第二篇（二进制部署k8s集群—etcd集群搭建）

本文etcd集群用三台centos7搭建完成。 etcd1：192.168.206.31 etcd2：192.168.206.32 etcd3：192.168.206.33

一、创建CA证书和密钥，下面步骤是在k8s-master1上操作的。 1、所有机器上创建相关目录

mkdir -p /opt/kubernetes/{bin,ssl,yaml,conf,log,cfg}
echo 'export PATH=$PATH:/opt/kubernetes/bin' >> /etc/profile
source /etc/profile

2、下载cfssl

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

3、创建证书签发机构CA，先创建一个证书制作的文件夹。

mkdir -p /data/ssl
cd /data/ssl

cat > ca-config.json <<EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
        "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ],
        "expiry": "87600h"
      }
    }
  }
}
EOF

ca-config.json：可以定义多个 profiles，分别指定不同的过期时间、使用场景等参数；后续在签名证书时使用某个 profile；
signing：表示该证书可用于签名其它证书；生成的 ca.pem 证书中 CA=TRUE；
server auth：表示 client 可以用该 CA 对 server 提供的证书进行验证；
client auth：表示 server 可以用该 CA 对 client 提供的证书进行验证；

4、创建CA证书签名请求

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

CN：Common Name，kube-apiserver 从证书中提取该字段作为请求的用户名 (User Name)，浏览器使用该字段验证网站是否合法；
O：Organization，kube-apiserver 从证书中提取该字段作为请求用户所属的组 (Group)；
kube-apiserver 将提取的 User、Group 作为 RBAC 授权的用户标识；

6、生成 CA 证书和私钥：

cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
[root@master1 ssl]# ls
ca-config.json  ca.csr  ca-csr.json  ca-key.pem  ca.pem

创建存放etcd证书文件夹
mkdir /opt/kubernetes/ssl/etcd/
cp *.pem /opt/kubernetes/ssl/

7、创建 etcd 证书签名请求，先创建一个制作证书的文件夹

mkdir /data/ssl/etcd
cd /data/ssl/etcd

cat > etcd-csr.json <<EOF
{
    "CN": "etcd",
    "hosts": [
      "192.168.206.31",
      "192.168.206.32",
      "192.168.206.33"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "hangzhou",
            "ST": "Zhejiang",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
EOF

8、生成etcd证书和对应的私钥

cfssl gencert -ca=/data/ssl/ca.pem 
-ca-key=/data/ssl/ca-key.pem 
-config=/data/ssl/ca-config.json 
-profile=kubernetes etcd-csr.json 
| cfssljson -bare etcd


cp *.pem /opt/kubernetes/ssl/etcd

注意：证书3哥etcd都要放哦。

ETCD使用证书的组件如下： etcd：使用 ca.pem、etcd-key.pem、etcd.pem；

二、部署etcd集群 1、下载etcd安装包

wget https://github.com/etcd-io/etcd/releases/download/v3.3.10/etcd-v3.3.10-linux-amd64.tar.gz
tar zxf etcd-v3.3.10-linux-amd64.tar.gz
cp  etcd-v3.3.10-linux-amd64/etcd* /opt/kubernetes/bin/

2、创建工作目录

mkdir /opt/kubernetes/etcd

3、创建systemd unit 文件(修改对应etcd主机名称和ip)

cat > /etc/systemd/system/etcd.service << EOF
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target
Documentation=https://github.com/coreos

[Service]
Type=notify
WorkingDirectory=/opt/kubernetes/etcd/
ExecStart=/opt/kubernetes/bin/etcd 
  --name etcd1 
  --cert-file=/opt/kubernetes/ssl/etcd/etcd.pem 
  --key-file=/opt/kubernetes/ssl/etcd/etcd-key.pem 
  --peer-cert-file=/opt/kubernetes/ssl/etcd/etcd.pem 
  --peer-key-file=/opt/kubernetes/ssl/etcd/etcd-key.pem 
  --trusted-ca-file=/opt/kubernetes/ssl/etcd/ca.pem 
  --peer-trusted-ca-file=/opt/kubernetes/ssl/etcd/ca.pem 
  --initial-advertise-peer-urls https://192.168.206.31:2380 
  --listen-peer-urls https://192.168.206.31:2380 
  --listen-client-urls https://192.168.206.31:2379,http://127.0.0.1:2379 
  --advertise-client-urls https://192.168.206.31:2379 
  --initial-cluster-token etcd-cluster-0 
  --initial-cluster etcd1=https://192.168.206.31:2380,etcd2=https://192.168.206.32:2380,etcd3=https://192.168.206.33:2380 
  --initial-cluster-state new 
  --data-dir=/opt/kubernetes/etcd
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF


为了保证通信安全，需要指定 etcd 的公私钥(cert-file和key-file)、Peers 通信的公私钥和 CA 证书(peer-cert-file、peer-key-file、peer-trusted-ca-file)、客户端的CA证书(trusted-ca-file)； 

创建etcd.pem 证书时使用的 etcd-csr.json 文件的 hosts 字段包含所有 etcd 节点的IP，否则证书校验会出错；
–initial-cluster-state 值为 new 时，–name 的参数值必须位于 –initial-cluster 列表中.

4、启动etcd服务并且设置开机自启动

systemctl daemon-reload
systemctl start etcd.service
systemctl status etcd.service
systemctl enable etcd.service

最先启动的 etcd 进程会卡住一段时间，等待其它节点上的 etcd 进程加入集群，为正常现象。

5、验证etcd集群状态，以及查看leader,在任何一个etcd节点执行

[root@k8s-master1 etcd]# etcdctl --ca-file=/opt/kubernetes/ssl/etcd/ca.pem --cert-file=/opt/kubernetes/ssl/etcd/etcd.pem --key-file=/opt/kubernetes/ssl/etcd/etcd-key.pem cluster-health
member 8b7aa04311a7389f is healthy: got healthy result from https://192.168.206.32:2379
member 9b7dcd0eef5c1758 is healthy: got healthy result from https://192.168.206.33:2379
member f617b05c8dbf5231 is healthy: got healthy result from https://192.168.206.31:2379
cluster is healthy
[root@k8s-master1 etcd]# etcdctl --ca-file=/opt/kubernetes/ssl/etcd/ca.pem --cert-file=/opt/kubernetes/ssl/etcd/etcd.pem --key-file=/opt/kubernetes/ssl/etcd/etcd-key.pem member list
8b7aa04311a7389f: name=etcd2 peerURLs=https://192.168.206.32:2380 clientURLs=https://192.168.206.32:2379 isLeader=false
9b7dcd0eef5c1758: name=etcd3 peerURLs=https://192.168.206.33:2380 clientURLs=https://192.168.206.33:2379 isLeader=true
f617b05c8dbf5231: name=etcd1 peerURLs=https://192.168.206.31:2380 clientURLs=https://192.168.206.31:2379 isLeader=false

至此ETCD TLS证书集群部署完成