一:k8s1.20.x 的重要更新
1、Kubectl debug 设置一个临时容器
2、Sidecar
3、Volume:更改目录权限,fsGroup
4、ConfigMap和Secret
K8S官网:https://kubernetes.io/docs/setup/
最新版高可用安装:https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/high-availability/
二:k8s1.20.x 的安装
2.1 :高可用Kubernetes集群规划
image.png
k8s 的高可用的架构图
image.png!
所有节点配置hosts,修改/etc/hosts如下:
cat /etc/hosts
192.168.100.11 node01.flyfish.cn
192.168.100.12 node02.flyfish.cn
192.168.100.13 node03.flyfish.cn
192.168.100.14 node04.flyfish.cn
192.168.100.15 node05.flyfish.cn
192.168.100.16 node06.flyfish.cn
192.168.100.17 node07.flyfish.cn
192.168.100.18 node08.flyfish.cn
2.2 yum 的更新配置 (所有节点全部安装)
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
cat <
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
sed -i -e ‘/mirrors.cloud.aliyuncs.com/d’ -e ‘/mirrors.aliyuncs.com/d’ /etc/yum.repos.d/CentOS-Base.repo
image.png!
必备工具安装:
yum install wget jq psmisc vim net-tools telnet yum-utils device-mapper-persistent-data lvm2 git -y
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所有节点关闭防火墙、selinux、dnsmasq、swap。服务器配置如下:
systemctl disable --now firewalld
systemctl disable --now dnsmasq
systemctl disable --now NetworkManager
setenforce 0
sed -i ‘s#SELINUX=enforcing#SELINUX=disabled#g’ /etc/sysconfig/selinux
sed -i ‘s#SELINUX=enforcing#SELINUX=disabled#g’ /etc/selinux/config
关闭swap分区 (全部节点)
swapoff -a && sysctl -w vm.swappiness=0
sed -ri ‘/[#]*swap/s@^@#@’ /etc/fstab
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安装ntpdate
rpm -ivh http://mirrors.wlnmp.com/centos/wlnmp-release-centos.noarch.rpm
yum install ntpdate -y
所有节点同步时间。时间同步配置如下:
ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
echo ‘Asia/Shanghai’ >/etc/timezone
ntpdate time2.aliyun.com
加入到crontab
*/5 * * * * ntpdate time2.aliyun.com
所有节点配置limit:
ulimit -SHn 65535
vim /etc/security/limits.conf
末尾添加如下内容
- soft nofile 655360
- hard nofile 131072
- soft nproc 655350
- hard nproc 655350
- soft memlock unlimited
- hard memlock unlimited
安装ntpdate
rpm -ivh http://mirrors.wlnmp.com/centos/wlnmp-release-centos.noarch.rpm
yum install ntpdate -y
所有节点同步时间。时间同步配置如下:
ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
echo ‘Asia/Shanghai’ >/etc/timezone
ntpdate time2.aliyun.com
加入到crontab
*/5 * * * * ntpdate time2.aliyun.com
所有节点配置limit:
ulimit -SHn 65535
vim /etc/security/limits.conf
末尾添加如下内容
- soft nofile 655360
- hard nofile 131072
- soft nproc 655350
- hard nproc 655350
- soft memlock unlimited
- hard memlock unlimited
Master01节点免密钥登录其他节点:
ssh-keygen -t rsa
for i in k8s-master01.flyfish.cn k8s-master02.flyfish.cn k8s-master03.flyfish.cn k8s-node01.flyfish.cn k8s-node02.flyfish.cn;do ssh-copy-id -i .ssh/id_rsa.pub $i;done
所有节点升级系统并重启:
yum update -y && reboot
下载安装源码文件:
cd /root/ ; git clone https://github.com/dotbalo/k8s-ha-install.git
CentOS 7安装yum源如下:
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
cat <
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
sed -i -e ‘/mirrors.cloud.aliyuncs.com/d’ -e ‘/mirrors.aliyuncs.com/d’ /etc/yum.repos.d/CentOS-Base.repo
CentOS 8 安装源如下:
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-8.repo
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
cat <
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
sed -i -e ‘/mirrors.cloud.aliyuncs.com/d’ -e ‘/mirrors.aliyuncs.com/d’ /etc/yum.repos.d/CentOS-Base.repo
所有节点升级系统并重启,此处升级没有升级内核,下节会单独升级内核:
yum install wget jq psmisc vim net-tools telnet yum-utils device-mapper-persistent-data lvm2 -y
yum update -y --exclude=kernel* && reboot #CentOS7需要升级,8不需要
1.1.2 内核配置
CentOS7 需要升级内核至4.18+
https://www.kernel.org/ 和 https://elrepo.org/linux/kernel/el7/x86_64/
CentOS 7 dnf可能无法安装内核
dnf --disablerepo=* --enablerepo=elrepo -y install kernel-ml kernel-ml-devel
grubby --default-kernel
使用如下方式安装最新版内核
rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm
查看最新版内核yum --disablerepo="*" --enablerepo=“elrepo-kernel” list available
[root@k8s-node01 ~]# yum --disablerepo="*" --enablerepo=“elrepo-kernel” list available
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
- elrepo-kernel: mirrors.neusoft.edu.cn
elrepo-kernel | 2.9 kB 00:00:00
elrepo-kernel/primary_db | 1.9 MB 00:00:00
Available Packages
elrepo-release.noarch 7.0-5.el7.elrepo elrepo-kernel
kernel-lt.x86_64 4.4.229-1.el7.elrepo elrepo-kernel
kernel-lt-devel.x86_64 4.4.229-1.el7.elrepo elrepo-kernel
kernel-lt-doc.noarch 4.4.229-1.el7.elrepo elrepo-kernel
kernel-lt-headers.x86_64 4.4.229-1.el7.elrepo elrepo-kernel
kernel-lt-tools.x86_64 4.4.229-1.el7.elrepo elrepo-kernel
kernel-lt-tools-libs.x86_64 4.4.229-1.el7.elrepo elrepo-kernel
kernel-lt-tools-libs-devel.x86_64 4.4.229-1.el7.elrepo elrepo-kernel
kernel-ml.x86_64 5.7.7-1.el7.elrepo elrepo-kernel
kernel-ml-devel.x86_64 5.7.7-1.el7.elrepo elrepo-kernel
kernel-ml-doc.noarch 5.7.7-1.el7.elrepo elrepo-kernel
kernel-ml-headers.x86_64 5.7.7-1.el7.elrepo elrepo-kernel
kernel-ml-tools.x86_64 5.7.7-1.el7.elrepo elrepo-kernel
kernel-ml-tools-libs.x86_64 5.7.7-1.el7.elrepo elrepo-kernel
kernel-ml-tools-libs-devel.x86_64 5.7.7-1.el7.elrepo elrepo-kernel
perf.x86_64 5.7.7-1.el7.elrepo elrepo-kernel
python-perf.x86_64 5.7.7-1.el7.elrepo elrepo-kernel
安装最新版:
yum --enablerepo=elrepo-kernel install kernel-ml kernel-ml-devel –y
安装完成后reboot
更改内核顺序:
grub2-set-default 0 && grub2-mkconfig -o /etc/grub2.cfg && grubby --args=“user_namespace.enable=1” --update-kernel="(grubby --default-kernel)" && reboot
开机后查看内核
[appadmin@k8s-node01 ~] uname -a
Linux k8s-node01 5.7.7-1.el7.elrepo.x86_64 #1 SMP Wed Jul 1 11:53:16 EDT 2020 x86_64 x86_64 x86_64 GNU/Linux
CentOS 8按需升级:
可以采用dnf升级,也可使用上述同样步骤升级(使用上述步骤注意elrepo-release-8.1版本)
rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
dnf install https://www.elrepo.org/elrepo-release-8.1-1.el8.elrepo.noarch.rpm
dnf --disablerepo=* --enablerepo=elrepo -y install kernel-ml kernel-ml-devel
grubby --default-kernel && reboot
安装依赖包:
本所有节点安装ipvsadm:
yum install ipvsadm ipset sysstat conntrack libseccomp -y
所有节点配置ipvs模块,在内核4.19+版本nf_conntrack_ipv4已经改为nf_conntrack,本例安装的内核为4.18,使用nf_conntrack_ipv4即可:
modprobe – ip_vs
modprobe – ip_vs_rr
modprobe – ip_vs_wrr
modprobe – ip_vs_sh
modprobe – nf_conntrack_ipv4
cat /etc/modules-load.d/ipvs.conf
ip_vs
ip_vs_rr
ip_vs_wrr
ip_vs_sh
nf_conntrack_ipv4
ip_tables
ip_set
xt_set
ipt_set
ipt_rpfilter
ipt_REJECT
ipip
然后执行systemctl enable --now systemd-modules-load.service即可
开启一些k8s集群中必须的内核参数,所有节点配置k8s内核:
cat <
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-iptables = 1
fs.may_detach_mounts = 1
vm.overcommit_memory=1
vm.panic_on_oom=0
fs.inotify.max_user_watches=89100
fs.file-max=52706963
fs.nr_open=52706963
net.netfilter.nf_conntrack_max=2310720
net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_keepalive_intvl =15
net.ipv4.tcp_max_tw_buckets = 36000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_max_orphans = 327680
net.ipv4.tcp_orphan_retries = 3
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.ip_conntrack_max = 65536
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_timestamps = 0
net.core.somaxconn = 16384
EOF
sysctl --system
1.1.3 基本组件安装
本节主要安装的是集群中用到的各种组件,比如Docker-ce、Kubernetes各组件等。
查看可用docker-ce版本:
yum list docker-ce.x86_64 --showduplicates | sort -r
[root@k8s-master01 k8s-ha-install]# wget https://download.docker.com/linux/centos/7/x86_64/edge/Packages/containerd.io-1.2.13-3.2.el7.x86_64.rpm
安装 docker-ce 19.03 版本:
yum install -y docker-ce-cli-19.03.8-3.el7.x86_64 docker-ce-19.03.8-3.el7.x86_64
温馨提示:
由于新版kubelet建议使用systemd,所以可以把docker的CgroupDriver改成systemd
cat > /etc/docker/daemon.json <<EOF
{
“exec-opts”: [“native.cgroupdriver=systemd”]
}
EOF
image.png
启动docker
service docker start
chkconfig docker on




