二进制安装 kubernetes 1.12(一) - 安装 ETCD

软件环境

软件	版本
操作系统	CentOS 7.4
Docker	18-ce
Kubernetes	1.12

服务器角色

角色	IP	组件
k8s-master	192.168.0.205	kube-apiserver, kuber-controller-manager, kube-scheduler, etcd
k8s-node1	192.168.0.206	kube-let, kuber-proxy, docker, flannel, etcd
k8s-node2	192.168.0.207	kube-let, kuber-proxy, docker, flannel, etcd

架构图

在 master 上安装 ansible 管理集群

yum install ansible -y

# 配置ansible
cat > /etc/ansible/hosts <<EOF
[myhost]
192.168.0.205

[node]
192.168.0.206
192.168.0.207
EOF

# 生成无密码公私钥
cd ~
ssh-keygen -t rsa

# 复制到对应的主机
ssh-copy-id -i ~/.ssh/id_rsa.pub root@192.168.0.205
ssh-copy-id -i ~/.ssh/id_rsa.pub root@192.168.0.206
ssh-copy-id -i ~/.ssh/id_rsa.pub root@192.168.0.207

# 测试 ansible
ansible all -m ping

开放防火墙

ansible all -m shell -a 'firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="192.168.0.0/16" accept"'
ansible all -m shell -a 'firewall-cmd --reload'

生成证书

在 k8s-master 上执行

使用cfssl来生成自签证书，先下载cfssl工具：

mkdir /iba/tools -p
cd /iba/tools

wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64

chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64 

mv cfssl_linux-amd64 /usr/local/bin/cfssl
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
mv cfssl-certinfo_linux-amd64 /usr/bin/cfssl-certinfo

创建以下三个文件

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

cat > ca-csr.json <<EOF
{
  "CN": "etcd CA",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "Beijing",
      "ST": "Beijing"
    }
  ]
}
EOF

"CN"：Common Name， 组件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；

cat > server-csr.json <<EOF
{
  "CN": "etcd",
  "hosts": [
    "192.168.0.205",
    "192.168.0.206",
    "192.168.0.207"
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "BeiJing",
      "ST": "BeiJing"
    }
  ]
}
EOF

生成证书

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

# 生成了 ca.pem ca-key.pem ca.csr

ca.pem，ca-key.pem，ca.csr 组成了一个自签名的CA机构

证书名称	作用
ca.pem	CA 根证书文件
ca-key.pem	服务端私钥，用于对客户端请求的解密和签名
ca.csr	证书签名请求，用于交叉签名或重新签名

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

# 生成了 server.csr server-key.pem  server.pem

部署Etcd

cd /iba/tools
wget https://github.com/etcd-io/etcd/releases/download/v3.2.12/etcd-v3.2.12-linux-amd64.tar.gz

mkdir /opt/etcd/{bin,cfg,ssl} -p
tar zxf etcd-v3.2.12-linux-amd64.tar.gz
mv etcd-v3.2.12-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

创建etcd配置文件：

cat > /opt/etcd/cfg/etcd <<EOF
#[Member]
ETCD_NAME="etcd01"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.0.205:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.0.205:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.0.205:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.0.205:2379"
ETCD_INITIAL_CLUSTER="etcd01=https://192.168.0.205:2380,etcd02=https://192.168.0.206:2380,etcd03=https://192.168.0.207:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF

备注

ETCD_NAME                           # 节点名称
ETCD_DATA_DIR                       # 数据目录
ETCD_LISTEN_PEER_URLS               # 集群通信监听地址
ETCD_LISTEN_CLIENT_URLS             # 客户端访问监听地址
ETCD_INITIAL_ADVERTISE_PEER_URLS    # 集群通告地址
ETCD_ADVERTISE_CLIENT_URLS          # 客户端通告地址
ETCD_INITIAL_CLUSTER                # 集群节点地址
ETCD_INITIAL_CLUSTER_TOKEN          # 集群 Token
ETCD_INITIAL_CLUSTER_STATE          # 加入集群的当前状态，new 是新集群，existing 表示加入已有

systemd管理etcd：

cat > /usr/lib/systemd/system/etcd.service <<-'EOF'
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
EnvironmentFile=/opt/etcd/cfg/etcd

ExecStart=/opt/etcd/bin/etcd \
--name=${ETCD_NAME} \
--data-dir=${ETCD_DATA_DIR} \
--listen-peer-urls=${ETCD_LISTEN_PEER_URLS} \
--listen-client-urls=${ETCD_LISTEN_CLIENT_URLS},http://127.0.0.1:2379 \
--advertise-client-urls=${ETCD_ADVERTISE_CLIENT_URLS} \
--initial-advertise-peer-urls=${ETCD_INITIAL_ADVERTISE_PEER_URLS} \
--initial-cluster=${ETCD_INITIAL_CLUSTER} \
--initial-cluster-token=${ETCD_INITIAL_CLUSTER_TOKEN} \
--cert-file=/opt/etcd/ssl/server.pem \
--key-file=/opt/etcd/ssl/server-key.pem \
--peer-cert-file=/opt/etcd/ssl/server.pem \
--peer-key-file=/opt/etcd/ssl/server-key.pem \
--trusted-ca-file=/opt/etcd/ssl/ca.pem \
--peer-trusted-ca-file=/opt/etcd/ssl/ca.pem

Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

把刚才生成的证书拷贝到配置文件中的位置：

cd /iba/tools
cp ca*pem server*pem /opt/etcd/ssl/

把二进制文件和配置文件复制到 nodes 节点上

ansible node -m shell -a 'mkdir /opt/etcd/{bin,cfg,ssl} -p'
cd /opt/etcd/bin/
ansible node -m copy -a 'src=etcd dest=/opt/etcd/bin/'
ansible node -m copy -a 'src=etcdctl dest=/opt/etcd/bin/'
ansible node -m shell -a 'chmod +x /opt/etcd/bin/etcd'
ansible node -m shell -a 'chmod +x /opt/etcd/bin/etcdctl'

cd /opt/etcd/ssl/
ansible node -m copy -a 'src=ca-key.pem dest=/opt/etcd/ssl/'
ansible node -m copy -a 'src=ca.pem dest=/opt/etcd/ssl/'
ansible node -m copy -a 'src=server-key.pem dest=/opt/etcd/ssl/'
ansible node -m copy -a 'src=server.pem dest=/opt/etcd/ssl/'
ansible node -m shell -a 'ls /opt/etcd/ssl/'

ansible node -m copy -a 'src=/opt/etcd/cfg/etcd dest=/opt/etcd/cfg/'
ansible node -m copy -a 'src=/usr/lib/systemd/system/etcd.service dest=/usr/lib/systemd/system/'

修改 node1，node2 上面的 /opt/etcd/cfg/etcd 为对应的值

ETCD_NAME                            # 修改名称
ETCD_LISTEN_PEER_URLS                # 修改IP
ETCD_LISTEN_CLIENT_URLS              # 修改IP
ETCD_INITIAL_ADVERTISE_PEER_URLS     # 修改IP
ETCD_ADVERTISE_CLIENT_URLS           # 修改IP

启动 etcd

ansible node -m shell -a 'systemctl enable etcd'
ansible node -m shell -a 'systemctl start etcd '

检查etcd集群状态

cd /opt/etcd/ssl

/opt/etcd/bin/etcdctl \
--ca-file=ca.pem --cert-file=server.pem --key-file=server-key.pem \
--endpoints="https://192.168.0.205:2379,https://192.168.0.206:2379,https://192.168.0.207:2379" \
cluster-health