k8s1.13.0二进制部署-ETCD集群（一）

Kubernetes集群中主要存在两种类型的节点：master、minion节点。

Minion节点为运行 Docker容器的节点，负责和节点上运行的 Docker 进行交互，并且提供了代理功能。
Master节点负责对外提供一系列管理集群的API接口，并且通过和 Minion 节点交互来实现对集群的操作管理。

kubernetes必备组件

kube-apiserver：集群的统一入口，各组件协调者，以RESTful API提供接口服务，所有对象资源的增删改查和监听操作都交给APIServer处理后再提交给Etcd存储。
kube-controller-manager：处理集群中常规后台任务，一个资源对应一个控制器，而ControllerManager就是负责管理这些控制器的。
kube-scheduler：根据调度算法为新创建的Pod选择一个Node节点，可以任意部署,可以部署在同一个节点上,也可以部署在不同的节点上。
etcd：分布式键值存储系统。用于保存集群状态数据，比如Pod、Service等对象信息。
kubelet：Master在Node节点上的Agent，管理本机运行容器的生命周期，比如创建容器、Pod挂载数据卷、下载secret、获取容器和节点状态等工作。kubelet将每个Pod转换成一组容器。
kube-proxy：在Node节点上实现Pod网络代理，维护网络规则和四层负载均衡工作。
docker或rocket：容器引擎，运行容器。
Pod网络：Pod要能够相互间通信，K8S集群必须部署Pod网络，flannel是其中一种的可选方案，是CoreOS 团队针对 Kubernetes 设计的一个覆盖网络（Overlay Network）工具。

kubernetes集群架构与组建：

准备部署环境：

vip            192.168.0.130    keepalived
k8s-master1    192.168.0.123    kube-apiserver,kube-controller-manager,kube-scheduler,etcd
k8s-master2    192.168.0.124    kube-apiserver,kube-controller-manager,kube-scheduler
k8s-node01     192.168.0.125    kubelet,kube-proxy,docker,flannel,etcd
k8s-node02     192.168.0.126    kubelet,kube-proxy,docker,flannel,etcd

系统环境初始化：

#系统更新
yum install -y epel-release; yum update -y

#修改个节点主机名
hostnamectl set-hostname k8s-master1
hostnamectl set-hostname k8s-master2
hostnamectl set-hostname k8s-node1
hostnamectl set-hostname k8s-node2

#master1 IP
[root@k8s-master1 ~]# ifconfig ens32
ens32: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.0.123  netmask 255.255.255.0  broadcast 192.168.0.255
        inet6 fe80::20c:29ff:fe8a:2b5f  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:8a:2b:5f  txqueuelen 1000  (Ethernet)
        RX packets 821  bytes 84238 (82.2 KiB)
        RX errors 0  dropped 2  overruns 0  frame 0
        TX packets 143  bytes 18221 (17.7 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
#master2 IP
[root@k8s-master2 ~]# ifconfig ens32
ens32: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.0.124  netmask 255.255.255.0  broadcast 192.168.0.255
        inet6 fe80::20c:29ff:fe77:dc9c  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:77:dc:9c  txqueuelen 1000  (Ethernet)
        RX packets 815  bytes 81627 (79.7 KiB)
        RX errors 0  dropped 2  overruns 0  frame 0
        TX packets 158  bytes 20558 (20.0 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
#node01 IP
[root@k8s-node01 ~]# ifconfig ens32
ens32: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.0.125  netmask 255.255.255.0  broadcast 192.168.0.255
        inet6 fe80::20c:29ff:fe80:7949  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:80:79:49  txqueuelen 1000  (Ethernet)
        RX packets 830  bytes 85270 (83.2 KiB)
        RX errors 0  dropped 2  overruns 0  frame 0
        TX packets 152  bytes 19376 (18.9 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
#node02 IP
[root@k8s-node02 ~]# ifconfig ens32
ens32: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.0.126  netmask 255.255.255.0  broadcast 192.168.0.255
        inet6 fe80::20c:29ff:fe7a:e67b  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:7a:e6:7b  txqueuelen 1000  (Ethernet)
        RX packets 867  bytes 87775 (85.7 KiB)
        RX errors 0  dropped 2  overruns 0  frame 0
        TX packets 157  bytes 19866 (19.4 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

#同步时间
yum -y install ntp
systemctl start ntpd
ntpdate  cn.pool.ntp.org

#关闭selinux
setenforce  0
sed -i "s/^SELINUX=enforcing/SELINUX=disabled/g" /etc/sysconfig/selinux
sed -i "s/^SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config
sed -i "s/^SELINUX=permissive/SELINUX=disabled/g" /etc/sysconfig/selinux
sed -i "s/^SELINUX=permissive/SELINUX=disabled/g" /etc/selinux/config
getenforce

#关闭swap
swapoff -a
sed -i 's/.*swap.*/#&/' /etc/fstab
cat /etc/fstab

#设置内核
cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf

#准备部署目录
mkdir -p /opt/kubernetes/{bin,cfg,ssl,log}
echo 'export PATH=/opt/kubernetes/bin:$PATH' > /etc/profile.d/k8s.sh
source /etc/profile.d/k8s.sh

CA证书创建和分发：

从k8s的1.8版本开始，K8S系统各组件需要使用TLS证书对通信进行加密。每一个K8S集群都需要独立的CA证书体系。CA证书有以下三种：easyrsa、openssl、cfssl。这里使用cfssl证书，也是目前使用最多的，相对来说配置简单一些，通过json的格式，把证书相关的东西配置进去即可。这里使用cfssl的版本为1.2版本。

1、安装CFSSL

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

2、初始化cfssl

mkdir ssl && cd ssl
cfssl print-defaults config > config.json
cfssl print-defaults csr > csr.json

3、创建用来生成CA文件的json配置文件

[root@k8s-master1 ssl]# vim ca-config.json
{
  "signing": {
    "default": {
      "expiry": "8760h"
    },
    "profiles": {
      "kubernetes": {
        "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ],
        "expiry": "8760h"
      }
    }
  }
}

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;

4、创建用来生成CA证书签名请求的json配置文件

[root@k8s-master1 ssl]# vim ca-csr.json
{
  "CN": "kubernetes",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ]
}

“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)；

5、生成CA证书（ca.pem）和密钥（ca-key.pem）

[root@k8s-master1 ssl]# cfssl gencert -initca ca-csr.json | cfssljson -bare ca
2018/12/14 13:36:34 [INFO] generating a new CA key and certificate from CSR
2018/12/14 13:36:34 [INFO] generate received request
2018/12/14 13:36:34 [INFO] received CSR
2018/12/14 13:36:34 [INFO] generating key: rsa-2048
2018/12/14 13:36:34 [INFO] encoded CSR
2018/12/14 13:36:34 [INFO] signed certificate with serial number 685737089592185658867716737752849077098687904892

将证书和密钥分发到其他节点

cp ca.csr ca.pem ca-key.pem ca-config.json /opt/kubernetes/ssl
scp ca.csr ca.pem ca-key.pem ca-config.json 192.168.0.125:/opt/kubernetes/ssl
scp ca.csr ca.pem ca-key.pem ca-config.json 192.168.0.126:/opt/kubernetes/ssl

ETCD部署

所有持久化的状态信息以KV的形式存储在ETCD中。类似zookeeper，提供分布式协调服务。之所以说kubenetes各个组件是无状态的，就是因为其中把数据都存放在ETCD中。由于ETCD支持集群，这里在三台主机上都部署上ETCD。

创建etcd证书签名请求

[root@k8s-master1 ssl]# vim etcd-csr.json
{
  "CN": "etcd",
  "hosts": [
    "127.0.0.1",
    "192.168.0.123",
    "192.168.0.125",
    "192.168.0.126"
  ],
  "key": {
    "algo": "rsa",
    "size":
  },
  "names": [
    {
     "C": "CN",
     "ST": "BeiJing",
     "L": "BeiJing",
     "O": "k8s",
     "OU": "System"
    }
  ]
}

生成etcd证书和私钥

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

将证书复制到其他节点

cp etcd*.pem /opt/kubernetes/ssl/
scp etcd*.pem 192.168.0.125:/opt/kubernetes/ssl/
scp etcd*.pem 192.168.0.126:/opt/kubernetes/ssl/

准备二进制文件

二进制包下载地址：https://github.com/coreos/etcd/releases

cd /usr/local/src/
wget https://github.com/etcd-io/etcd/releases/download/v3.3.10/etcd-v3.3.10-linux-amd64.tar.gz
tar xf etcd-v3.3.10-linux-amd64.tar.gz
cd etcd-v3.3.10-linux-amd64
cp etcd etcdctl /opt/kubernetes/bin/
scp etcd etcdctl 192.168.0.125:/opt/kubernetes/bin/
scp etcd etcdctl 192.168.0.126:/opt/kubernetes/bin/

设置etcd配置文件

[root@k8s-master1 ~]# vim /opt/kubernetes/cfg/etcd.conf

#[member]
ETCD_NAME="etcd-node1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.0.123:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.0.123:2379,https://127.0.0.1:2379"
#[cluster]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.0.123:2380"
ETCD_INITIAL_CLUSTER="etcd-node1=https://192.168.0.123:2380,etcd-node2=https://192.168.0.125:2380,etcd-node3=https://192.168.0.126:2380"
ETCD_INITIAL_CLUSTER_STATE="new"
ETCD_INITIAL_CLUSTER_TOKEN="k8s-etcd-cluster"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.0.123:2379"
#[security]
CLIENT_CERT_AUTH="true"
ETCD_CA_FILE="/opt/kubernetes/ssl/ca.pem"
ETCD_CERT_FILE="/opt/kubernetes/ssl/etcd.pem"
ETCD_KEY_FILE="/opt/kubernetes/ssl/etcd-key.pem"
PEER_CLIENT_CERT_AUTH="true"
ETCD_PEER_CA_FILE="/opt/kubernetes/ssl/ca.pem"
ETCD_PEER_CERT_FILE="/opt/kubernetes/ssl/etcd.pem"
ETCD_PEER_KEY_FILE="/opt/kubernetes/ssl/etcd-key.pem"

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表示加入已有集群

创建etcd系统服务

[root@k8s-master1 ~]# vim /usr/lib/systemd/system/etcd.service

[Unit]
Description=Etcd Server
After=network.target

[Service]
Type=simple
WorkingDirectory=/var/lib/etcd
EnvironmentFile=-/opt/kubernetes/cfg/etcd.conf
# set GOMAXPROCS to number of processors
ExecStart=/bin/bash -c "GOMAXPROCS=$(nproc) /opt/kubernetes/bin/etcd"
Type=notify

[Install]
WantedBy=multi-user.target

将配置文件和服务文件拷贝到其他两个节点 （记得修改对应的IP和ETCD_NAME）

scp /opt/kubernetes/cfg/etcd.conf 192.168.0.125:/opt/kubernetes/cfg
scp /opt/kubernetes/cfg/etcd.conf 192.168.0.126:/opt/kubernetes/cfg
scp /usr/lib/systemd/system/etcd.service 192.168.0.125:/usr/lib/systemd/system/
scp /usr/lib/systemd/system/etcd.service 192.168.0.126:/usr/lib/systemd/system/

创建ETCD工作目录

mkdir /var/lib/etcd

启动ETCD服务

systemctl daemon-reload
systemctl enable etcd
systemctl start etcd
systemctl status etcd

集群验证

etcdctl --endpoints=https://192.168.0.123:2379,https://192.168.0.125:2379,https://192.168.0.126:2379 \
  --ca-file=/opt/kubernetes/ssl/ca.pem \
  --cert-file=/opt/kubernetes/ssl/etcd.pem \
  --key-file=/opt/kubernetes/ssl/etcd-key.pem cluster-health

返回如下信息说明ETCD集群配置正常：

member 3126a455a15179c6 is healthy: got healthy result from https://192.168.0.125:2379
member 40601cc6f27d1bf1 is healthy: got healthy result from https://192.168.0.123:2379
member 431013e88beab64c is healthy: got healthy result from https://192.168.0.126:2379
cluster is healthy