【從零開始安裝kubernetes-1.7.3】1.環境說明以及etcd配置（CA認證）

1.環境說明

主機名	ip	說明
master-123(複用node)	192.168.116.123	etcd flannel kube-apiserver kube-controller-manager kube-scheduler kubelet kube-proxy
node-124	192.168.116.124	flannel kubelet kube-proxy

因爲目前只有2臺機器，etcd集羣因爲競選緣由至少須要奇數臺機器才能穩定運行，因此目前暫時使用1臺機器安裝etcd。

2.初始化環境（修改主機名）

192.168.116.123執行：hostnamectl --static set-hostname master-123
192.168.116.124執行：hostnamectl --static set-hostname node-124

編輯 /etc/hosts文件，配置hostname通訊

vi /etc/hosts

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.116.123 master-123
192.168.116.124 node-124

3.使用cfssl建立CA證書並分發證書

3.1 安裝cfssl

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

3.2 CA證書配置

配置config.json文件

{
"signing": {
    "default": {
        "expiry": "87600h"
    },
    "profiles": {
        "kubernetes": {
            "usages": [
                "signing",
                "key encipherment",
                "server auth",
                "client auth"
            ],
            "expiry": "87600h"
        }
    }
}
}

配置csr.json文件

{
"CN": "kubernetes",
"key": {
    "algo": "rsa",
    "size": 2048
},
"names": [
    {
        "C": "CN",
        "ST": "ShangHai",
        "L": "ShangHai",
        "O": "k8s",
        "OU": "System"
    }
]
}

3.3 生成CA證書以及私鑰

mkdir –p /opt/ssl
cd /opt/ssl

執行：cfssl gencert -initca csr.json | cfssljson -bare ca

[root@localhost ssl]# ls -ltr
total 20
-rw-r--r--. 1 root root  387 Jul 27 15:01 config.json
-rw-r--r--. 1 root root  267 Jul 27 15:04 csr.json
-rw-r--r--. 1 root root 1363 Jul 27 15:07 ca.pem
-rw-------. 1 root root 1675 Jul 27 15:07 ca-key.pem
-rw-r--r--. 1 root root 1005 Jul 27 15:07 ca.csr

3.4 分發證書

建立證書目錄

mkdir -p /etc/kubernetes/ssl

拷貝全部文件至目錄下

cp * /etc/kubernetes/ssl/

將文件拷貝至全部k8s機器上

scp * root@192.168.116.124:/etc/kubernetes/ssl/

4.安裝etcd並配置CA認證

etcd做爲一個高可用鍵值存儲系統，天生就是爲集羣化而設計的。因爲Raft算法在作決策時須要多數節點的投票，因此etcd通常部署集羣推薦奇數個節點，推薦的數量爲三、5或者7個節點構成一個集羣。

上傳文件：etcd-3.1.7-1.el7.x86_64.rpm
執行命令：rpm -ivh etcd-3.1.7-1.el7.x86_64.rpm
下載地址：http://www.rpmfind.net/linux/...

4.1 安裝etcd證書

如今只在單matser上建立etcd，以後etcd會添加2個節點

cd /opt/ssl
vi etcd-csr.json
{
  "CN": "etcd",
  "hosts": [
    "127.0.0.1",
    "192.168.116.123",
    "192.168.116.124",
    "192.168.116.120",
    "192.168.116.123",
    "192.168.116.124",
    "192.168.116.125",
    "192.168.116.120"
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "ShangHai",
      "L": "ShangHai",
      "O": "k8s",
      "OU": "System"
    }
  ]
}

上面配置文件的ip儘可能包括全部etcd節點的ip，不然須要從新分發證書
生成etcd密鑰

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

查看生成

[root@localhost ssl]# ls -ltr etcd*
-rw-r--r--. 1 root root  295 Jul 27 15:22 etcd-csr.json
-rw-r--r--. 1 root root 1440 Jul 27 15:24 etcd.pem
-rw-------. 1 root root 1679 Jul 27 15:24 etcd-key.pem
-rw-r--r--. 1 root root 1066 Jul 27 15:24 etcd.csr

拷貝到etcd服務器

cp etcd* /etc/kubernetes/ssl/
scp etcd* root@198.15.5.28:/etc/kubernetes/ssl
scp etcd* root@198.15.5.29:/etc/kubernetes/ssl

若是 etcd 非 root 用戶，讀取證書會提示沒權限
在每一臺ETCD節點上運行

chmod 644 /etc/kubernetes/ssl/etcd-key.pem

4.2 配置etcd服務

vi /usr/lib/systemd/system/etcd.service

[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
WorkingDirectory=/var/lib/etcd/
User=etcd
# set GOMAXPROCS to number of processors
ExecStart=/usr/bin/etcd \
  --name=etcd1 \
  --cert-file=/etc/kubernetes/ssl/etcd.pem \
  --key-file=/etc/kubernetes/ssl/etcd-key.pem \
  --peer-cert-file=/etc/kubernetes/ssl/etcd.pem \
  --peer-key-file=/etc/kubernetes/ssl/etcd-key.pem \
  --trusted-ca-file=/etc/kubernetes/ssl/ca.pem \
  --peer-trusted-ca-file=/etc/kubernetes/ssl/ca.pem \
  --initial-advertise-peer-urls=https://192.168.116.123:2380 \
  --listen-peer-urls=https://192.168.116.123:2380 \
  --listen-client-urls=https://192.168.116.123:2379,http://127.0.0.1:2379 \
  --advertise-client-urls=https://192.168.116.123:2379 \
  --initial-cluster-token=k8s-etcd-cluster \
  --initial-cluster=etcd1=https://192.168.116.123:2380 \
  --initial-cluster-state=new \
  --data-dir=/var/lib/etcd
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

若是是多臺etcd，應根據各節點ip的不一樣修改ip，--initial-cluster=etcd1=https://192.168.116.123:2380應該爲全部節點而不是單個節點。

4.3 全部主機關閉防火牆

關閉全部節點主機防火牆
關閉防火牆開機自啓動：systemctl disable firewalld
關閉防火牆： systemctl stop firewalld

啓動etcd：

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

4.4 驗證etcd集羣狀態

etcdctl --endpoints=https://192.168.116.123:2379 \
        --cert-file=/etc/kubernetes/ssl/etcd.pem \
        --ca-file=/etc/kubernetes/ssl/ca.pem \
        --key-file=/etc/kubernetes/ssl/etcd-key.pem \
        cluster-health

etcdctl --endpoints=https://192.168.116.123:2379 \
    --cert-file=/etc/kubernetes/ssl/etcd.pem \
    --ca-file=/etc/kubernetes/ssl/ca.pem \
    --key-file=/etc/kubernetes/ssl/etcd-key.pem \
    member list

晚上回去更新第二篇：

【從零開始安裝kubernetes-1.7.3】2.flannel、docker以及Harbor的配置以及做用