Kubernetes安装之三：etcd集群的配置

为什么要首先配置etcd集群呢，因为etcd集群是Kubernetes的基础，所有数据都存储在这里

1.生成etcd证书 

其实这里建议使用主机名，避免ip变化而导致的数据库不可用,但是我习惯用ip，为避免证书看起来不那么乱，所以我将不同的证书放置到不同的目录里面

cat > /etc/ssl/etcd/etcd-csr.json <<EOF
{
  "CN": "etcd",
  "hosts": [
    "127.0.0.1",
    "192.168.1.40",
    "192.168.1.41",
    "192.168.1.42"
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "ChengDu",
      "L": "ChengDu",
      "O": "k8s",
      "OU": "dessler"
    }
  ]
}
EOF

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

ls
etcd.csr  etcd-csr.json  etcd-key.pem  etcd.pem

2.分发证书及二进制文件

过程我就省略了，都是些基本的文件传输操作

3.准备证书环境

（自己注意数据保存目录，根据自己的情况决定）

chmod 644 /etc/ssl/etcd/etcd-key.pem
useradd -s /sbin/nologin -M etcd
mkdir -p /var/lib/etcd/
chown -R etcd:etcd /var/lib/etcd/

4.配置etcd的服务

这里需要特别注意就是etcd的名字，集群的3个节点是不能重复的，还有和这个名字和集群的配置（比如我这里的etcd01，etcd02，etcd03）

4.1服务器a配置etcd服务

cat > /usr/lib/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]
User=etcd
Type=notify
WorkingDirectory=/var/lib/etcd/
ExecStart=/usr/bin/etcd \\
  --data-dir=/var/lib/etcd \\
  --name=etcd01 \\
  --cert-file=/etc/ssl/etcd/etcd.pem \\
  --key-file=/etc/ssl/etcd/etcd-key.pem \\
  --trusted-ca-file=/etc/ssl/ca.pem \\
  --peer-cert-file=/etc/ssl/etcd/etcd.pem \\
  --peer-key-file=/etc/ssl/etcd/etcd-key.pem \\
  --peer-trusted-ca-file=/etc/ssl/ca.pem \\
  --peer-client-cert-auth \\
  --client-cert-auth \\
  --listen-peer-urls=https://192.168.1.40:2380 \\
  --initial-advertise-peer-urls=https://192.168.1.40:2380 \\
  --listen-client-urls=https://192.168.1.40:2379,http://127.0.0.1:2379 \\
  --advertise-client-urls=https://192.168.1.40:2379 \\
  --initial-cluster-token=etcd-cluster-0 \\
  --initial-cluster=etcd01=https://192.168.1.40:2380,etcd02=https://192.168.1.41:2380,etcd03=https://192.168.1.42:2380 \\
  --initial-cluster-state=new
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

4.2服务器a配置etcd服务

cat > /usr/lib/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]
User=etcd
Type=notify
WorkingDirectory=/var/lib/etcd/
ExecStart=/usr/bin/etcd \\
  --data-dir=/var/lib/etcd \\
  --name=etcd02 \\
  --cert-file=/etc/ssl/etcd/etcd.pem \\
  --key-file=/etc/ssl/etcd/etcd-key.pem \\
  --trusted-ca-file=/etc/ssl/ca.pem \\
  --peer-cert-file=/etc/ssl/etcd/etcd.pem \\
  --peer-key-file=/etc/ssl/etcd/etcd-key.pem \\
  --peer-trusted-ca-file=/etc/ssl/ca.pem \\
  --peer-client-cert-auth \\
  --client-cert-auth \\
  --listen-peer-urls=https://192.168.1.41:2380 \\
  --initial-advertise-peer-urls=https://192.168.1.41:2380 \\
  --listen-client-urls=https://192.168.1.41:2379,http://127.0.0.1:2379 \\
  --advertise-client-urls=https://192.168.1.41:2379 \\
  --initial-cluster-token=etcd-cluster-0 \\
  --initial-cluster=etcd01=https://192.168.1.40:2380,etcd02=https://192.168.1.41:2380,etcd03=https://192.168.1.42:2380 \\
  --initial-cluster-state=new
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

4.3服务器a配置etcd服务

cat > /usr/lib/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]
User=etcd
Type=notify
WorkingDirectory=/var/lib/etcd/
ExecStart=/usr/bin/etcd \\
  --data-dir=/var/lib/etcd \\
  --name=etcd03 \\
  --cert-file=/etc/ssl/etcd/etcd.pem \\
  --key-file=/etc/ssl/etcd/etcd-key.pem \\
  --trusted-ca-file=/etc/ssl/ca.pem \\
  --peer-cert-file=/etc/ssl/etcd/etcd.pem \\
  --peer-key-file=/etc/ssl/etcd/etcd-key.pem \\
  --peer-trusted-ca-file=/etc/ssl/ca.pem \\
  --peer-client-cert-auth \\
  --client-cert-auth \\
  --listen-peer-urls=https://192.168.1.42:2380 \\
  --initial-advertise-peer-urls=https://192.168.1.42:2380 \\
  --listen-client-urls=https://192.168.1.42:2379,http://127.0.0.1:2379 \\
  --advertise-client-urls=https://192.168.1.42:2379 \\
  --initial-cluster-token=etcd-cluster-0 \\
  --initial-cluster=etcd01=https://192.168.1.40:2380,etcd02=https://192.168.1.41:2380,etcd03=https://192.168.1.42:2380 \\
  --initial-cluster-state=new
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

5.检查集群状态

etcdctl --endpoints=https://192.168.1.40:2379,https://192.168.1.41:2379,https://192.168.1.42:2379 \
>         --cert-file=/etc/ssl/etcd/etcd.pem \
>         --ca-file=/etc/ssl/ca.pem \
>         --key-file=/etc/ssl/etcd/etcd-key.pem \
>         cluster-health
member e42b05792291d17 is healthy: got healthy result from https://192.168.1.41:2379
member 68326dea8aa5233d is healthy: got healthy result from https://192.168.1.40:2379
member e10fc861b3b13bc0 is healthy: got healthy result from https://192.168.1.42:2379

注意的几个地方：name 需要一一对应，ip地址也容易出错

集群状态正常，etd集群创建成果

• 说明：
• User：指定以 k8s 账户运行
• WorkingDirectory、--data-dir：指定工作目录和数据目录为/var/lib/etcd，需在启动服务前创建这个目录
• --name：指定节点名称，当--initial-cluster-state 值为 new 时，--name 的参数值必须位于 --initial-cluster 列表中
• --cert-file、--key-file：etcd server 与 client 通信时使用的证书和私钥
• --trusted-ca-file：签名 client 证书的 CA 证书，用于验证 client 证书
• --peer-cert-file、--peer-key-file：etcd 与 peer 通信使用的证书和私钥
• --peer-trusted-ca-file：签名 peer 证书的 CA 证书，用于验证 peer 证书