K8S 高可用外部 etcd运行时 (一) 安装 etcd 集群

K8S 1.20.5 高可用外部 etcd , Docker 容器运行时 (一) 安装 etcd 集群

 

架构

文中使用到的服务器ip及角色对应如下：

IP	角色	其他软件
172.16.16.180	k8s-master-01	etcd
172.16.16.181	k8s-master-02	etcd
172.16.16.182	k8s-master-03	etcd
172.16.16.190	k8s-node-01
172.16.16.188	VIP	nginx

生成 etcd 证书

在 k8s-master-01 上操作

mkdir -p /data/software/
cd /data/software/

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

# 自签证书颁发机构（CA）
mkdir -p ~/etcd_tls
cd ~/etcd_tls
cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "www": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF


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

# 生成 ca 证书 (ca.pem 和 ca-key.pem 文件)
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

# 使用自签CA签发Etcd HTTPS证书
# 创建证书申请文件：
cat > server-csr.json << EOF
{
    "CN": "etcd",
    "hosts": [
    "172.16.16.180",
    "172.16.16.181",
    "172.16.16.182"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing"
        }
    ]
}
EOF

# 注：上述文件hosts字段中IP为所有etcd节点的集群内部通信IP，一个都不能少！为了方便后期扩容可以多写几个预留的IP。
# 生成证书 (server.pem 和 server-key.pem)：
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server

mkdir /opt/etcd/{bin,cfg,ssl} -p

cp ~/etcd_tls/ca*pem ~/etcd_tls/server*pem /opt/etcd/ssl/

安装 etcd

在 k8s-master-01 上操作

cd /data/software/

# 下载，可能会出现网络不通的情况
wget https://github.com/etcd-io/etcd/releases/download/v3.4.14/etcd-v3.4.14-linux-amd64.tar.gz

tar zxvf etcd-v3.4.14-linux-amd64.tar.gz 

mv etcd-v3.4.14-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

cat > /opt/etcd/cfg/etcd.conf << EOFETCD_NAME="etcd-1"
#[Member]
ETCD_NAME="etcd-1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://172.16.16.180:2380"
ETCD_LISTEN_CLIENT_URLS="https://172.16.16.180:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://172.16.16.180:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://172.16.16.180:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://172.16.16.180:2380,etcd-2=https://172.16.16.181:2380,etcd-3=https://172.16.16.182:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF

# 参数说明
ETCD_NAME : 节点名称，集群中唯一
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表示加入已有集群

# 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.conf
ExecStart=/opt/etcd/bin/etcd --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 --logger=zap
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

# 把配置拷贝到其他 etcd 节点
scp -r /opt/etcd/ root@172.16.16.181:/opt/
scp /usr/lib/systemd/system/etcd.service root@172.16.16.181:/usr/lib/systemd/system/
scp -r /opt/etcd/ root@172.16.16.182:/opt/
scp /usr/lib/systemd/system/etcd.service root@172.16.16.182:/usr/lib/systemd/system/

# 启动 etcd 
systemctl daemon-reload
systemctl start etcd
systemctl enable etcd

其他两个 etcd 节点安装

在 k8s-master-02 和 k8s-master-03 上操作

vi /opt/etcd/cfg/etcd.conf
#[Member]
ETCD_NAME="etcd-1" # 修改此处，节点2改为etcd-2，节点3改为etcd-3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://172.16.16.180:2380"   # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://172.16.16.180:2379" # 修改此处为当前服务器IP

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://172.16.16.180:2380" # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://172.16.16.180:2379"       # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://172.16.16.180:2380,etcd-2=https://172.16.16.181:2380,etcd-3=https://172.16.16.182:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

# 启动 etcd 
systemctl daemon-reload
systemctl start etcd
systemctl enable etcd

检查

在 k8s-master-01 上操作

ETCDCTL_API=3 /opt/etcd/bin/etcdctl \
--cacert=/opt/etcd/ssl/ca.pem \
--cert=/opt/etcd/ssl/server.pem \
--key=/opt/etcd/ssl/server-key.pem \
--endpoints=172.16.16.180:2379,172.16.16.181:2379,172.16.16.182:2379 \
endpoint health --write-out=table

+--------------------+--------+-------------+-------+
|      ENDPOINT      | HEALTH |    TOOK     | ERROR |
+--------------------+--------+-------------+-------+
| 172.16.16.180:2379 |   true | 18.057212ms |       |
| 172.16.16.181:2379 |   true | 18.966895ms |       |
| 172.16.16.182:2379 |   true | 20.987225ms |       |
+--------------------+--------+-------------+-------+