安装CFSSL

curl -s -L -o /bin/cfssl https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
curl -s -L -o /bin/cfssljson https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
curl -s -L -o /bin/cfssl-certinfo https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
chmod +x /bin/cfssl*

容器相关证书类型

client certificate： 用于服务端认证客户端,例如etcdctl、etcd proxy、fleetctl、docker客户端
server certificate: 服务端使用，客户端以此验证服务端身份,例如docker服务端、kube-apiserver
peer certificate: 双向证书，用于etcd集群成员间通信

创建CA证书

生成默认CA配置

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

修改ca-config.json,分别配置针对三种不同证书类型的profile,其中有效期43800h为5年

{
    "signing": {
        "default": {
            "expiry": "43800h"
        },
        "profiles": {
            "server": {
                "expiry": "43800h",
                "usages": [
                    "signing",
                    "key encipherment",
                    "server auth"
                ]
            },
            "client": {
                "expiry": "43800h",
                "usages": [
                    "signing",
                    "key encipherment",
                    "client auth"
                ]
            },
            "peer": {
                "expiry": "43800h",
                "usages": [
                    "signing",
                    "key encipherment",
                    "server auth",
                    "client auth"
                ]
            }
        }
    }
}

修改ca-csr.config

{
    "CN": "Self Signed Ca",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "SH",
            "O": "Netease",
            "ST": "SH",            
            "OU": "OT"
        }    ]
}

生成CA证书和私钥

cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
生成ca.pem、ca.csr、ca-key.pem(CA私钥,需妥善保管)

签发Server Certificate

cfssl print-defaults csr > server-csr.json

vim server-csr.json
{
    "CN": "Server",
    "hosts": [
        "192.168.1.1"
       ],
    "key": {
        "algo": "ecdsa",
        "size": 256
    },
    "names": [
        {
            "C": "CN",
            "L": "SH",
            "ST": "SH"
        }
    ]
}

生成服务端证书和私钥

cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json | cfssljson -bare server

签发Client Certificate

cfssl print-defaults csr > admin-csr.json

vim admin-csr.json
{
    "CN": "Client",
    "hosts": [],
    "key": {
        "algo": "ecdsa",
        "size": 256
    },
    "names": [
        {
            "C": "CN",
            "L": "SH",
            "ST": "SH"
        }
    ]
}

生成客户端证书和私钥

cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes admin-csr.json | cfssljson -bare admin

签发peer certificate

cfssl print-defaults csr > kube-proxy-csr.json
vim kube-proxy-csr.json
{
    "CN": "member1",
    "hosts": [
        "192.168.1.1"
    ],
    "key": {
        "algo": "ecdsa",
        "size": 256
    },
    "names": [
        {
            "C": "CN",
            "L": "SH",
            "ST": "SH"
        }
    ]
}

为节点member1生成证书和私钥:

cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy

针对etcd服务,每个etcd节点上按照上述方法生成相应的证书和私钥

最后校验证书

校验生成的证书是否和配置相符

openssl x509 -in ca.pem -text -noout
openssl x509 -in server.pem -text -noout
openssl x509 -in client.pem -text -noout

转自：http://blog.simlinux.com/archives/1953.html