.key
11 -rw-r--r-- 1 root root 1103 Jul 2518:44 apiserver-kubelet-client.crt
12 -rw------- 1 root root 1679 Jul 2518:44 apiserver-kubelet-client.key
13 -rw-r--r-- 1 root root 1025 May 1215:51 ca.crt
14 -rw------- 1 root root 1675 May 1215:51 ca.key
15 drwxr-xr-x 2 root root  162 May 1215:51 etcd
16 -rw-r--r-- 1 root root 1038 May 1215:51 front-proxy-ca.crt
17 -rw------- 1 root root 1675 May 1215:51 front-proxy-ca.key
18 -rw-r--r-- 1 root root 1058 Jul 2518:44 front-proxy-client.crt
19 -rw------- 1 root root 1679 Jul 2518:44 front-proxy-client.key
20 -rw------- 1 root root 1679 May 1215:51 sa.key
21 -rw------- 1 root root  451 May 1215:51 sa.pub
22 [root@k8s-master pki]#
23 [root@k8s-master pki]# for i in $(ls *.crt); doecho"===== $i ====="; openssl x509 -in $i -text -noout | grep -A 3'Validity' ; done
24 ===== apiserver.crt =====
25        Validity
26             Not Before: May 1207:51:362020 GMT
27             Not After : Jul  110:44:202120 GMT
28         Subject: CN=kube-apiserver
29 ===== apiserver-etcd-client.crt =====
30        Validity
31             Not Before: May 1207:51:372020 GMT
32             Not After : Jul  110:44:202120 GMT
33         Subject: O=system:masters, CN=kube-apiserver-etcd-client
34 ===== apiserver-kubelet-client.crt =====
35        Validity
36             Not Before: May 1207:51:362020 GMT
37             Not After : Jul  110:44:202120 GMT
38         Subject: O=system:masters, CN=kube-apiserver-kubelet-client
39 ===== ca.crt =====
40        Validity
41             Not Before: May 1207:51:362020 GMT
42             Not After : May 1007:51:362030 GMT
43         Subject: CN=kubernetes
44 ===== front-proxy-ca.crt =====
45        Validity
46             Not Before: May 1207:51:372020 GMT
47             Not After : May 1007:51:372030 GMT
48         Subject: CN=front-proxy-ca
49 ===== front-proxy-client.crt =====
50        Validity
51             Not Before: May 1207:51:372020 GMT
52             Not After : Jul  110:44:222120 GMT
53         Subject: CN=front-proxy-client

由上可见，除了CA根证书，其他证书有效期已经改为 100 年。

 

kubeadm-config.yaml文件参见如下

 1 [root@k8s-master k8s_install]# pwd
 2 /root/k8s_install
 3 [root@k8s-master k8s_install]# kubeadm config print init-defaults > kubeadm-config.yaml
 4# 做了适当修改
 5 [root@k8s-master k8s_install]# cat kubeadm-config.yaml
 6 apiVersion: kubeadm.k8s.io/v1beta2
 7bootstrapTokens:
 8 - groups:
 9   - system:bootstrappers:kubeadm:default-node-token
10  token: abcdef.0123456789abcdef
11  ttl: 24h0m0s
12  usages:
13   - signing
14   - authentication
15kind: InitConfiguration
16localAPIEndpoint:
17  # 改为本机内网IP
18   advertiseAddress: 172.16.1.110
19   bindPort: 6443
20nodeRegistration:
21   criSocket: /var/run/dockershim.sock
22   name: k8s-master
23  taints:
24   - effect: NoSchedule
25     key: node-role.kubernetes.io/master
26 ---
27apiServer:
28  timeoutForControlPlane: 4m0s
29 apiVersion: kubeadm.k8s.io/v1beta2
30 certificatesDir: /etc/kubernetes/pki
31clusterName: kubernetes
32controllerManager: {}
33dns:
34  type: CoreDNS
35etcd:
36  local:
37     dataDir: /var/lib/etcd
38imageRepository: k8s.gcr.io
39kind: ClusterConfiguration
40 # 本次部署的版本为 v1.17.4
41 kubernetesVersion: v1.17.4
42networking:
43  dnsDomain: cluster.local
44  # 添加如下行，指定pod网络的IP地址范围，因为flannel 就是这个网段
45   podSubnet: 10.244.0.0/16
46   # 默认值即可，无需改变。服务VIP使用可选的IP地址范围。默认10.96.0.0/12
47   serviceSubnet: 10.96.0.0/12
48scheduler: {}
49 ---
50# 添加如下配置段，调度方式从默认改为ipvs方式【如果上面初始化没有做ipvs，那么这段就不需要】
51 apiVersion: kubeproxy.config.k8s.io/v1alpha1
52kind: KubeProxyConfiguration
53featureGates:
54   SupportIPVSProxyMode: true
55 mode: ipvs

 

相关阅读

1、基于kubeadm快速部署kubernetes K8S V1.17.4集群-无坑完整版

完毕！

 

 

 

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