K8S入门系列之集群二进制部署--> master篇(二)

组件版本和配置策略

组件版本

  • Kubernetes 1.16.2
  • Docker 19.03-ce
  • Etcd 3.3.17 https://github.com/etcd-io/etcd/releases/
  • Flanneld 0.11.0 https://github.com/coreos/flannel/releases/

  • 插件:

  • 镜像仓库:
    docker registry
    harbor

主要配置策略

  • kube-apiserver:
    使用 keepalived 和 haproxy 实现 3 节点高可用;
    关闭非安全端口 8080 和匿名访问;
    在安全端口 6443 接收 https 请求;
    严格的认证和授权策略 (x509、token、RBAC);
    开启 bootstrap token 认证,支持 kubelet TLS bootstrapping;
    使用 https 访问 kubelet、etcd,加密通信;

  • kube-controller-manager:
    3 节点高可用;主备备
    关闭非安全端口,在安全端口 10252 接收 https 请求;
    使用 kubeconfig 访问 apiserver 的安全端口;
    自动 approve kubelet 证书签名请求 (CSR),证书过期后自动轮转;
    各 controller 使用自己的 ServiceAccount 访问 apiserver;

  • kube-scheduler:
    3 节点高可用;主备备
    使用 kubeconfig 访问 apiserver 的安全端口;

  • kubelet:
    使用 kubeadm 动态创建 bootstrap token,也可以在 apiserver 中静态配置;
    使用 TLS bootstrap 机制自动生成 client 和 server 证书,过期后自动轮转;
    在 KubeletConfiguration 类型的 JSON 文件配置主要参数;
    关闭只读端口,在安全端口 10250 接收 https 请求,对请求进行认证和授权,拒绝匿名访问和非授权访问;
    使用 kubeconfig 访问 apiserver 的安全端口;

  • kube-proxy:
    使用 kubeconfig 访问 apiserver 的安全端口;
    在 KubeProxyConfiguration 类型的 JSON 文件配置主要参数;
    使用 ipvs 代理模式;

  • 集群插件:

1. 系统初始化

1.01 系统环境&&基本环境配置

[root@localhost ~]# uname -a
Linux localhost.localdomain 4.18.0-80.11.2.el8_0.x86_64 #1 SMP Tue Sep 24 11:32:19 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
[root@localhost ~]# cat /etc/redhat-release 
CentOS Linux release 8.0.1905 (Core) 

1.02 修改各个节点的对应hostname, 并分别写入/etc/hosts

hostnamectl set-hostname k8s-master01
...
# 写入hosts--> 注意是 >> 表示不改变原有内容追加!
cat>> /etc/hosts <<EOF

192.168.2.201 k8s-master01
192.168.2.202 k8s-master02
192.168.2.203 k8s-master03
192.168.2.11 k8s-node01
192.168.2.12 k8s-node02
EOF

1.03 安装依赖包和常用工具

yum install wget vim yum-utils net-tools tar chrony curl jq ipvsadm ipset conntrack iptables sysstat libseccomp -y

1.04 所有节点关闭firewalld, dnsmasq, selinux以及swap

# 关闭防火墙并清空防火墙规则
systemctl disable firewalld && systemctl stop firewalld && systemctl status firewalld
iptables -F && iptables -X && iptables -F -t nat && iptables -X -t nat
iptables -P FORWARD ACCEP

# 关闭dnsmasq否则可能导致docker容器无法解析域名!(centos8不存在!)
systemctl disable --now dnsmasq 

# 关闭selinux  --->selinux=disabled 需重启生效!
setenforce 0 && sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config

# 关闭swap --->注释掉swap那一行, 需重启生效!
swapoff -a && sed -i '/ swap / s/^\(.*\)$/# \1/g' /etc/fstab

1.05 所有节点设置时间同步

timedatectl set-timezone Asia/Shanghai
timedatectl set-local-rtc 0

yum install chrony -y
systemctl enable chronyd && systemctl start chronyd && systemctl status chronyd

1.06 调整内核参数, k8s必备参数!

# 先加载模块
modprobe br_netfilter
cat> kubernetes.conf <<EOF
net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-ip6tables=1
net.ipv6.conf.all.disable_ipv6=1
net.netfilter.nf_conntrack_max = 6553500
net.nf_conntrack_max = 6553500
net.ipv4.tcp_max_tw_buckets = 4096
EOF
  • net.bridge.bridge-nf-call-iptables=1 二层的网桥在转发包时也会被iptables的FORWARD规则所过滤
  • net.ipv6.conf.all.disable_ipv6=1 禁用整个系统所有的ipv6接口, 预防触发docker的bug
  • net.netfilter.nf_conntrack_max 这个默认值是65535,当服务器上的连接超过这个数的时候,系统会将数据包丢掉,直到小于这个值或达到过期时间net.netfilter.nf_conntrack_tcp_timeout_established,默认值432000,5天。期间的数据包都会丢掉。
  • net.ipv4.tcp_max_tw_buckets 这个默认值18000,服务器TIME-WAIT状态套接字的数量限制,如果超过这个数量, 新来的TIME-WAIT套接字会直接释放。过多的TIME-WAIT影响服务器性能,根据服务自行设置.
cp kubernetes.conf  /etc/sysctl.d/kubernetes.conf
sysctl -p /etc/sysctl.d/kubernetes.conf

1.07 所有节点创建k8s工作目录并设置环境变量!

# 在每台机器上创建目录:
mkdir -p /opt/k8s/{bin,cert,script,kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy}
mkdir -p /opt/etcd/{bin,cert}
mkdir -p /opt/lib/etcd
mkdir -p /opt/flanneld/{bin,cert}
mkdir -p /root/.kube
mkdir -p /var/log/kubernetes

# 在每台机器上添加环境变量:
sh -c "echo 'PATH=/opt/k8s/bin:/opt/etcd/bin:/opt/flanneld/bin:$PATH:$HOME/bin:$JAVA_HOME/bin' >> /etc/profile.d/k8s.sh"

source /etc/profile.d/k8s.sh

1.08 无密码 ssh 登录其它节点(为了部署方便!!!)

生成秘钥对

[root@k8s-master01 ~]# ssh-keygen

将自己的公钥发给其他服务器

[root@k8s-master01 ~]# ssh-copy-id root@k8s-master01
[root@k8s-master01 ~]# ssh-copy-id root@k8s-master02
[root@k8s-master01 ~]# ssh-copy-id root@k8s-master03

2. 创建CA根证书和密钥

  • 为确保安全, kubernetes 系统各组件需要使用 x509 证书对通信进行加密和认证。
  • CA (Certificate Authority) 是自签名的根证书,用来签名后续创建的其它证书。

2.01 安装cfssl工具集

[root@k8s-master01 ~]# wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
[root@k8s-master01 ~]# mv cfssl_linux-amd64 /opt/k8s/bin/cfssl

[root@k8s-master01 ~]# wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
[root@k8s-master01 ~]# mv cfssljson_linux-amd64 /opt/k8s/bin/cfssljson

[root@k8s-master01 ~]# wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
[root@k8s-master01 ~]# mv cfssl-certinfo_linux-amd64 /opt/k8s/bin/cfssl-certinfo

chmod +x /opt/k8s/bin/*

2.02 创建根证书CA

  • CA 证书是集群所有节点共享的,只需要创建一个CA证书,后续创建的所有证书都由它签名。

2.02.01 创建配置文件

  • CA 配置文件用于配置根证书的使用场景 (profile) 和具体参数 (usage,过期时间、服务端认证、客户端认证、加密等),后续在签名其它证书时需要指定特定场景。
[root@k8s-master01 ~]# cd /opt/k8s/cert/
[root@k8s-master01 cert]# cat> ca-config.json <<EOF
{
    "signing": {
        "default": {
            "expiry": "876000h"
        },
        "profiles": {
            "kubernetes": {
                "usages": [
                    "signing",
                    "key encipherment",
                    "server auth",
                    "client auth"
                ],
                "expiry": "876000h"
            }
        }
    }
}
EOF
  • 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 可以用该该证书对 server 提供的证书进行验证;
  • client auth :表示 server 可以用该该证书对 client 提供的证书进行验证;

2.02.02 创建证书签名请求文件

[root@k8s-master01 cert]# cat > ca-csr.json <<EOF
{
    "CN": "kubernetes",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "ST": "BeiJing",
            "L": "BeiJing",
            "O": "k8s",
            "OU": "steams"
        }
    ]
}
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);
  • kube-apiserver 将提取的 User、Group 作为 RBAC 授权的用户标识;

2.02.03 生成CA证书和密钥

[root@k8s-master01 cert]# cfssl gencert -initca ca-csr.json | cfssljson -bare ca

# 查看是否生成!
[root@k8s-master01 cert]# ls
ca-config.json  ca.csr  ca-csr.json  ca-key.pem  ca.pem

2.02.04 分发证书文件

  • 简单脚本, 注意传参! 后期想写整合脚本的话可以拿来用!
  • 将生成的 CA 证书、秘钥文件、配置文件拷贝到所有节点的/opt/k8s/cert 目录下:
[root@k8s-master01 cert]# vi /opt/k8s/script/scp_k8s_cacert.sh 

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
    echo ">>> ${master_ip}"
    scp /opt/k8s/cert/ca*.pem /opt/k8s/cert/ca-config.json root@${master_ip}:/opt/k8s/cert
done
[root@k8s-master01 cert]# bash /opt/k8s/script/scp_k8s_cacert.sh 192.168.2.201 192.168.2.202 192.168.2.203

3. 部署etcd集群

  • 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。所以部署三节点高可用!

3.01 下载二进制文件

[root@k8s-master01 ~]# wget https://github.com/etcd-io/etcd/releases/download/v3.3.17/etcd-v3.3.17-linux-amd64.tar.gz
[root@k8s-master01 ~]# tar -xvf etcd-v3.3.17-linux-amd64.tar.gz 

3.02 创建etcd证书和密钥

  • etcd集群要与k8s-->apiserver通信, 所以需要用证书签名验证!

3.02.01 创建证书签名请求

[root@k8s-master01 cert]# cat > /opt/etcd/cert/etcd-csr.json <<EOF
{
    "CN": "etcd",
    "hosts": [
        "127.0.0.1",
        "192.168.2.201",
        "192.168.2.202",
        "192.168.2.203"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "ST": "BeiJing",
            "L": "BeiJing",
            "O": "k8s",
            "OU": "steams"
        }
    ]
}
EOF
  • hosts 字段指定授权使用该证书的 etcd 节点 IP 或域名列表,这里将 etcd 集群的三个节点 IP 都列在其中

3.02.02 生成证书和私钥

[root@k8s-master01 ~]# cfssl gencert -ca=/opt/k8s/cert/ca.pem -ca-key=/opt/k8s/cert/ca-key.pem -config=/opt/k8s/cert/ca-config.json -profile=kubernetes /opt/etcd/cert/etcd-csr.json | cfssljson -bare /opt/etcd/cert/etcd

# 查看是否生成!
[root@k8s-master01 ~]# ls /opt/etcd/cert/*
etcd.csr       etcd-csr.json  etcd-key.pem   etcd.pem  

3.02.03 分发生成的证书, 私钥和etcd安装文件到各etcd节点

[root@k8s-master01 ~]# vi /opt/k8s/script/scp_etcd.sh

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
        echo ">>> ${master_ip}"
        scp /root/etcd-v3.3.17-linux-amd64/etcd* root@${master_ip}:/opt/etcd/bin
        ssh root@${master_ip} "chmod +x /opt/etcd/bin/*"
        scp /opt/etcd/cert/etcd*.pem root@${master_ip}:/opt/etcd/cert/
done
[root@k8s-master01 ~]# bash /opt/k8s/script/scp_etcd.sh 192.168.2.201 192.168.2.202 192.168.2.203

3.03 创建etcd的systemd unit模板及etcd配置文件

创建etcd的systemd unit模板

[root@k8s-master01 ~]# vi /opt/etcd/etcd.service.template

[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target
Documentation=https://github.com/coreos

[Service]
User=root
Type=notify
WorkingDirectory=/opt/lib/etcd/
ExecStart=/opt/etcd/bin/etcd \
    --data-dir=/opt/lib/etcd \
    --name ##ETCD_NAME## \
    --cert-file=/opt/etcd/cert/etcd.pem \
    --key-file=/opt/etcd/cert/etcd-key.pem \
    --trusted-ca-file=/opt/k8s/cert/ca.pem \
    --peer-cert-file=/opt/etcd/cert/etcd.pem \
    --peer-key-file=/opt/etcd/cert/etcd-key.pem \
    --peer-trusted-ca-file=/opt/k8s/cert/ca.pem \
    --peer-client-cert-auth \
    --client-cert-auth \
    --listen-peer-urls=https://##MASTER_IP##:2380 \
    --initial-advertise-peer-urls=https://##MASTER_IP##:2380 \
    --listen-client-urls=https://##MASTER_IP##:2379,http://127.0.0.1:2379 \
    --advertise-client-urls=https://##MASTER_IP##:2379 \
    --initial-cluster-token=etcd-cluster-0    \
    --initial-cluster=etcd0=https://192.168.2.201:2380,etcd1=https://192.168.2.202:2380,etcd2=https://192.168.2.203:2380 \
    --initial-cluster-state=new    
Restart=on-failure
RestartSec=5
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
  • 本示例用脚本替换变量-->##ETCD_NAME##, ##MASTER_IP##
  • WorkingDirectory 、 --data-dir:指定工作目录和数据目录为/opt/lib/etcd ,需在启动服务前创建这个目录;
  • --name :指定各个节点名称,当 --initial-cluster-state 值为new时, --name的参数值必须位于--initial-cluster 列表中;
  • --cert-file 、 --key-file:etcd server 与 client 通信时使用的证书和私钥;
  • --trusted-ca-file:签名 client 证书的 CA 证书,用于验证 client 证书;
  • --peer-cert-file 、 --peer-key-file:etcd 与 peer 通信使用的证书和私钥;
  • --peer-trusted-ca-file:签名 peer 证书的 CA 证书,用于验证 peer 证书;

3.04 为各节点创建和分发etcd systemd unit文件

[root@k8s-master01 ~]# vi /opt/k8s/script/etcd_service.sh

ETCD_NAMES=("etcd0" "etcd1" "etcd2")
MASTER_IPS=("$1" "$2" "$3")
#替换模板文件中的变量,为各节点创建systemd unit文件
for (( i=0; i < 3; i++ ));do
        sed -e "s/##ETCD_NAME##/${ETCD_NAMES[i]}/g" -e "s/##MASTER_IP##/${MASTER_IPS[i]}/g" /opt/etcd/etcd.service.template > /opt/etcd/etcd-${MASTER_IPS[i]}.service
done
#分发生成的systemd unit和etcd的配置文件:
for master_ip in ${MASTER_IPS[@]};do
        echo ">>> ${master_ip}"
        scp /opt/etcd/etcd-${master_ip}.service root@${master_ip}:/etc/systemd/system/etcd.service
done
[root@k8s-master01 ~]# bash /opt/k8s/script/etcd_service.sh 192.168.2.201 192.168.2.202 192.168.2.203

3.05 启动etcd服务

[root@k8s-master01 ~]# vi /opt/k8s/script/etcd.sh

MASTER_IPS=("$1" "$2" "$3")
#启动 etcd 服务
for master_ip in ${MASTER_IPS[@]};do
        echo ">>> ${master_ip}"
        ssh root@${master_ip} "systemctl daemon-reload && systemctl enable etcd && systemctl start etcd"
done
#检查启动结果,确保状态为 active (running)
for master_ip in ${MASTER_IPS[@]};do
        echo ">>> ${master_ip}"
        ssh root@${master_ip} "systemctl status etcd|grep Active"
done
#验证服务状态,输出均为healthy 时表示集群服务正常
for master_ip in ${MASTER_IPS[@]};do
        echo ">>> ${master_ip}"
        ETCDCTL_API=3 /opt/etcd/bin/etcdctl \
            --endpoints=https://${master_ip}:2379 \
            --cacert=/opt/k8s/cert/ca.pem \
            --cert=/opt/etcd/cert/etcd.pem \
            --key=/opt/etcd/cert/etcd-key.pem endpoint health
done 
[root@k8s-master01 ~]# bash /opt/k8s/script/etcd.sh 192.168.2.201 192.168.2.202 192.168.2.203

4. 部署flannel网络

  • kubernetes要求集群内各节点(包括master节点)能通过Pod网段互联互通。flannel使用vxlan技术为各节点创建一个可以互通的Pod网络,使用的端口为UDP 8472,需要开放该端口(如公有云 AWS 等)。
  • flannel第一次启动时,从etcd获取Pod网段信息,为本节点分配一个未使用的 /24段地址,然后创建 flannel.1(也可能是其它名称) 接口。
  • flannel将分配的Pod网段信息写入/run/flannel/docker文件,docker后续使用这个文件中的环境变量设置docker0网桥。

4.01 下载flannel二进制文件

[root@k8s-master01 ~]# wget https://github.com/coreos/flannel/releases/download/v0.11.0/flannel-v0.11.0-linux-amd64.tar.gz
[root@k8s-master01 ~]# mkdir flanneld
[root@k8s-master01 ~]# tar -xvf flannel-v0.11.0-linux-amd64.tar.gz -C flanneld

4.02 创建flannel证书和密钥

  • flannel从etcd集群存取网段分配信息,而etcd集群启用了双向x509证书认证,所以需要flanneld 生成证书和私钥。

4.02.01 创建证书签名请求

[root@k8s-master01 ~]# cat > /opt/flanneld/cert/flanneld-csr.json <<EOF
{
    "CN": "flanneld",
    "hosts": [],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "ST": "BeiJing",
            "L": "BeiJing",
            "O": "k8s",
            "OU": "steams"
        }
    ]
}
EOF
  • 该证书只会被 kubectl 当做 client 证书使用,所以 hosts 字段为空;

4.02.02 生成证书和密钥

[root@k8s-master01 ~]# cfssl gencert -ca=/opt/k8s/cert/ca.pem -ca-key=/opt/k8s/cert/ca-key.pem -config=/opt/k8s/cert/ca-config.json -profile=kubernetes /opt/flanneld/cert/flanneld-csr.json | cfssljson -bare /opt/flanneld/cert/flanneld

[root@k8s-master01 ~]# ll /opt/flanneld/cert/flanneld*
flanneld.csr       flanneld-csr.json  flanneld-key.pem   flanneld.pem   

4.02.03 将flanneld二进制文件和生成的证书和私钥分发到所有节点(包含node节点!)

[root@k8s-master01 ~]# vi /opt/k8s/script/scp_flanneld.sh

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
    echo ">>> ${master_ip}"
    scp /root/flanneld/flanneld /root/flanneld/mk-docker-opts.sh root@${master_ip}:/opt/flanneld/bin/
    ssh root@${master_ip} "chmod +x /opt/flanneld/bin/*"
    scp /opt/flanneld/cert/flanneld*.pem root@${master_ip}:/opt/flanneld/cert
done
[root@k8s-master01 ~]# bash /opt/k8s/script/scp_flanneld.sh 192.168.2.201 192.168.2.202 192.168.2.203

4.03 向etcd 写入集群Pod网段信息

  • flanneld当前版本(v0.11.0)不支持etcd v3,故需使用etcd v2 API写入配置key和网段数据;
  • 特别注意etcd版本匹配!!!

向etcd 写入集群Pod网段信息(一个节点操作就可以了!)

[root@k8s-master01 ~]# ETCDCTL_API=2 etcdctl \
--endpoints="https://192.168.2.201:2379,https://192.168.2.202:2379,https://192.168.2.203:2379" \
--ca-file=/opt/k8s/cert/ca.pem \
--cert-file=/opt/flanneld/cert/flanneld.pem \
--key-file=/opt/flanneld/cert/flanneld-key.pem \
set /atomic.io/network/config '{"Network":"10.30.0.0/16","SubnetLen": 24, "Backend": {"Type": "vxlan"}}'

# 返回如下信息(写入的Pod网段"Network"必须是/16 段地址,必须与kube-controller-manager的--cluster-cidr参数值一致) 
{"Network":"10.30.0.0/16","SubnetLen": 24, "Backend": {"Type": "vxlan"}}

4.04 创建flanneld的systemd unit文件

[root@k8s-master01 ~]# vi /opt/flanneld/flanneld.service.template

[Unit]
Description=Flanneld overlay address etcd agent
After=network.target
After=network-online.target
Wants=network-online.target
After=etcd.service
Before=docker.service

[Service]
Type=notify
ExecStart=/opt/flanneld/bin/flanneld \
-etcd-cafile=/opt/k8s/cert/ca.pem \
-etcd-certfile=/opt/flanneld/cert/flanneld.pem \
-etcd-keyfile=/opt/flanneld/cert/flanneld-key.pem \
-etcd-endpoints=https://192.168.2.201:2379,https://192.168.2.202:2379,https://192.168.2.203:2379 \
-etcd-prefix=/atomic.io/network \
-iface=eth0
ExecStartPost=/opt/flanneld/bin/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /run/flannel/docker
Restart=on-failure

[Install]
WantedBy=multi-user.target
RequiredBy=docker.service
  • mk-docker-opts.sh脚本将分配给flanneld的Pod子网网段信息写入/run/flannel/docker文件,后续docker启动时使用这个文件中的环境变量配置docker0 网桥;
  • flanneld使用系统缺省路由所在的接口与其它节点通信,对于有多个网络接口(如内网和公网)的节点,可以用-iface参数指定通信接口,如上面的eth1接口;
  • flanneld 运行时需要 root 权限;

4.05 分发flanneld systemd unit文件到所有节点,启动并检查flanneld服务

[root@k8s-master01 ~]# vi /opt/k8s/script/flanneld_service.sh

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
    echo ">>> ${master_ip}"
 #分发 flanneld systemd unit 文件到所有节点
    scp /opt/flanneld/flanneld.service.template root@${master_ip}:/etc/systemd/system/flanneld.service
 #启动 flanneld 服务
    ssh root@${master_ip} "systemctl daemon-reload && systemctl enable flanneld && systemctl restart flanneld"
 #检查启动结果
    ssh root@${master_ip} "systemctl status flanneld|grep Active"
done
[root@k8s-master01 ~]# bash /opt/k8s/script/flanneld_service.sh 192.168.2.201 192.168.2.202 192.168.2.203

4.06 检查分配给各 flanneld 的 Pod 网段信息

# 查看集群 Pod 网段(/16)
[root@k8s-master01 ~]# ETCDCTL_API=2 etcdctl \
--endpoints="https://192.168.2.201:2379,https://192.168.2.202:2379,https://192.168.2.203:2379" \
--ca-file=/opt/k8s/cert/ca.pem \
--cert-file=/opt/flanneld/cert/flanneld.pem \
--key-file=/opt/flanneld/cert/flanneld-key.pem \
get /atomic.io/network/config
# 输出:
{"Network":"10.30.0.0/16","SubnetLen": 24, "Backend": {"Type": "vxlan"}}

# 查看已分配的 Pod 子网段列表(/24)
[root@k8s-master01 ~]# ETCDCTL_API=2 etcdctl \
--endpoints="https://192.168.2.201:2379,https://192.168.2.202:2379,https://192.168.2.203:2379" \
--ca-file=/opt/k8s/cert/ca.pem \
--cert-file=/opt/flanneld/cert/flanneld.pem \
--key-file=/opt/flanneld/cert/flanneld-key.pem \
ls /atomic.io/network/subnets
# 输出:
/atomic.io/network/subnets/10.30.34.0-24
/atomic.io/network/subnets/10.30.41.0-24
/atomic.io/network/subnets/10.30.7.0-24

# 查看某一 Pod 网段对应的节点 IP 和 flannel 接口地址
[root@k8s-master01 ~]# ETCDCTL_API=2 etcdctl \
--endpoints="https://192.168.2.201:2379,https://192.168.2.202:2379,https://192.168.2.203:2379" \
--ca-file=/opt/k8s/cert/ca.pem \
--cert-file=/opt/flanneld/cert/flanneld.pem \
--key-file=/opt/flanneld/cert/flanneld-key.pem \
get /atomic.io/network/subnets/10.30.34.0-24
# 输出:
{"PublicIP":"192.168.2.202","BackendType":"vxlan","BackendData":{"VtepMAC":"e6:b2:85:07:9f:c0"}}

# 验证各节点能通过 Pod 网段互通, 注意输出的pod网段!
[root@k8s-master01 ~]# vi /opt/k8s/script/ping_flanneld.sh
MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
    echo ">>> ${master_ip}"
 #在各节点上部署 flannel 后,检查是否创建了 flannel 接口(名称可能为 flannel0、flannel.0、flannel.1 等)
    ssh ${master_ip} "/usr/sbin/ip addr show flannel.1|grep -w inet"
 #在各节点上 ping 所有 flannel 接口 IP,确保能通
    ssh ${master_ip} "ping -c 1 10.30.34.0"
    ssh ${master_ip} "ping -c 1 10.30.41.0"
    ssh ${master_ip} "ping -c 1 10.30.7.0"
done
# 运行!
[root@k8s-master01 ~]# bash /opt/k8s/script/ping_flanneld.sh 192.168.2.201 192.168.2.202 192.168.2.203

5. 部署kubectl命令行工具

  • kubectl 是 kubernetes 集群的命令行管理工具
  • kubectl 默认从 ~/.kube/config 文件读取 kube-apiserver 地址、证书、用户名等信息,如果没有配置,执行 kubectl 命令时可能会出错:
  • 本文档只需要部署一次,生成的 kubeconfig 文件与机器无关。

5.01 下载kubectl二进制文件, 并分发所有节点(包含node!)

  • kubernetes-server-linux-amd64.tar.gz包含所有组件!
[root@k8s-master01 ~]# wget https://dl.k8s.io/v1.16.2/kubernetes-server-linux-amd64.tar.gz

[root@k8s-master01 ~]# tar -zxvf kubernetes-server-linux-amd64.tar.gz
[root@k8s-master01 ~]# vi /opt/k8s/script/kubectl_environment.sh

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
    echo ">>> ${master_ip}"
    scp /root/kubernetes/server/bin/kubectl root@${master_ip}:/opt/k8s/bin/
done
[root@k8s-master01 ~]# bash /opt/k8s/script/kubectl_environment.sh 192.168.2.201 192.168.2.202 192.168.2.203

5.02 创建 admin 证书和私钥

  • kubectl 与 apiserver https 安全端口通信,apiserver 对提供的证书进行认证和授权。
  • kubectl 作为集群的管理工具,需要被授予最高权限。这里创建具有最高权限的admin 证书。

创建证书签名请求

[root@k8s-master01 ~]# cat > /opt/k8s/cert/admin-csr.json <<EOF
{
    "CN": "admin",
    "hosts": [],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "ST": "BeiJing",
            "L": "BeiJing",
            "O": "system:masters",
            "OU": "steams"
        }
    ]
}
EOF
  • O 为 system:masters ,kube-apiserver 收到该证书后将请求的 Group 设置为system:masters;
  • 预定义的 ClusterRoleBinding cluster-admin 将 Group system:masters 与Role cluster-admin 绑定,该 Role 授予所有 API的权限;
  • 该证书只会被 kubectl 当做 client 证书使用,所以 hosts 字段为空;

生成证书和私钥

[root@k8s-master01 ~]# cfssl gencert -ca=/opt/k8s/cert/ca.pem \
-ca-key=/opt/k8s/cert/ca-key.pem \
-config=/opt/k8s/cert/ca-config.json \
-profile=kubernetes /opt/k8s/cert/admin-csr.json | cfssljson -bare /opt/k8s/cert/admin

[root@k8s-master01 ~]# ll /opt/k8s/cert/admin*
admin.csr       admin-csr.json  admin-key.pem   admin.pem  

5.03 创建和分发 kubeconfig 文件

5.03.01 创建kubeconfig文件

  • kubeconfig 为 kubectl 的配置文件,包含访问 apiserver 的所有信息,如 apiserver 地址、CA 证书和自身使用的证书;

step.1 设置集群参数, --server=${KUBE_APISERVER}, 指定IP和端口; 本文使用的是haproxy的VIP和端口;如果没有haproxy代理,就用实际服务的IP和端口!

[root@k8s-master01 ~]# kubectl config set-cluster kubernetes \
--certificate-authority=/opt/k8s/cert/ca.pem \
--embed-certs=true \
--server=https://192.168.2.210:8443 \
--kubeconfig=/root/.kube/kubectl.kubeconfig

step.2 设置客户端认证参数

[root@k8s-master01 ~]# kubectl config set-credentials kube-admin \
--client-certificate=/opt/k8s/cert/admin.pem \
--client-key=/opt/k8s/cert/admin-key.pem \
--embed-certs=true \
--kubeconfig=/root/.kube/kubectl.kubeconfig

step.3 设置上下文参数

[root@k8s-master01 ~]#  kubectl config set-context kube-admin@kubernetes \
--cluster=kubernetes \
--user=kube-admin \
--kubeconfig=/root/.kube/kubectl.kubeconfig

step.4设置默认上下文

[root@k8s-master01 ~]# kubectl config use-context kube-admin@kubernetes --kubeconfig=/root/.kube/kubectl.kubeconfig

--certificate-authority :验证 kube-apiserver 证书的根证书;
--client-certificate 、 --client-key :刚生成的 admin 证书和私钥,连接 kube-apiserver 时使用;
--embed-certs=true :将 ca.pem 和 admin.pem 证书内容嵌入到生成的kubectl.kubeconfig 文件中(不加时,写入的是证书文件路径);

5.03.02 验证kubeconfig文件

[root@k8s-master01 ~]# kubectl config view --kubeconfig=/root/.kube/kubectl.kubeconfig
apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: DATA+OMITTED
    server: https://192.168.2.210:8443
  name: kubernetes
contexts:
- context:
    cluster: kubernetes
    user: kube-admin
  name: kube-admin@kubernetes
current-context: kube-admin@kubernetes
kind: Config
preferences: {}
users:
- name: kube-admin
  user:
    client-certificate-data: REDACTED
    client-key-data: REDACTED

5.03.03 分发 kubeclt 和kubeconfig 文件,分发到所有使用kubectl 命令的节点

[root@k8s-master01 ~]# vi /opt/k8s/script/scp_kubectl_config.sh

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
    echo ">>> ${master_ip}"
    scp /root/kubernetes/server/bin/kubectl root@${master_ip}:/opt/k8s/bin/
    ssh root@${master_ip} "chmod +x /opt/k8s/bin/*"
    scp /root/.kube/kubectl.kubeconfig root@${master_ip}:/root/.kube/config
done
[root@k8s-master01 ~]# bash /opt/k8s/script/scp_kubectl_config.sh 192.168.2.201 192.168.2.202 192.168.2.203

6. 部署master节点

  • kubernetes master 节点运行如下组件:
    kube-apiserver
    kube-scheduler
    kube-controller-manager

  • kube-scheduler 和 kube-controller-manager 可以以集群模式运行,通过 leader 选举产生一个工作进程,其它进程处于阻塞模式。
  • 对于 kube-apiserver,可以运行多个实例, 但对其它组件需要提供统一的访问地址,该地址需要高可用。本文档使用 keepalived 和 haproxy 实现 kube-apiserver VIP 高可用和负载均衡。
  • 因为对master做了keepalived高可用,所以3台服务器都有可能会升成master服务器(主master宕机,会有从升级为主);因此所有的master操作,在3个服务器上都要进行。

下载最新版本的二进制文件, 想办法!!!

[root@k8s-master01 ~]# wget https://dl.k8s.io/v1.16.2/kubernetes-server-linux-amd64.tar.gz

[root@k8s-master01 ~]# wget https://dl.k8s.io/v1.16.2/kubernetes-server-linux-amd64.tar.gz

将二进制文件拷贝到所有 master 节点

[root@k8s-master01 ~]# vi /opt/k8s/script/scp_master.sh

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
    echo ">>> ${master_ip}"
    scp /root/kubernetes/server/bin/{kube-apiserver,kube-controller-manager,kube-scheduler} root@${master_ip}:/opt/k8s/bin/
    ssh root@${master_ip} "chmod +x /opt/k8s/bin/*"
done
[root@k8s-master01 ~]# bash /opt/k8s/script/scp_master.sh 192.168.2.201 192.168.2.202 192.168.2.203

6.01 部署高可用组件

  • 本文档讲解使用 keepalived 和 haproxy 实现 kube-apiserver 高可用的步骤:
    keepalived 提供 kube-apiserver 对外服务的 VIP;
    haproxy 监听 VIP,后端连接所有 kube-apiserver 实例,提供健康检查和负载均衡功能;
  • 运行 keepalived 和 haproxy 的节点称为 LB 节点。由于 keepalived 是一主多备运行模式,故至少两个 LB 节点。
  • 本文档复用 master 节点的三台机器,haproxy 监听的端口(8443) 需要与 kube-apiserver的端口 6443 不同,避免冲突。
  • keepalived 在运行过程中周期检查本机的 haproxy 进程状态,如果检测到 haproxy 进程异常,则触发重新选主的过程,VIP 将飘移到新选出来的主节点,从而实现 VIP 的高可用。
  • 所有组件(如 kubeclt、apiserver、controller-manager、scheduler 等)都通过 VIP 和haproxy 监听的 8443 端口访问 kube-apiserver 服务。

6.01.01 安装软件包,配置haproxy 配置文件

[root@k8s-master01 ~]# yum install keepalived haproxy -y

[root@k8s-master01 ~]# vi /etc/haproxy/haproxy.cfg 
global
    log /dev/log local0
    log /dev/log local1 notice
    chroot /var/lib/haproxy
    stats socket /var/run/haproxy-admin.sock mode 660 level admin
    stats timeout 30s
    user haproxy
    group haproxy
    daemon
    nbproc 1
defaults
    log global
    timeout connect 5000
    timeout client 10m
    timeout server 10m
listen admin_stats
    bind 0.0.0.0:10080
    mode http
    log 127.0.0.1 local0 err
    stats refresh 30s
    stats uri /status
    stats realm welcome login\ Haproxy
    stats auth haproxy:123456
    stats hide-version
    stats admin if TRUE
listen k8s-master
    bind 0.0.0.0:8443
    mode tcp
    option tcplog
    balance source
    server 192.168.2.201 192.168.2.201:6443 check inter 2000 fall 2 rise 2 weight 1
    server 192.168.2.202 192.168.2.202:6443 check inter 2000 fall 2 rise 2 weight 1
    server 192.168.2.203 192.168.2.203:6443 check inter 2000 fall 2 rise 2 weight 1
  • haproxy 在 10080 端口输出 status 信息;
  • haproxy 监听所有接口的 8443 端口,该端口与环境变量 ${KUBE_APISERVER} 指定的端口必须一致;
  • server 字段列出所有kube-apiserver监听的 IP 和端口;

6.01.02 在其他服务器安装、下发haproxy 配置文件;并启动检查haproxy服务

[root@k8s-master01 ~]# vi /opt/k8s/script/haproxy.sh

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
    echo ">>> ${master_ip}"
 #安装haproxy
    ssh root@${master_ip} "yum install -y keepalived haproxy"
 #下发配置文件
    scp /etc/haproxy/haproxy.cfg root@${master_ip}:/etc/haproxy
 #启动检查haproxy服务
    ssh root@${master_ip} "systemctl restart haproxy"
    ssh root@${master_ip} "systemctl enable haproxy.service"
    ssh root@${master_ip} "systemctl status haproxy|grep Active"
 #检查 haproxy 是否监听6443 端口
    ssh root@${master_ip} "netstat -lnpt|grep haproxy"
done
[root@k8s-master01 ~]# bash /opt/k8s/script/haproxy.sh 192.168.2.201 192.168.2.202 192.168.2.203

输出类似:

Active: active (running) since Tue 2019-11-12 01:54:41 CST; 543ms ago
tcp        0      0 0.0.0.0:8443            0.0.0.0:*               LISTEN      4995/haproxy        
tcp        0      0 0.0.0.0:10080           0.0.0.0:*               LISTEN      4995/haproxy   

6.01.03 配置和启动 keepalived 服务

  • keepalived 是一主(master)多备(backup)运行模式,故有两种类型的配置文件。
  • master 配置文件只有一份,backup 配置文件视节点数目而定,对于本文档而言,规划如下:
    master: 192.168.2.201
    backup:192.168.2.202、192.168.2.203

在192.168.2.201 master主服务;配置文件:

[root@k8s-master01 ~]# vim /etc/keepalived/keepalived.conf

global_defs {
    router_id keepalived_ha_121
}
vrrp_script check-haproxy {
    script "killall -0 haproxy"
    interval 5
    weight -30
}
vrrp_instance VI-k8s-master {
    state MASTER
    priority 120    # 第一台从为110, 以此类推!
    dont_track_primary
    interface eth0
    virtual_router_id 121
    advert_int 3
    track_script {
        check-haproxy
    }
    virtual_ipaddress {
        192.168.2.210
    }
}
  • 我的VIP 所在的接口nterface 为 eth0;根据自己的情况改变
  • 使用 killall -0 haproxy 命令检查所在节点的 haproxy 进程是否正常。如果异常则将权重减少(-30),从而触发重新选主过程;
  • router_id、virtual_router_id 用于标识属于该 HA 的 keepalived 实例,如果有多套keepalived HA,则必须各不相同;

在192.168.2.202, 192.168.2.203两台backup 服务;配置文件:

[root@k8s-master02 ~]# vi /etc/keepalived/keepalived.conf

global_defs {
        router_id keepalived_ha_122_123
}
vrrp_script check-haproxy {
        script "killall -0 haproxy"
        interval 5
        weight -30
}
vrrp_instance VI-k8s-master {
        state BACKUP
        priority 110   # 第2台从为100
        dont_track_primary
        interface eth0
        virtual_router_id 121
        advert_int 3
        track_script {
        check-haproxy
        }
        virtual_ipaddress {
            192.168.2.210
        }
}
  • priority 的值必须小于 master 的值;两个从的值也需要不一样;

开启keepalived 服务

[root@k8s-master01 ~]# systemctl restart keepalived && systemctl enable keepalived && systemctl status keepalived
[root@k8s-master01 ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:15:5d:00:68:05 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.101/24 brd 192.168.2.255 scope global noprefixroute eth0
       valid_lft forever preferred_lft forever
    inet 192.168.2.10/32 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::f726:9d22:2b89:694c/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: flannel.1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UNKNOWN group default 
    link/ether aa:43:e5:bb:88:28 brd ff:ff:ff:ff:ff:ff
    inet 10.30.34.0/32 scope global flannel.1
       valid_lft forever preferred_lft forever
    inet6 fe80::a843:e5ff:febb:8828/64 scope link 
       valid_lft forever preferred_lft forever
  • 在master主服务器上能看到eth0网卡上已经有VIP的IP地址存在

6.01.04 查看 haproxy 状态页面

  • 浏览器访问 192.168.2.210:10080/status 地址

6.02 部署 kube-apiserver 组件

下载二进制文件

  • kubernetes_server 包里有, 已经解压到/opt/k8s/bin下

6.02.01 创建 kube-apiserver证书和私钥

创建证书签名请求(host地址多加几个备用--> "192.168.2.8","192.168.2.9")

[root@k8s-master01 ~]# cat > /opt/k8s/cert/kube-apiserver-csr.json <<EOF
{
    "CN": "kubernetes",
    "hosts": [
        "127.0.0.1",
        "10.96.0.1",
        "192.168.2.210",
        "192.168.2.201",
        "192.168.2.202",
        "192.168.2.203",
        "192.168.2.8",
        "192.168.2.9"
        "kubernetes",
        "kubernetes.default",
        "kubernetes.default.svc",
        "kubernetes.default.svc.cluster",
        "kubernetes.default.svc.cluster.local"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
          "C": "CN",
          "ST": "BeiJing",
          "L": "BeiJing",
          "O": "k8s",
          "OU": "steams"
        }
    ]
}
EOF
  • hosts 字段指定授权使用该证书的 IP 或域名列表,这里列出了 VIP 、apiserver节点 IP、kubernetes 服务 IP 和域名;
  • 域名最后字符不能是 . (如不能为kubernetes.default.svc.cluster.local. ),否则解析时失败,提示: x509:cannot parse dnsName "kubernetes.default.svc.cluster.local." ;
  • 如果使用非 cluster.local 域名,如 opsnull.com ,则需要修改域名列表中的最后两个域名为: kubernetes.default.svc.opsnull 、 kubernetes.default.svc.opsnull.com
  • kubernetes 服务 IP 是 apiserver 自动创建的,一般是 --service-cluster-ip-range 参数指定的网段的第一个IP,后续可以通过如下命令获取:
    kubectl get svc kubernetes

生成证书和私钥

[root@k8s-master01 ~]# cfssl gencert -ca=/opt/k8s/cert/ca.pem \
-ca-key=/opt/k8s/cert/ca-key.pem \
-config=/opt/k8s/cert/ca-config.json \
-profile=kubernetes /opt/k8s/cert/kube-apiserver-csr.json | cfssljson -bare /opt/k8s/cert/kube-apiserver

[root@k8s-master01 ~]# ll /opt/k8s/cert/kube-apiserver*
kube-apiserver.csr      kube-apiserver-csr.json  kube-apiserver-key.pem  kube-apiserver.pem 

6.02.02 创建加密配置文件

产生一个用来加密Etcd 的 Key:

[root@k8s-master01 ~]# head -c 32 /dev/urandom | base64
# 返回一个key, 每台master节点需要用一样的 Key!!!
muqIUutYDd5ARLtsg/W1CYWs3g8Fq9uJO/lDpSsv9iw=

使用这个加密的key,创建加密配置文件

[root@k8s-master01 ~]# vi encryption-config.yaml

kind: EncryptionConfig
apiVersion: v1
resources:
  - resources:
      - secrets
    providers:
      - aescbc:
          keys:
            - name: key1
              secret: muqIUutYDd5ARLtsg/W1CYWs3g8Fq9uJO/lDpSsv9iw=
      - identity: {}

6.02.03 将生成的证书和私钥文件、加密配置文件拷贝到master节点的/opt/k8s目录下

[root@k8s-master01 ~]# vi /opt/k8s/script/scp_apiserver.sh

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
    echo  ">>> ${master_ip}"
    scp /opt/k8s/cert/kube-apiserver*.pem root@${master_ip}:/opt/k8s/cert/
    scp /root/encryption-config.yaml root@${master_ip}:/opt/k8s/
done 
[root@k8s-master01 ~]# bash /opt/k8s/script/scp_apiserver.sh 192.168.2.201 192.168.2.202 192.168.2.203

6.02.04 创建 kube-apiserver 的 systemd unit 模板文件

[root@k8s-master01 ~]# vi /opt/k8s/kube-apiserver/kube-apiserver.service.template

[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target

[Service]
ExecStart=/opt/k8s/bin/kube-apiserver \
--enable-admission-plugins=NamespaceLifecycle,NodeRestriction,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota \
--anonymous-auth=false \
--experimental-encryption-provider-config=/opt/k8s/encryption-config.yaml \
--advertise-address=##MASTER_IP## \
--bind-address=##MASTER_IP## \
--insecure-port=0 \
--secure-port=6443 \
--authorization-mode=Node,RBAC \
--runtime-config=api/all \
--enable-bootstrap-token-auth \
--service-cluster-ip-range=10.96.0.0/16 \
--service-node-port-range=30000-50000 \
--tls-cert-file=/opt/k8s/cert/kube-apiserver.pem \
--tls-private-key-file=/opt/k8s/cert/kube-apiserver-key.pem \
--client-ca-file=/opt/k8s/cert/ca.pem \
--kubelet-client-certificate=/opt/k8s/cert/kube-apiserver.pem \
--kubelet-client-key=/opt/k8s/cert/kube-apiserver-key.pem \
--service-account-key-file=/opt/k8s/cert/ca-key.pem \
--etcd-cafile=/opt/k8s/cert/ca.pem \
--etcd-certfile=/opt/k8s/cert/kube-apiserver.pem \
--etcd-keyfile=/opt/k8s/cert/kube-apiserver-key.pem \
--etcd-servers=https://192.168.2.201:2379,https://192.168.2.202:2379,https://192.168.2.203:2379 \
--enable-swagger-ui=true \
--allow-privileged=true \
--apiserver-count=3 \
--audit-log-maxage=30 \
--audit-log-maxbackup=3 \
--audit-log-maxsize=100 \
--audit-log-path=/var/log/kube-apiserver-audit.log \
--event-ttl=1h \
--alsologtostderr=true \
--logtostderr=false \
--log-dir=/var/log/kubernetes \
--v=2
Restart=on-failure
RestartSec=5
Type=notify
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
  • -experimental-encryption-provider-config :启用加密特性;
  • --authorization-mode=Node,RBAC : 开启 Node 和 RBAC 授权模式,拒绝未授权的请求;
  • --enable-admission-plugins :启用 ServiceAccount 和NodeRestriction ;
  • --service-account-key-file :签名 ServiceAccount Token 的公钥文件,kube-controller-manager 的 --service-account-private-key-file 指定私钥文件,两者配对使用;
  • --tls-*-file :指定 apiserver 使用的证书、私钥和 CA 文件。 --client-ca-file 用于验证 client (kue-controller-manager、kube-scheduler、kubelet、kube-proxy 等)请求所带的证书;
  • --kubelet-client-certificate 、 --kubelet-client-key :如果指定,则使用 https 访问 kubelet APIs;需要为证书对应的用户定义 RBAC 规则,否则访问 kubelet API 时提示未授权;
  • --bind-address : 不能为 127.0.0.1 ,否则外界不能访问它的安全端口6443;
  • --insecure-port=0 :关闭监听非安全端口(8080);
  • --service-cluster-ip-range : 指定 Service Cluster IP 地址段;
  • --service-node-port-range : 指定 NodePort 的端口范围;
  • --runtime-config=api/all=true : 启用所有版本的 APIs,如autoscaling/v2alpha1;
  • --enable-bootstrap-token-auth :启用 kubelet bootstrap 的 token 认证;
  • --apiserver-count=3 :指定集群运行模式,多台 kube-apiserver 会通过 leader选举产生一个工作节点,其它节点处于阻塞状态;

6.02.05 为各master节点创建和分发 kube-apiserver的systemd unit文件; 启动检查 kube-apiserver 服务

[root@k8s-master01 ~]# vi /opt/k8s/script/apiserver_service.sh

MASTER_IPS=("$1" "$2" "$3")
#替换模板文件中的变量,为各节点创建 systemd unit 文件
for (( i=0; i < 3; i++ ));do
    sed "s/##MASTER_IP##/${MASTER_IPS[i]}/" /opt/k8s/kube-apiserver/kube-apiserver.service.template > /opt/k8s/kube-apiserver/kube-apiserver-${MASTER_IPS[i]}.service
done
#启动并检查 kube-apiserver 服务
for master_ip in ${MASTER_IPS[@]};do
    echo ">>> ${master_ip}"
    scp /opt/k8s/kube-apiserver/kube-apiserver-${master_ip}.service root@${master_ip}:/etc/systemd/system/kube-apiserver.service
    ssh root@${master_ip} "systemctl daemon-reload && systemctl enable kube-apiserver && systemctl restart kube-apiserver"
    ssh root@${master_ip} "systemctl status kube-apiserver |grep 'Active:'"
done
[root@k8s-master01 ~]# bash /opt/k8s/script/apiserver_service.sh 192.168.2.201 192.168.2.202 192.168.2.203

6.02.06 打印 kube-apiserver 写入 etcd 的数据

[root@k8s-master01 ~]# ETCDCTL_API=3 etcdctl \
--endpoints="https://192.168.2.201:2379,https://192.168.2.202:2379,https://192.168.2.203:2379" \
--cacert=/opt/k8s/cert/ca.pem \
--cert=/opt/etcd/cert/etcd.pem \
--key=/opt/etcd/cert/etcd-key.pem \
get /registry/ --prefix --keys-only

6.02.07 检查集群信息

[root@k8s-master01 ~]# kubectl cluster-info
Kubernetes master is running at https://192.168.2.210:8443

[root@k8s-master01 ~]# kubectl get all --all-namespaces
NAMESPACE   NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
default     service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   49m

# 6443: 接收 https 请求的安全端口,对所有请求做认证和授权;
# 由于关闭了非安全端口,故没有监听 8080;
[root@k8s-master01 ~]# ss -nutlp |grep apiserver
tcp    LISTEN   0        128         192.168.2.201:6443           0.0.0.0:*      users:(("kube-apiserver",pid=4425,fd=6)) 

6.03 部署高可用kube-controller-manager 集群

  • 该集群包含 3 个节点,启动后将通过竞争选举机制产生一个 leader 节点,其它节点为阻塞状态。当 leader 节点不可用后,剩余节点将再次进行选举产生新的 leader 节点,从而保证服务的可用性。
  • 为保证通信安全,本文档先生成 x509 证书和私钥,kube-controller-manager 在如下两种情况下使用该证书:
    与 kube-apiserver 的安全端口通信时;
    在安全端口(https,10252) 输出 prometheus 格式的 metrics;

准备工作:下载kube-controller-manager二进制文件(包含在kubernetes-server包里, 已解压发送)

6.03.01 创建 kube-controller-manager 证书和私钥

创建证书签名请求:

[root@k8s-master01 ~]# cat > /opt/k8s/cert/kube-controller-manager-csr.json <<EOF
{
    "CN": "system:kube-controller-manager",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "hosts": [
        "127.0.0.1",
        "192.168.2.201",
        "192.168.2.202",
        "192.168.2.203"
    ],
    "names": [
        {
            "C": "CN",
            "ST": "BeiJing",
            "L": "BeiJing",
            "O": "system:kube-controller-manager",
            "OU": "steams"
        }
    ]
}
EOF
  • hosts 列表包含所有 kube-controller-manager 节点 IP;
  • CN 为 system:kube-controller-manager、O 为 system:kube-controller-manager(kubernetes 内置的 ClusterRoleBindings system:kube-controller-manager 赋予kube-controller-manager 工作所需的权限.)

生成证书和私钥

cfssl gencert -ca=/opt/k8s/cert/ca.pem \
-ca-key=/opt/k8s/cert/ca-key.pem \
-config=/opt/k8s/cert/ca-config.json \
-profile=kubernetes /opt/k8s/cert/kube-controller-manager-csr.json | cfssljson -bare /opt/k8s/cert/kube-controller-manager

[root@k8s-master01 ~]# ll /opt/k8s/cert/kube-controller-manager*
kube-controller-manager.csr       kube-controller-manager-csr.json  kube-controller-manager-key.pem   kube-controller-manager.pem  

6.03.02 创建.kubeconfig 文件

  • kubeconfig 文件包含访问 apiserver 的所有信息,如 apiserver 地址、CA 证书和自身使用的证书;

执行命令,生成kube-controller-manager.kubeconfig文件

# step.1 设置集群参数:
[root@k8s-master01 ~]# kubectl config set-cluster kubernetes \
--certificate-authority=/opt/k8s/cert/ca.pem \
--embed-certs=true \
--server=https://192.168.2.210:8443 \
--kubeconfig=/opt/k8s/kube-controller-manager/kube-controller-manager.kubeconfig

# step.2 设置客户端认证参数
[root@k8s-master01 ~]# kubectl config set-credentials system:kube-controller-manager \
--client-certificate=/opt/k8s/cert/kube-controller-manager.pem \
--client-key=/opt/k8s/cert/kube-controller-manager-key.pem \
--embed-certs=true \
--kubeconfig=/opt/k8s/kube-controller-manager/kube-controller-manager.kubeconfig

# step.3 设置上下文参数
[root@k8s-master01 ~]# kubectl config set-context system:kube-controller-manager@kubernetes \
--cluster=kubernetes \
--user=system:kube-controller-manager \
--kubeconfig=/opt/k8s/kube-controller-manager/kube-controller-manager.kubeconfig

# tep.4 设置默认上下文
[root@k8s-master01 ~]# kubectl config use-context system:kube-controller-manager@kubernetes \
--kubeconfig=/opt/k8s/kube-controller-manager/kube-controller-manager.kubeconfig

验证kube-controller-manager.kubeconfig文件

[root@k8s-master01 ~]# kubectl config view --kubeconfig=/opt/k8s/kube-controller-manager/kube-controller-manager.kubeconfig
apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: DATA+OMITTED
    server: https://192.168.2.210:8443
  name: kubernetes
contexts:
- context:
    cluster: kubernetes
    user: system:kube-controller-manager
  name: system:kube-controller-manager@kubernetes
current-context: system:kube-controller-manager@kubernetes
kind: Config
preferences: {}
users:
- name: system:kube-controller-manager
  user:
    client-certificate-data: REDACTED
    client-key-data: REDACTED

分发生成的证书和私钥、kubeconfig 到所有 master 节点

[root@k8s-master01 ~]# vi /opt/k8s/script/scp_controller_manager.sh

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
    echo ">>> ${master_ip}"
    scp /opt/k8s/cert/kube-controller-manager*.pem root@${master_ip}:/opt/k8s/cert/
    scp /opt/k8s/kube-controller-manager/kube-controller-manager.kubeconfig root@${master_ip}:/opt/k8s/kube-controller-manager/
done
[root@k8s-master01 ~]# bash /opt/k8s/script/scp_controller_manager.sh 192.168.2.201 192.168.2.202 192.168.2.203

6.03.03 创建和分发 kube-controller-manager 的 systemd unit 文件

[root@k8s-master01 ~]# vi /opt/k8s/kube-controller-manager/kube-controller-manager.service.template

[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/GoogleCloudPlatform/kubernetes

[Service]
ExecStart=/opt/k8s/bin/kube-controller-manager \
--port=0 \
--secure-port=10252 \
--bind-address=127.0.0.1 \
--kubeconfig=/opt/k8s/kube-controller-manager/kube-controller-manager.kubeconfig \
--service-cluster-ip-range=10.96.0.0/16 \
--cluster-name=kubernetes \
--cluster-signing-cert-file=/opt/k8s/cert/ca.pem \
--cluster-signing-key-file=/opt/k8s/cert/ca-key.pem \
--experimental-cluster-signing-duration=876000h \
--root-ca-file=/opt/k8s/cert/ca.pem \
--service-account-private-key-file=/opt/k8s/cert/ca-key.pem \
--leader-elect=true \
--feature-gates=RotateKubeletServerCertificate=true \
--controllers=*,bootstrapsigner,tokencleaner \
--horizontal-pod-autoscaler-use-rest-clients=true \
--horizontal-pod-autoscaler-sync-period=10s \
--tls-cert-file=/opt/k8s/cert/kube-controller-manager.pem \
--tls-private-key-file=/opt/k8s/cert/kube-controller-manager-key.pem \
--use-service-account-credentials=true \
--alsologtostderr=true \
--logtostderr=false \
--log-dir=/var/log/kubernetes \
--v=2
Restart=on
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
  • --port=0:关闭监听 http /metrics 的请求,同时 --address 参数无效,--bind-address 参数有效;
  • --secure-port=10252、--bind-address=0.0.0.0: 在所有网络接口监听 10252 端口的 https /metrics 请求;
  • --kubeconfig:指定 kubeconfig 文件路径,kube-controller-manager 使用它连接和验证 kube-apiserver;
  • --cluster-signing-*-file:签名 TLS Bootstrap 创建的证书;
  • --experimental-cluster-signing-duration:指定 TLS Bootstrap 证书的有效期;
  • --root-ca-file:放置到容器 ServiceAccount 中的 CA 证书,用来对 kube-apiserver 的证书进行校验;
  • --service-account-private-key-file:签名 ServiceAccount 中 Token 的私钥文件,必须和 kube-apiserver 的 --service-account-key-file 指定的公钥文件配对使用;
  • --service-cluster-ip-range :指定 Service Cluster IP 网段,必须和 kube-apiserver 中的同名参数一致;
  • --leader-elect=true:集群运行模式,启用选举功能;被选为 leader 的节点负责处理工作,其它节点为阻塞状态;
  • --feature-gates=RotateKubeletServerCertificate=true:开启 kublet server 证书的自动更新特性;
  • --controllers=*,bootstrapsigner,tokencleaner:启用的控制器列表,tokencleaner 用于自动清理过期的 Bootstrap token;
  • --horizontal-pod-autoscaler-*:custom metrics 相关参数,支持 autoscaling/v2alpha1;
  • --tls-cert-file、--tls-private-key-file:使用 https 输出 metrics 时使用的 Server 证书和秘钥;
  • --use-service-account-credentials=true:

6.03.04 kube-controller-manager 的权限

  • ClusteRole: system:kube-controller-manager 的权限很小,只能创建 secret、serviceaccount 等资源对象,各 controller 的权限分散到 ClusterRole system:controller:XXX 中。
  • 需要在 kube-controller-manager 的启动参数中添加 --use-service-account-credentials=true 参数,这样 main controller 会为各 controller 创建对应的 ServiceAccount XXX-controller。
  • 内置的 ClusterRoleBinding system:controller:XXX 将赋予各 XXX-controller ServiceAccount 对应的 ClusterRole system:controller:XXX 权限。

6.03.05 分发systemd unit 文件到所有master 节点;启动检查 kube-controller-manager 服务

[root@k8s-master01 ~]# vi /opt/k8s/script/controller_manager_service.sh

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
        echo ">>> ${master_ip}"
        scp /opt/k8s/kube-controller-manager/kube-controller-manager.service.template root@${master_ip}:/etc/systemd/system/kube-controller-manager.service
        ssh root@${master_ip} "systemctl daemon-reload && systemctl enable kube-controller-manager && systemctl start kube-controller-manager "
        ssh root@${master_ip} "systemctl status kube-controller-manager|grep Active"
done
[root@k8s-master01 ~]# bash /opt/k8s/script/controller_manager_service.sh 192.168.2.201 192.168.2.202 192.168.2.203

6.03.6 查看输出的 metric

[root@k8s-master01 ~]# ss -nutlp |grep kube-controll
tcp    LISTEN   0        128             127.0.0.1:10252          0.0.0.0:*      users:(("kube-controller",pid=9382,fd=6))  

6.03.07 测试 kube-controller-manager 集群的高可用

  • 停掉一个或两个节点的 kube-controller-manager 服务,观察其它节点的日志,看是否获取了 leader 权限。
  • 查看当前的 leader
[root@k8s-master02 ~]# kubectl get endpoints kube-controller-manager --namespace=kube-system -o yaml

6.04 部署高可用 kube-scheduler 集群

  • 该集群包含 3 个节点,启动后将通过竞争选举机制产生一个 leader 节点,其它节点为阻塞状态。当 leader 节点不可用后,剩余节点将再次进行选举产生新的 leader 节点,从而保证服务的可用性。
  • 为保证通信安全,本文档先生成 x509 证书和私钥,kube-scheduler 在如下两种情况下使用该证书:
    与 kube-apiserver 的安全端口通信;
    在安全端口(https,10251) 输出 prometheus 格式的 metrics;

准备工作:下载kube-scheduler 的二进制文件---^^^

6.04.01 创建 kube-scheduler 证书和私钥

创建证书签名请求:

[root@k8s-master01 ~]# cat > /opt/k8s/cert/kube-scheduler-csr.json <<EOF
{
    "CN": "system:kube-scheduler",
    "hosts": [
      "127.0.0.1",
      "192.168.2.201",
      "192.168.2.202",
      "192.168.2.203"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
      {
        "C": "CN",
        "ST": "BeiJing",
        "L": "BeiJing",
        "O": "system:kube-scheduler",
        "OU": "steams"
      }
    ]
}
EOF
  • hosts 列表包含所有 kube-scheduler 节点 IP;
  • CN 为 system:kube-scheduler、O 为 system:kube-scheduler (kubernetes 内置的 ClusterRoleBindings system:kube-scheduler 将赋予 kube-scheduler 工作所需的权限.)

生成证书和私钥

[root@k8s-master01 ~]# cfssl gencert -ca=/opt/k8s/cert/ca.pem \
-ca-key=/opt/k8s/cert/ca-key.pem \
-config=/opt/k8s/cert/ca-config.json \
-profile=kubernetes /opt/k8s/cert/kube-scheduler-csr.json | cfssljson -bare /opt/k8s/cert/kube-scheduler

[root@k8s-master01 ~]# ll /opt/k8s/cert/kube-scheduler*
kube-scheduler.csr       kube-scheduler-csr.json  kube-scheduler-key.pem   kube-scheduler.pem  

6.04.02 创建kubeconfig 文件

  • kubeconfig 文件包含访问 apiserver 的所有信息,如 apiserver 地址、CA 证书和自身使用的证书;

执行命令,生成kube-scheduler.kubeconfig文件

# step.1 设置集群参数
[root@k8s-master01 ~]# kubectl config set-cluster kubernetes \
--certificate-authority=/opt/k8s/cert/ca.pem \
--embed-certs=true \
--server=https://192.168.2.210:8443 \
--kubeconfig=/opt/k8s/kube-scheduler/kube-scheduler.kubeconfig

# step.2 设置客户端认证参数
[root@k8s-master01 ~]# kubectl config set-credentials system:kube-scheduler \
--client-certificate=/opt/k8s/cert/kube-scheduler.pem \
--client-key=/opt/k8s/cert/kube-scheduler-key.pem \
--embed-certs=true  \
--kubeconfig=/opt/k8s/kube-scheduler/kube-scheduler.kubeconfig

# step.3 设置上下文参数
[root@k8s-master01 ~]# kubectl config set-context system:kube-scheduler@kubernetes \
--cluster=kubernetes \
--user=system:kube-scheduler \
--kubeconfig=/opt/k8s/kube-scheduler/kube-scheduler.kubeconfig

# step.4设置默认上下文
[root@k8s-master01 ~]# kubectl config use-context system:kube-scheduler@kubernetes \
--kubeconfig=/opt/k8s/kube-scheduler/kube-scheduler.kubeconfig

验证kube-controller-manager.kubeconfig文件

[root@k8s-master01 ~]# kubectl config view --kubeconfig=/opt/k8s/kube-scheduler/kube-scheduler.kubeconfig
apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: DATA+OMITTED
    server: https://192.168.2.210:8443
  name: kubernetes
contexts:
- context:
    cluster: kubernetes
    user: system:kube-scheduler
  name: system:kube-scheduler@kubernetes
current-context: system:kube-scheduler@kubernetes
kind: Config
preferences: {}
users:
- name: system:kube-scheduler
  user:
    client-certificate-data: REDACTED
    client-key-data: REDACTED

6.04.03 分发生成的证书和私钥、kubeconfig 到所有 master 节点

[root@k8s-master01 ~]# vi /opt/k8s/script/scp_scheduler.sh

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
        echo ">>> ${master_ip}"
        scp /opt/k8s/cert/kube-scheduler*.pem root@${master_ip}:/opt/k8s/cert/
        scp /opt/k8s/kube-scheduler/kube-scheduler.kubeconfig root@${master_ip}:/opt/k8s/kube-scheduler/
done
[root@k8s-master01 ~]# bash /opt/k8s/script/scp_scheduler.sh 192.168.2.201 192.168.2.202 192.168.2.203

6.04.04 创建kube-scheduler 的 systemd unit 文件

[root@k8s-master01 ~]# vi /opt/k8s/kube-scheduler/kube-scheduler.service.template

[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/GoogleCloudPlatform/kubernetes

[Service]
ExecStart=/opt/k8s/bin/kube-scheduler \
  --address=127.0.0.1 \
  --kubeconfig=/opt/k8s/kube-scheduler/kube-scheduler.kubeconfig \
  --leader-elect=true \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=2
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
  • ps: kube-scheduler目前仅支持http, 所以少了一大推相关安全设定!
  • --address:在 127.0.0.1:10251 端口接收 http /metrics 请求;kube-scheduler 目前还不支持接收 https 请求;
  • --kubeconfig:指定 kubeconfig 文件路径,kube-scheduler 使用它连接和验证 kube-apiserver;
  • --leader-elect=true:集群运行模式,启用选举功能;被选为 leader 的节点负责处理工作,其它节点为阻塞状态;

6.04.05 分发systemd unit 文件到所有master 节点;启动检查kube-scheduler 服务

[root@k8s-master01 ~]# vi /opt/k8s/script/scheduler_service.sh

MASTER_IPS=("$1" "$2" "$3")
for master_ip in ${MASTER_IPS[@]};do
        echo ">>> ${master_ip}"
        scp /opt/k8s/kube-scheduler/kube-scheduler.service.template root@${master_ip}:/etc/systemd/system/kube-scheduler.service
        ssh root@${master_ip} "systemctl daemon-reload && systemctl enable kube-scheduler && systemctl start kube-scheduler && systemctl status kube-scheduler|grep Active"
done
[root@k8s-master01 ~]# bash /opt/k8s/script/scheduler_service.sh 192.168.2.201 192.168.2.202 192.168.2.203

6.04.06 查看输出的 metric

  • kube-scheduler 监听 10251 端口,接收 http 请求:
[root@k8s-master01 ~]# ss -nutlp |grep kube-scheduler
tcp    LISTEN   0        128             127.0.0.1:10251          0.0.0.0:*      users:(("kube-scheduler",pid=8584,fd=6))                                       
tcp    LISTEN   0        128                     *:10259                *:*      users:(("kube-scheduler",pid=8584,fd=7))   
                                    
[root@k8s-master01 ~]# curl -s http://127.0.0.1:10251/metrics |head
# HELP apiserver_audit_event_total [ALPHA] Counter of audit events generated and sent to the audit backend.
# TYPE apiserver_audit_event_total counter
apiserver_audit_event_total 0
# HELP apiserver_audit_requests_rejected_total [ALPHA] Counter of apiserver requests rejected due to an error in audit logging backend.
# TYPE apiserver_audit_requests_rejected_total counter
apiserver_audit_requests_rejected_total 0
# HELP apiserver_client_certificate_expiration_seconds [ALPHA] Distribution of the remaining lifetime on the certificate used to authenticate a request.
# TYPE apiserver_client_certificate_expiration_seconds histogram
apiserver_client_certificate_expiration_seconds_bucket{le="0"} 0
apiserver_client_certificate_expiration_seconds_bucket{le="1800"} 0

6.04.07 测试 kube-scheduler 集群的高可用

  • 停掉一个或两个节点的 kube-scheduler 服务,观察其它节点的日志,看是否获取了 leader 权限。
  • 查看当前的 leader
[root@k8s-master02 ~]# kubectl get endpoints kube-scheduler --namespace=kube-system -o yaml

master集群已部署完毕!

posted @ 2019-11-16 14:54  colman_cc  阅读(...)  评论(... 编辑 收藏