k8s集群搭建之二：etcd集群的搭建

一介绍

　　　　 Etcd是一个高可用的 Key/Value 存储系统，主要用于分享配置和服务发现。

　　　　 简单：支持 curl 方式的用户 API (HTTP+JSON)

　　　　 安全：可选 SSL 客户端证书认证

　　　　 快速：单实例可达每秒 1000 次写操作

　　　　 可靠：使用 Raft 实现分布式

二搭建开始

2.1 yum 安装etcd服务 (三台执行)

yum  -y install etcd

[root@k8s-master ~]# etcd -version
etcd Version: 3.3.11
Git SHA: 2cf9e51
Go Version: go1.10.3
Go OS/Arch: linux/amd64

2.2 安装cfssl工具，并配置证书:这里采用的是共用证书的方式（master执行）

mkdir  /etc/etcd/ssl

cd /etc/etcd/ssl

cat etcd-root-ca-csr.json #etcd根CA证书

{

   "key": {

     "algo": "rsa",

     "size": 4096

   },

   "names": [

     {

       "O": "etcd",

       "OU": "etcd Security",

       "L": "Beijing",

       "ST": "Beijing",

       "C": "CN"

     }

   ],

   "CN": "etcd-root-ca"

}

cat etcd-gencert.json #etcd集群证书

{

  "signing": {

    "default": {

        "usages": [

          "signing",

          "key encipherment",

          "server auth",

          "client auth"

        ],

        "expiry": "87600h"

    }

  }

}

cat etcd-csr.json #etcd集群证书

{

  "key": {

    "algo": "rsa",

    "size": 4096

  },

  "names": [

    {

      "O": "etcd",

      "OU": "etcd Security",

      "L": "Beijing",

      "ST": "Beijing",

      "C": "CN"

    }

  ],

  "CN": "etcd",

  "hosts": [

    "127.0.0.1",

    "localhost",

    "192.168.137.66",

    "192.168.137.16",

    "192.168.137.26",

    "k8s-master",

    "k8s-node1",

    "k8s-node2"            -------->注意最后没有 ，

  ]

}

下载 cfssl

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

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

chmod +x cfssl_linux-amd64 cfssljson_linux-amd64

mv cfssl_linux-amd64 /usr/local/bin/cfssl

mv cfssljson_linux-amd64 /usr/local/bin/cfssljson

生成证书

cfssl gencert --initca=true etcd-root-ca-csr.json | cfssljson --bare etcd-root-ca

cfssl gencert --ca etcd-root-ca.pem --ca-key etcd-root-ca-key.pem --config etcd-gencert.json etcd-csr.json | cfssljson --bare etcd

生成的文件列表如下 tree .

.

├── etcd.csr

├── etcd-csr.json

├── etcd-gencert.json

├── etcd-key.pem

├── etcd.pem

├── etcd-root-ca.csr

├── etcd-root-ca-csr.json

├── etcd-root-ca-key.pem

├── etcd-root-ca.pem

2.3 分发证书(master执行)

I="192.168.137.16 192.168.137.26"

for IP in $I; do

    ssh root@$IP mkdir /etc/etcd/ssl/

    scp *.pem root@$IP:/etc/etcd/ssl/

    ssh root@$IP chown -R etcd:etcd /etc/etcd/ssl/

    ssh root@$IP chmod -R 755 /etc/etcd/

done

#本台服务器也要设置权限
cd  /etc/etcd/ssl
chown -R etcd:etcd /etc/etcd/ssl
chmod -R 755 /etc/etcd/ssl

2.4 修改配置文件(master执行)

[root@k8s-master ssl]# cat /etc/etcd/etcd.conf |grep -v '^#'

ETCD_DATA_DIR="/var/lib/etcd/default.etcd"

ETCD_LISTEN_PEER_URLS="https://192.168.137.66:2380"

ETCD_LISTEN_CLIENT_URLS="https://192.168.137.66:2379,http://127.0.0.1:2379"

ETCD_NAME="etcd01"

ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.137.66:2380"

ETCD_ADVERTISE_CLIENT_URLS="https://192.168.137.66:2379"

ETCD_INITIAL_CLUSTER="etcd01=https://192.168.137.66:2380,etcd02=https://192.168.137.16:2380,etcd03=https://192.168.137.26:2380"

ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"

ETCD_INITIAL_CLUSTER_STATE="new"    #注意状态为new

ETCD_CERT_FILE="/etc/etcd/ssl/etcd.pem"

ETCD_KEY_FILE="/etc/etcd/ssl/etcd-key.pem"

ETCD_CLIENT_CERT_AUTH="True"

ETCD_TRUSTED_CA_FILE="/etc/etcd/ssl/etcd-root-ca.pem"

ETCD_AUTO_TLS="True"

ETCD_PEER_CERT_FILE="/etc/etcd/ssl/etcd.pem"

ETCD_PEER_KEY_FILE="/etc/etcd/ssl/etcd-key.pem"

ETCD_PEER_CLIENT_CERT_AUTH="True"

ETCD_PEER_TRUSTED_CA_FILE="/etc/etcd/ssl/etcd-root-ca.pem"

ETCD_PEER_AUTO_TLS="True"

其他节点：注意上面的蓝色部分是要修改的（其他节点上执行）

# k8s-node1

ETCD_LISTEN_PEER_URLS="https://192.168.137.16:2380"

ETCD_LISTEN_CLIENT_URLS="https://192.168.137.16:2379,http://127.0.0.1:2379"

ETCD_NAME="etcd02"

ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.137.16:2380"

ETCD_ADVERTISE_CLIENT_URLS="https://192.168.137.16:2379"

ETCD_INITIAL_CLUSTER_STATE="existing"  #注意这里，不能为new，有的是exist,但是这个版本测试为existing

# k8s-node2

ETCD_LISTEN_PEER_URLS="https://192.168.137.26:2380"

ETCD_LISTEN_CLIENT_URLS="https://192.168.137.26:2379,http://127.0.0.1:2379"

ETCD_NAME="etcd02"

ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.137.26:2380"

ETCD_ADVERTISE_CLIENT_URLS="https://192.168.137.26:2379"

ETCD_INITIAL_CLUSTER_STATE="existing"

2.5 启动(master先执行，其他两台后执行)：master启动时间漫长，说明配置有问题

systemctl  daemon-reload

systemctl  start etcd

systemctl  enable  etcd

2.6 设置 etcdctl 的版本，有 v2和v3版本，他们的命令不同，这里采用v3版本

#export ETCDCTL_API=3
#cat /etc/profile
 .....
 export ETCDCTL_API=3

2.7 验证节点状态

etcdctl --cacert=/etc/etcd/ssl/etcd-root-ca.pem --cert=/etc/etcd/ssl/etcd.pem --key=/etc/etcd/ssl/etcd-key.pem   \
--endpoints=https://192.168.137.66:2379,https://192.168.137.16:2379,https://192.168.137.26:2379 endpoint health

[root@k8s-master ssl]# etcdctl --cacert=/etc/etcd/ssl/etcd-root-ca.pem --cert=/etc/etcd/ssl/etcd.pem --key=/etc/etcd/ssl/etcd-key.pem --endpoints=https://192.168.137.66:2379,https://192.168.137.16:2379,https://192.168.137.26:2379 endpoint health

https://192.168.137.16:2379 is healthy: successfully committed proposal: took = 4.807966ms

https://192.168.137.66:2379 is healthy: successfully committed proposal: took = 3.790949ms
https://192.168.137.66:2379 is healthy: successfully committed proposal: took = 2.493048ms

2.8 版本为2时对etcd的检查

export ETCDCTL_API=2

[root@k8s-master ssl]# etcdctl --ca-file=/etc/etcd/ssl/etcd-root-ca.pem --cert-file=/etc/etcd/ssl/etcd.pem --key-file=/etc/etcd/ssl/etcd-key.pem  \
  --endpoints=https://192.168.137.66:2379,https://192.168.137.16:2379 cluster-health

member 457528f516aae01a is healthy: got healthy result from https://192.168.137.66:2379

member b13478c4279881c2 is healthy: got healthy result from https://192.168.137.16:2379

cluster is healthy

三报错以及解决

error 1:执行etcdctl命令检查时报错

etcdctl --cacert=/etc/etcd/ssl/etcd-root-ca.pem --cert=/etc/etcd/ssl/etcd.pem --key=/etc/etcd/ssl/etcd-key.pem   \
--endpoints=https://192.168.137.66:2379,https://192.168.137.16:2379,https://192.168.137.26:2379 endpoint health

........
flag provided but not defined: -cacert

solution：版本不同，命令的格式不同

export ETCDCTL_API=3

error 2: failed to check the health of member 6c70a880257288f on https://192.168.137.16:2379: Get https://192.168.137.16:2379/health: remote error: tls: bad certificate

solution:证书问题

重做步骤2.2和2.3

error 3: couldn't find local name "etcd04" in the initial cluster configuration

solution:配置文件问题

检查步骤2.4，着重看以下方面

ETCD_NAME="etcd01"

ETCD_INITIAL_CLUSTER="etcd01=https://192.168.137.66:2380,etcd02=https://192.168.137.16:2380,etcd03=https://192.168.137.26:2380"

接着执行下面的命令

systemctl stop etcd

rm -rf /var/lib/etcd/default.etcd

systemctl daemon-reload && systemctl restart etcd

error 4：错误如下

[root@k8s-node1 ~]# etcdctl member list

Error: dial tcp 127.0.0.1:2379: connect: connection refused

solution:根据步骤2.4修改

ETCD_LISTEN_CLIENT_URLS="https://192.168.137.16:2379,http://127.0.0.1:2379"

[root@k8s-node1 ~]# etcdctl member list
457528f516aae01a, started, etcd01, https://192.168.137.66:2380, https://192.168.137.66:2379
b13478c4279881c2, started, etcd02, https://192.168.137.16:2380, https://192.168.137.16:2379

a93278c4200188c5, started, etcd03, https://192.168.137.26:2380, https://192.168.137.26:2379