etcd 是基于 Raft 的分布式 key-value 存储系统,由 CoreOS 开发,常用于服务发现、共享配置以及并发控制(如 leader 选举、分布式锁等)。kubernetes 使用 etcd 存储所有运行数据。
本文档介绍部署一个三节点高可用 etcd 集群的步骤:
etcd 集群各节点的名称和 IP 如下:
systemctl stop iptables
systemctl stop firewalld
systemctl disable iptables
systemctl disable firewalld
vi /etc/selinux/config
SELINUX=disable
vim /etc/hosts
192.168.110.100 k8s-master
192,168.110.101 k8s-node01
192.168.110.102 k8s-node02
useradd etcd -d /data/home -c "Etcd user" -r -s /sbin/nologin
在每个节点下载etcd二进制文件
wget https://github.com/coreos/etcd/releases/download/v3.3.7/etcd-v3.3.7-linux-amd64.tar.gz
tar -xvf etcd-v3.3.7-linux-amd64.tar.gz
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
mkdir /opt/ssl
cd /opt/ssl
cfssl print-defaults config > config.json
cfssl print-defaults csr > csr.json
然后分别修改这两个文件为如下内容
config.json
cat > config.json <<EOF
{
"signing": {
"default": {
"expiry": "87600h"
},
"profiles": {
"kubernetes": {
"usages": [
"signing",
"key encipherment",
"server auth",
"client auth"
],
"expiry": "87600h"
}
}
}
}
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;
csr.json
cat > csr.json <<EOF
{
"CN": "kubernetes",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "System"
}
]
}
EOF
CN:
Common Name,kube-apiserver 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;
O:
Organization,kube-apiserver 从证书中提取该字段作为请求用户所属的组(Group);
生成 CA 证书和私钥
cd /opt/ssl
cfssl gencert -initca csr.json | cfssljson -bare ca
CA 有关证书列表如下:
[root@k8s-master ssl]# tree
.
├── ca.csr
├── ca-key.pem
├── ca.pem
├── config.json
└── csr.json
在 /opt/ssl
下添加文件 etcd-csr.json
,内容如下
{
"CN": "etcd",
"hosts": [
"127.0.0.1",
"192.168.110.100",
"192.168.110.101",
"192.168.110.102"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "etcd",
"OU": "Etcd Security"
}
]
}
生成 etcd 证书和密钥
cd /opt/ssl
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
etcd 有关证书证书列表如下
ls etcd*
etcd.csr etcd-csr.json etcd-key.pem etcd.pem
将证书分别传到各个节点并设置权限
chmod 644 /opt/ssl/*
tar -xvf etcd-v3.3.4-linux-amd64.tar.gz
cd etcd-v3.3.4-linux-amd64
cp mv etcd* /opt/platform/etcd/
vim /opt/platform/etcd/etcd.conf
# [member]
ETCD_NAME="etcd1" #不同机器需要做修改 与下面集群配置相对应
ETCD_DATA_DIR="/data/etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.110.100:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.110.100:2379,http://127.0.0.1:2379"
# [cluster]
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.110.100:2379"
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.110.100:2380"
ETCD_INITIAL_CLUSTER="etcd1=https://192.168.110.100:2380,etcd2=https://192.168.110.101:2380,etcd3=https://192.168.110.102:2380"
ETCD_INITIAL_CLUSTER_STATE=new
ETCD_INITIAL_CLUSTER_TOKEN=etcd-cluster
ETCD_ENABLE_V2="true"
配置说明
ETCD_NAME:
etcd 集群中的节点名,这里可以随意,可区分且不重复就行。
ETCD_LISTEN_PEER_URLS:
监听的用于节点之间通信的 URL,可监听多个,集群内部将通过这些 URL 进行数据交互(如选举、数据同步等)。
ETCD_LISTEN_CLIENT_URLS:
监听的用于客户端通信的 URL,同样可以监听多个。
ETCD_ADVERTISE_CLIENT_URLS:
建议使用的客户端通信 URL,该值用于 etcd 代理或 etcd 成员与 etcd 节点通信。
ETCD_INITIAL_ADVERTISE_PEER_URLS:
建议用于节点之间通信的 URL,节点间将以该值进行通信。
ETCD_INITIAL_CLUSTER:
也就是集群中所有的 initial--advertise-peer-urls 的合集。
ETCD_INITIAL_CLUSTER_STATE:
新建集群的标志。
ETCD_INITIAL_CLUSTER_TOKEN:
节点的 token 值,设置该值后集群将生成唯一 ID,并为每个节点也生成唯一 ID,当使用相同配置文件再启动一个集群时,只要该 token 值不一样,etcd 集群就不会相互影响。
flannel操作etcd使用的是v2的API,而kubernetes操作etcd使用的v3的API,为了兼容flannel,将默认开启v2版本,故配置文件中设置 ETCD_ENABLE_V2="true"
vim /usr/lib/systemd/system/etcd.service
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target
[Service]
Type=notify
EnvironmentFile=/opt/platform/etcd/etcd.conf
ExecStart=/usr/bin/etcd \
--cert-file=/opt/ssl/etcd.pem \
--key-file=/opt/ssl/etcd-key.pem \
--peer-cert-file=/opt/ssl/etcd.pem \
--peer-key-file=/opt/ssl/etcd-key.pem \
--trusted-ca-file=/opt/ssl/ca.pem \
--peer-trusted-ca-file=/opt/ssl/ca.pem
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
mkdir -p /opt/platform/etcd/data && chown etcd:etcd -R /opt/platform/etcd && chmod 755 /opt/platform/etcd/data
systemctl enable etcd.service && systemctl start etcd.service
ETCD3.4版本ETCDCTL_API=3 etcdctl 和 etcd --enable-v2=false 成为了默认配置,如要使用v2版本,执行etcdctl时候需要设置ETCDCTL_API环境变量,例如:ETCDCTL_API=2 etcdctl
ETCD3.4版本会自动读取环境变量的参数,所以EnvironmentFile文件中有的参数,不需要再次在ExecStart启动参数中添加,二选一,如同时配置,会触发以下类似报错“etcd: conflicting environment variable "ETCD_NAME" is shadowed by corresponding command-line flag (either unset environment variable or disable flag)”
flannel操作etcd使用的是v2的API,而kubernetes操作etcd使用的v3的API
[root@localhost data]# etcdctl --endpoints=https://192.168.110.100:2379 --cacert="/opt/ssl/ca.pem" --cert="/opt/ssl/etcd.pem" --key="/opt/ssl/etcd-key.pem" endpoint health
https://192.168.110.100:2379 is healthy: successfully committed proposal: took = 16.533873ms
[root@localhost data]# etcdctl --endpoints=https://192.168.110.101:2379 --cacert="/opt/ssl/ca.pem" --cert="/opt/ssl/etcd.pem" --key="/opt/ssl/etcd-key.pem" endpoint health
https://192.168.110.101:2379 is healthy: successfully committed proposal: took = 24.19221ms
[root@localhost data]# etcdctl --endpoints=https://192.168.110.102:2379 --cacert="/opt/ssl/ca.pem" --cert="/opt/ssl/etcd.pem" --key="/opt/ssl/etcd-key.pem" endpoint health
https://192.168.110.102:2379 is healthy: successfully committed proposal: took = 20.12311ms
查看 etcd 集群成员
etcdctl --endpoints=https://192.168.110.100:2379 --cacert="/opt/ssl/ca.pem" --cert="/opt/ssl/etcd.pem" --key="/opt/ssl/etcd-key.pem" member list
3e49d4614347212d, started, etcd1, https://192.168.110.100:2380, https://192.168.110.100:2379, false
8d2730b8d7d6bbb3, started, etcd3, https://192.168.110.102:2380, https://192.168.110.102:2379, false
f7edfa2ae51ff5e8, started, etcd2, https://192.168.110.101:2380, https://192.168.110.101:2379, false
原文:https://www.cnblogs.com/xiexun/p/14620133.html