搭建kubernetes高可用集群-02创建TLS证书和密钥

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创建TLS证书和密钥

安装CFSSL

wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
chmod +x cfssl_linux-amd64
mv cfssl_linux-amd64 /usr/local/bin/cfssl

wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
chmod +x cfssljson_linux-amd64
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson

wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
chmod +x cfssl-certinfo_linux-amd64
mv cfssl-certinfo_linux-amd64 /usr/local/bin/cfssl-certinfo

创建CA

创建CA配置文件

mkdir /root/ssl
cd /root/ssl
cfssl print-defaults config > config.json
cfssl print-defaults csr > csr.json

# 根据config.json文件的格式创建如下的ca-config.json文件
# 过期时间设置成了 87600h
cat > ca-config.json <<EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
        "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ],
        "expiry": "87600h"
      }
    }
  }
}
EOF

创建CA证书签名请求

创建 ca-csr.json 文件，内容如下：

cat > ca-csr.json << EOF
{
  "CN": "kubernetes",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "Shenzhen",
      "L": "Shenzhen",
      "O": "k8s",
      "OU": "System"
    }
  ],
    "ca": {
       "expiry": "87600h"
    }
}
EOF

生成CA证书和私钥

cfssl gencert -initca ca-csr.json | cfssljson -bare ca
ls ca*
ca-config.json  ca.csr  ca-csr.json  ca-key.pem  ca.pem

创建kubernetes证书

  • 创建kubernetes证书签名请求文件
    创建 kubernetes 证书签名请求文件 kubernetes-csr.json
cat > kubernetes-csr.json << EOF
{
    "CN": "kubernetes",
    "hosts": [
      "127.0.0.1",
      "192.168.255.194",
      "192.168.255.195",
      "192.168.255.196",
      "192.168.255.190",
      "192.168.255.191",
      "192.168.255.192",
      "192.168.255.200",
      "192.168.255.201",
      "192.168.255.202",
      "192.168.255.199",
      "192.168.255.198",
      "192.168.255.197",
      "10.254.0.1",
      "kubernetes",
      "kubernetes.default",
      "kubernetes.default.svc",
      "kubernetes.default.svc.cluster",
      "kubernetes.default.svc.cluster.local"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "ST": "Shenzhen",
            "L": "Shenzhen",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
EOF
  • 生成 kubernetes 证书和私钥
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kubernetes-csr.json | cfssljson -bare kubernetes

ls kubernetes*

创建Admin证书

  • 创建Admin证书签名请求文件
cat > admin-csr.json << EOF
{
  "CN": "admin",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "Shenzhen",
      "L": "Shenzhen",
      "O": "system:masters",
      "OU": "System"
    }
  ]
}
EOF
  • 生成admin证书和私钥
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes admin-csr.json | cfssljson -bare admin
ls admin*

创建kube-proxy证书

  • 创建kube-proxy证书签名请求文件
cat > kube-proxy-csr.json << EOF
{
  "CN": "system:kube-proxy",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "Shenzhen",
      "L": "Shenzhen",
      "O": "k8s",
      "OU": "System"
    }
  ]
}
EOF
  • 生成kube-proxy客户端证书和私钥
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes  kube-proxy-csr.json | cfssljson -bare kube-proxy

校验证书

  • 使用opsnssl命令验证: openssl x509 -noout -text -in kubernetes.pem
  • 使用cfssl-certinfo命令: cfssl-certinfo -cert kubernetes.pem

分发证书

到现在我们已经生成的证书文件有：

[root@master script]# ls /etc/kubernetes/ssl/
admin-key.pem  admin.pem  ca-key.pem  ca.pem  kube-proxy-key.pem  kube-proxy.pem  kubernetes-key.pem  kubernetes.pem

接下来将生成的证书和秘钥文件（后缀名为.pem）拷贝到对应机器的 /etc/kubernetes/ssl 目录下备用；
各组件所需要证书文件如下：

组件 所需证书文件
etcd ca.pem、kubernetes-key.pem、kubernetes.pem
apiserver ca.pem、kubernetes-key.pem、kubernetes.pem
master admin-key.pem、admin.pem 、ca-key.pem、 ca.pem
node ca.pem、kube-proxy-key.pem、kube-proxy.pem

etcd 节点上共用kubernetes的证书文件

复制对应证书到各组件节点上

mkdir -p /etc/kubernetes/ssl
cp *.pem /etc/kubernetes/ssl

参考： jimmysong博客

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