centos7使用kubeadm安装kubernetes 1.11版本多主高可用
centosdockerkubeadmkubernetes
老杨的博客
kubernetes 介绍 要学习一个新的东西，先了解它是什么，熟悉基本概念会有很大帮助。以下是我学习时看过的一篇核心概念介绍。 http://dockone.io/article/932
搭建 Kubernetes 集群环境有以下 3 种方式：
minikube Minikube 是一个工具，可以在本地快速运行一个单点的 Kubernetes，尝试 Kubernetes 或日常开发的用户使用。不能用于生产环境。 官方地址：https://kubernetes.io/docs/setup/minikube/
以下是符合企业生产环境标准的 Kubernetes 集群环境方式：
kubeadm Kubeadm 也是一个工具，提供kubeadm init和kubeadm join，用于快速部署 Kubernetes 集群。
官方地址：https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm/
二进制包 从官方下载发行版的二进制包，手动部署每个组件，组成 Kubernetes 集群。
官方也提供了一个互动测试环境供大家玩耍：https://kubernetes.io/cn/docs/tutorials/kubernetes-basics/cluster-interactive/ 国外的这个最多支持 5 个节点的测试环境也很赞：https://labs.play-with-k8s.com/
lab1: etcd master haproxy keepalived 192.168.105.92
lab2: etcd master haproxy keepalived 192.168.105.93
lab3: etcd master haproxy keepalived 192.168.105.94
lab4: node 192.168.105.95
lab4: node 192.168.105.96
vip(loadblancer ip): 192.168.105.99
virtualbox 实验使用的 Vagrantfile：
# -*- mode: ruby -*-
# vi: set ft=ruby :
ENV["LC_ALL"] = "en_US.UTF-8"
Vagrant.configure("2") do |config|
(2..6).each do |i|
config.vm.define "lab#{i}" do |node|
node.vm.box = "centos-7.4-docker-17"
node.ssh.insert_key = false
node.vm.hostname = "lab#{i}"
node.vm.network "private_network", ip: "192.168.105.9#{i}"
node.vm.provision "shell",
inline: "echo hello from node #{i}"
node.vm.provider "virtualbox" do |v|
v.cpus = 2
v.customize ["modifyvm", :id, "--name", "lab#{i}", "--memory", "2048"]
end
end
end
end
使用阿里 yum 源，并将默认 yum 源文件都移走。
cd /etc/yum.repos.d
mkdir bak
mv *.repo bak/
vim CentOS-Base.repo
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-$releasever - Base - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/
http://mirrors.aliyuncs.com/centos/$releasever/os/$basearch/
http://mirrors.cloud.aliyuncs.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-$releasever - Updates - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/
http://mirrors.aliyuncs.com/centos/$releasever/updates/$basearch/
http://mirrors.cloud.aliyuncs.com/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
http://mirrors.aliyuncs.com/centos/$releasever/extras/$basearch/
http://mirrors.cloud.aliyuncs.com/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/
http://mirrors.aliyuncs.com/centos/$releasever/centosplus/$basearch/
http://mirrors.cloud.aliyuncs.com/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/contrib/$basearch/
http://mirrors.aliyuncs.com/centos/$releasever/contrib/$basearch/
http://mirrors.cloud.aliyuncs.com/centos/$releasever/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
vim epel-7.repo
[epel]
name=Extra Packages for Enterprise Linux 7 - $basearch
baseurl=http://mirrors.aliyun.com/epel/7/$basearch
failovermethod=priority
enabled=1
gpgcheck=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
[epel-debuginfo]
name=Extra Packages for Enterprise Linux 7 - $basearch - Debug
baseurl=http://mirrors.aliyun.com/epel/7/$basearch/debug
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
gpgcheck=0
[epel-source]
name=Extra Packages for Enterprise Linux 7 - $basearch - Source
baseurl=http://mirrors.aliyun.com/epel/7/SRPMS
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
gpgcheck=0
vim docker-ce.repo
[docker-ce-stable]
name=Docker CE Stable - $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/$basearch/stable
enabled=1
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
[docker-ce-stable-debuginfo]
name=Docker CE Stable - Debuginfo $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/debug-$basearch/stable
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
[docker-ce-stable-source]
name=Docker CE Stable - Sources
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/source/stable
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
[docker-ce-edge]
name=Docker CE Edge - $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/$basearch/edge
enabled=1
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
[docker-ce-edge-debuginfo]
name=Docker CE Edge - Debuginfo $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/debug-$basearch/edge
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
[docker-ce-edge-source]
name=Docker CE Edge - Sources
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/source/edge
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
[docker-ce-test]
name=Docker CE Test - $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/$basearch/test
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
[docker-ce-test-debuginfo]
name=Docker CE Test - Debuginfo $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/debug-$basearch/test
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
[docker-ce-test-source]
name=Docker CE Test - Sources
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/source/test
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
[docker-ce-nightly]
name=Docker CE Nightly - $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/$basearch/nightly
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
[docker-ce-nightly-debuginfo]
name=Docker CE Nightly - Debuginfo $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/debug-$basearch/nightly
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
[docker-ce-nightly-source]
name=Docker CE Nightly - Sources
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/source/nightly
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
vim kubernetes.repo
[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
v1.11.1 版本推荐使用 docker v17.03,v1.11,v1.12,v1.13, 也可以使用，再高版本的 docker 可能无法正常使用。
这里安装 v1.13 版本。
yum -y install docker
systemctl enable docker && systemctl restart docker
docker 启动错误解决：
Error starting daemon: SELinux is not supported with the overlay2 graph driver on this kernel. Either boot into a newer kernel or disable selinux in docke...-enabled=false)
修改/etc/sysconfig/docker中的--selinux-enabled=false
如下操作在所有节点操作
yum install -y kubelet kubeadm kubectl ipvsadm
systemctl enable kubelet && systemctl start kubelet
如下操作在所有节点操作
# 设置时区
ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
# 临时禁用selinux
# 永久关闭 修改/etc/sysconfig/selinux文件设置
sed -i 's/SELINUX=.*/SELINUX=disabled/' /etc/sysconfig/selinux
setenforce 0 # 需要重启生效
# 开启forward
# Docker从1.13版本开始调整了默认的防火墙规则
# 禁用了iptables filter表中FOWARD链
# 这样会引起Kubernetes集群中跨Node的Pod无法通信
iptables -P FORWARD ACCEPT
# 临时关闭swap
# 永久关闭 注释/etc/fstab文件里swap相关的行
swapoff -a
# 开启防火墙允许集群机器间通信（为了方便测试或者直接关闭防火墙）
firewall-cmd --add-rich-rule 'rule family=ipv4 source address=192.168.105.0/24 accept' # # 指定源IP（段），即时生效
firewall-cmd --add-rich-rule 'rule family=ipv4 source address=192.168.105.0/24 accept' --permanent # 指定源IP（段），永久生效
# 配置转发相关参数，否则可能会出错
cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
vm.swappiness=0
EOF
sysctl --system
# 加载ipvs相关内核模块
# 如果重新开机，需要重新加载
modprobe ip_vs
modprobe ip_vs_rr
modprobe ip_vs_wrr
modprobe ip_vs_sh
modprobe nf_conntrack_ipv4
lsmod | grep ip_vs
如下操作在所有节点操作
cat >>/etc/hosts<<EOF
192.168.105.92 lab1
192.168.105.93 lab2
192.168.105.94 lab3
192.168.105.95 lab4
192.168.105.96 lab5
EOF
如下操作在节点 lab1,lab2,lab3 操作
# 拉取haproxy镜像
docker pull haproxy:1.7.8-alpine
mkdir /etc/haproxy
cat >/etc/haproxy/haproxy.cfg<<EOF
global
log 127.0.0.1 local0 err
maxconn 50000
uid 99
gid 99
#daemon
nbproc 1
pidfile haproxy.pid
defaults
mode http
log 127.0.0.1 local0 err
maxconn 50000
retries 3
timeout connect 5s
timeout client 30s
timeout server 30s
timeout check 2s
listen admin_stats
mode http
bind 0.0.0.0:1080
log 127.0.0.1 local0 err
stats refresh 30s
stats uri /haproxy-status
stats realm Haproxy\ Statistics
stats auth will:will
stats hide-version
stats admin if TRUE
frontend k8s-https
bind 0.0.0.0:8443
mode tcp
#maxconn 50000
default_backend k8s-https
backend k8s-https
mode tcp
balance roundrobin
server lab1 192.168.105.92:6443 weight 1 maxconn 1000 check inter 2000 rise 2 fall 3
server lab2 192.168.105.93:6443 weight 1 maxconn 1000 check inter 2000 rise 2 fall 3
server lab3 192.168.105.94:6443 weight 1 maxconn 1000 check inter 2000 rise 2 fall 3
EOF
# 启动haproxy
docker run -d --name my-haproxy \
-v /etc/haproxy:/usr/local/etc/haproxy:ro \
-p 8443:8443 \
-p 1080:1080 \
--restart always \
haproxy:1.7.8-alpine
# 查看日志
docker logs my-haproxy
# 浏览器查看状态
http://192.168.105.92:1080/haproxy-status
http://192.168.105.93:1080/haproxy-status
http://192.168.105.94:1080/haproxy-status
# 拉取keepalived镜像
docker pull osixia/keepalived:1.4.4
# 启动
# 载入内核相关模块
lsmod | grep ip_vs
modprobe ip_vs
# 启动keepalived
# ens32为本次实验192.168.105.0/24网段的所在网卡
docker run --net=host --cap-add=NET_ADMIN \
-e KEEPALIVED_INTERFACE=ens32 \
-e KEEPALIVED_VIRTUAL_IPS="#PYTHON2BASH:['192.168.105.99']" \
-e KEEPALIVED_UNICAST_PEERS="#PYTHON2BASH:['192.168.105.92','192.168.105.93','192.168.105.94']" \
-e KEEPALIVED_PASSWORD=hello \
--name k8s-keepalived \
--restart always \
-d osixia/keepalived:1.4.4
# 查看日志
# 会看到两个成为backup 一个成为master
docker logs k8s-keepalived
# 此时会配置 192.168.105.99 到其中一台机器
# ping测试
ping -c4 192.168.105.99
# 如果失败后清理后，重新实验
#docker rm -f k8s-keepalived
#ip a del 192.168.105.99/32 dev ens32
如下操作在所有节点操作
# 配置kubelet使用国内pause镜像
# 配置kubelet的cgroups
# 获取docker的cgroups
DOCKER_CGROUPS=$(docker info | grep 'Cgroup' | cut -d' ' -f3)
echo $DOCKER_CGROUPS
cat >/etc/sysconfig/kubelet<<EOF
KUBELET_EXTRA_ARGS="--cgroup-driver=$DOCKER_CGROUPS --pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.1"
EOF
# 启动
systemctl daemon-reload
systemctl enable kubelet && systemctl restart kubelet
如下操作在 lab1 节点操作
# centos下使用 ipvs 模式问题已解决
# 参考 https://github.com/kubernetes/kubernetes/issues/65461
cd /etc/kubernetes
# 生成配置文件
CP0_IP="192.168.105.92"
CP0_HOSTNAME="lab1"
cat >kubeadm-master.config<<EOF
apiVersion: kubeadm.k8s.io/v1alpha2
kind: MasterConfiguration
kubernetesVersion: v1.11.1
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
apiServerCertSANs:
- "lab1"
- "lab2"
- "lab3"
- "192.168.105.92"
- "192.168.105.93"
- "192.168.105.94"
- "192.168.105.99"
- "127.0.0.1"
api:
advertiseAddress: $CP0_IP
controlPlaneEndpoint: 192.168.105.99:8443
etcd:
local:
extraArgs:
listen-client-urls: "https://127.0.0.1:2379,https://$CP0_IP:2379"
advertise-client-urls: "https://$CP0_IP:2379"
listen-peer-urls: "https://$CP0_IP:2380"
initial-advertise-peer-urls: "https://$CP0_IP:2380"
initial-cluster: "$CP0_HOSTNAME=https://$CP0_IP:2380"
serverCertSANs:
- $CP0_HOSTNAME
- $CP0_IP
peerCertSANs:
- $CP0_HOSTNAME
- $CP0_IP
controllerManagerExtraArgs:
node-monitor-grace-period: 10s
pod-eviction-timeout: 10s
networking:
podSubnet: 10.244.0.0/16
kubeProxy:
config:
mode: ipvs
# mode: iptables
EOF
# 提前拉取镜像
# 如果执行失败 可以多次执行
kubeadm config images pull --config kubeadm-master.config
# 初始化
# 注意保存返回的 join 命令
kubeadm init --config kubeadm-master.config
# 初始化失败时使用
#kubeadm reset
# 将ca相关文件传至其他master节点
USER=root # customizable
CONTROL_PLANE_IPS=(lab2 lab3)
for host in ${CONTROL_PLANE_IPS[@]}; do
scp /etc/kubernetes/pki/ca.crt "${USER}"@$host:/etc/kubernetes/pki/ca.crt
scp /etc/kubernetes/pki/ca.key "${USER}"@$host:/etc/kubernetes/pki/ca.key
scp /etc/kubernetes/pki/sa.key "${USER}"@$host:/etc/kubernetes/pki/sa.key
scp /etc/kubernetes/pki/sa.pub "${USER}"@$host:/etc/kubernetes/pki/sa.pub
scp /etc/kubernetes/pki/front-proxy-ca.crt "${USER}"@$host:/etc/kubernetes/pki/front-proxy-ca.crt
scp /etc/kubernetes/pki/front-proxy-ca.key "${USER}"@$host:/etc/kubernetes/pki/front-proxy-ca.key
ssh "${USER}"@$host "mkdir -p /etc/kubernetes/pki/etcd"
scp /etc/kubernetes/pki/etcd/ca.crt "${USER}"@$host:/etc/kubernetes/pki/etcd/ca.crt
scp /etc/kubernetes/pki/etcd/ca.key "${USER}"@$host:/etc/kubernetes/pki/etcd/ca.key
scp /etc/kubernetes/admin.conf "${USER}"@$host:/etc/kubernetes/admin.conf
done
kubeadm init失败解决： 将阿里云 image tag 成官方的 image，即可解决init失败问题。(v1.11.0 有此问题)
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver-amd64:v1.11.1 k8s.gcr.io/kube-apiserver-amd64:v1.11.1
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy-amd64:v1.11.1 k8s.gcr.io/kube-proxy-amd64:v1.11.1
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/etcd-amd64:3.2.18 k8s.gcr.io/etcd-amd64:3.2.18
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler-amd64:v1.11.1 k8s.gcr.io/kube-scheduler-amd64:v1.11.1
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager-amd64:v1.11.1 k8s.gcr.io/kube-controller-manager-amd64:v1.11.1
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.1.3 k8s.gcr.io/coredns:1.1.3
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.1 k8s.gcr.io/pause-amd64:3.1
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1 k8s.gcr.io/pause:3.1
docker images # 结果如下
docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
k8s.gcr.io/kube-apiserver-amd64 v1.11.1 214c48e87f58 3 weeks ago 187 MB
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver-amd64 v1.11.1 214c48e87f58 3 weeks ago 187 MB
k8s.gcr.io/kube-proxy-amd64 v1.11.1 1d3d7afd77d1 3 weeks ago 97.8 MB
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy-amd64 v1.11.1 1d3d7afd77d1 3 weeks ago 97.8 MB
k8s.gcr.io/kube-controller-manager-amd64 v1.11.1 55b70b420785 3 weeks ago 155 MB
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager-amd64 v1.11.1 55b70b420785 3 weeks ago 155 MB
k8s.gcr.io/kube-scheduler-amd64 v1.11.1 0e4a34a3b0e6 3 weeks ago 56.8 MB
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler-amd64 v1.11.1 0e4a34a3b0e6 3 weeks ago 56.8 MB
k8s.gcr.io/coredns 1.1.3 b3b94275d97c 2 months ago 45.6 MB
registry.cn-hangzhou.aliyuncs.com/google_containers/coredns 1.1.3 b3b94275d97c 2 months ago 45.6 MB
docker.io/osixia/keepalived 1.4.4 d83816204582 2 months ago 53.7 MB
registry.cn-shanghai.aliyuncs.com/gcr-k8s/flannel v0.10.0-amd64 b949a39093d6 2 months ago 44.6 MB
k8s.gcr.io/etcd-amd64 3.2.18 b8df3b177be2 3 months ago 219 MB
registry.cn-hangzhou.aliyuncs.com/google_containers/etcd-amd64 3.2.18 b8df3b177be2 3 months ago 219 MB
quay.io/coreos/flannel v0.10.0-amd64 f0fad859c909 6 months ago 44.6 MB
k8s.gcr.io/pause-amd64 3.1 da86e6ba6ca1 7 months ago 742 kB
k8s.gcr.io/pause 3.1 da86e6ba6ca1 7 months ago 742 kB
registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64 3.1 da86e6ba6ca1 7 months ago 742 kB
registry.cn-hangzhou.aliyuncs.com/google_containers/pause 3.1 da86e6ba6ca1 7 months ago 742 kB
docker.io/haproxy 1.7.8-alpine 297a495c0e70 12 months ago 14.7 MB
如下操作在 lab2 节点操作
# centos下使用 ipvs 模式问题已解决
# 参考 https://github.com/kubernetes/kubernetes/issues/65461
cd /etc/kubernetes
# 生成配置文件
CP0_IP="192.168.105.92"
CP0_HOSTNAME="lab1"
CP1_IP="192.168.105.93"
CP1_HOSTNAME="lab2"
cat >kubeadm-master.config<<EOF
apiVersion: kubeadm.k8s.io/v1alpha2
kind: MasterConfiguration
kubernetesVersion: v1.11.1
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
apiServerCertSANs:
- "lab1"
- "lab2"
- "lab3"
- "192.168.105.92"
- "192.168.105.93"
- "192.168.105.94"
- "192.168.105.99"
- "127.0.0.1"
api:
advertiseAddress: $CP1_IP
controlPlaneEndpoint: 192.168.105.99:8443
etcd:
local:
extraArgs:
listen-client-urls: "https://127.0.0.1:2379,https://$CP1_IP:2379"
advertise-client-urls: "https://$CP1_IP:2379"
listen-peer-urls: "https://$CP1_IP:2380"
initial-advertise-peer-urls: "https://$CP1_IP:2380"
initial-cluster: "$CP0_HOSTNAME=https://$CP0_IP:2380,$CP1_HOSTNAME=https://$CP1_IP:2380"
initial-cluster-state: existing
serverCertSANs:
- $CP1_HOSTNAME
- $CP1_IP
peerCertSANs:
- $CP1_HOSTNAME
- $CP1_IP
controllerManagerExtraArgs:
node-monitor-grace-period: 10s
pod-eviction-timeout: 10s
networking:
podSubnet: 10.244.0.0/16
kubeProxy:
config:
mode: ipvs
# mode: iptables
EOF
# 配置kubelet
kubeadm alpha phase certs all --config kubeadm-master.config
kubeadm alpha phase kubelet config write-to-disk --config kubeadm-master.config
kubeadm alpha phase kubelet write-env-file --config kubeadm-master.config
kubeadm alpha phase kubeconfig kubelet --config kubeadm-master.config
systemctl restart kubelet
# 添加etcd到集群中
CP0_IP="192.168.105.92"
CP0_HOSTNAME="lab1"
CP1_IP="192.168.105.93"
CP1_HOSTNAME="lab2"
export KUBECONFIG=/etc/kubernetes/admin.conf
kubectl exec -n kube-system etcd-${CP0_HOSTNAME} -- etcdctl --ca-file /etc/kubernetes/pki/etcd/ca.crt --cert-file /etc/kubernetes/pki/etcd/peer.crt --key-file /etc/kubernetes/pki/etcd/peer.key --endpoints=https://${CP0_IP}:2379 member add ${CP1_HOSTNAME} https://${CP1_IP}:2380
kubeadm alpha phase etcd local --config kubeadm-master.config
# 提前拉取镜像
# 如果执行失败 可以多次执行
kubeadm config images pull --config kubeadm-master.config
# 部署
kubeadm alpha phase kubeconfig all --config kubeadm-master.config
kubeadm alpha phase controlplane all --config kubeadm-master.config
kubeadm alpha phase mark-master --config kubeadm-master.config
如下操作在 lab3 节点操作
# centos下使用 ipvs 模式问题已解决
# 参考 https://github.com/kubernetes/kubernetes/issues/65461
cd /etc/kubernetes
# 生成配置文件
CP0_IP="192.168.105.92"
CP0_HOSTNAME="lab1"
CP1_IP="192.168.105.93"
CP1_HOSTNAME="lab2"
CP2_IP="192.168.105.94"
CP2_HOSTNAME="lab3"
cat >kubeadm-master.config<<EOF
apiVersion: kubeadm.k8s.io/v1alpha2
kind: MasterConfiguration
kubernetesVersion: v1.11.1
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
apiServerCertSANs:
- "lab1"
- "lab2"
- "lab3"
- "192.168.105.92"
- "192.168.105.93"
- "192.168.105.94"
- "192.168.105.99"
- "127.0.0.1"
api:
advertiseAddress: $CP2_IP
controlPlaneEndpoint: 192.168.105.99:8443
etcd:
local:
extraArgs:
listen-client-urls: "https://127.0.0.1:2379,https://$CP2_IP:2379"
advertise-client-urls: "https://$CP2_IP:2379"
listen-peer-urls: "https://$CP2_IP:2380"
initial-advertise-peer-urls: "https://$CP2_IP:2380"
initial-cluster: "$CP0_HOSTNAME=https://$CP0_IP:2380,$CP1_HOSTNAME=https://$CP1_IP:2380,$CP2_HOSTNAME=https://$CP2_IP:2380"
initial-cluster-state: existing
serverCertSANs:
- $CP2_HOSTNAME
- $CP2_IP
peerCertSANs:
- $CP2_HOSTNAME
- $CP2_IP
controllerManagerExtraArgs:
node-monitor-grace-period: 10s
pod-eviction-timeout: 10s
networking:
podSubnet: 10.244.0.0/16
kubeProxy:
config:
mode: ipvs
# mode: iptables
EOF
# 配置kubelet
kubeadm alpha phase certs all --config kubeadm-master.config
kubeadm alpha phase kubelet config write-to-disk --config kubeadm-master.config
kubeadm alpha phase kubelet write-env-file --config kubeadm-master.config
kubeadm alpha phase kubeconfig kubelet --config kubeadm-master.config
systemctl restart kubelet
# 添加etcd到集群中
CP0_IP="192.168.105.92"
CP0_HOSTNAME="lab1"
CP2_IP="192.168.105.94"
CP2_HOSTNAME="lab3"
KUBECONFIG=/etc/kubernetes/admin.conf
kubectl exec -n kube-system etcd-${CP0_HOSTNAME} -- etcdctl --ca-file /etc/kubernetes/pki/etcd/ca.crt --cert-file /etc/kubernetes/pki/etcd/peer.crt --key-file /etc/kubernetes/pki/etcd/peer.key --endpoints=https://${CP0_IP}:2379 member add ${CP2_HOSTNAME} https://${CP2_IP}:2380
kubeadm alpha phase etcd local --config kubeadm-master.config
# 提前拉取镜像
# 如果执行失败 可以多次执行
kubeadm config images pull --config kubeadm-master.config
# 部署
kubeadm alpha phase kubeconfig all --config kubeadm-master.config
kubeadm alpha phase controlplane all --config kubeadm-master.config
kubeadm alpha phase mark-master --config kubeadm-master.config
如下操作在任意 master 节点操作
rm -rf $HOME/.kube
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
# 查看node节点
kubectl get nodes
# 只有网络插件也安装配置完成之后，才能会显示为ready状态
# 设置master允许部署应用pod，参与工作负载，现在可以部署其他系统组件
# 如 dashboard, heapster, efk等
kubectl taint nodes --all node-role.kubernetes.io/master-
如下操作在任意 master 节点操作
# 下载配置
cd /etc/kubernetes
mkdir flannel && cd flannel
wget https://raw.githubusercontent.com/coreos/flannel/v0.10.0/Documentation/kube-flannel.yml
# 修改配置
# 此处的ip配置要与上面kubeadm的pod-network一致
net-conf.json: |
{
"Network": "10.244.0.0/16",
"Backend": {
"Type": "vxlan"
}
}
# 修改镜像
image: registry.cn-shanghai.aliyuncs.com/gcr-k8s/flannel:v0.10.0-amd64
# 如果Node有多个网卡的话，参考flannel issues 39701，
# https://github.com/kubernetes/kubernetes/issues/39701
# 目前需要在kube-flannel.yml中使用--iface参数指定集群主机内网网卡的名称，
# 否则可能会出现dns无法解析。容器无法通信的情况，需要将kube-flannel.yml下载到本地，
# flanneld启动参数加上--iface=<iface-name>
containers:
- name: kube-flannel
image: registry.cn-shanghai.aliyuncs.com/gcr-k8s/flannel:v0.10.0-amd64
command:
- /opt/bin/flanneld
args:
- --ip-masq
- --kube-subnet-mgr
- --iface=ens32
# 启动
kubectl apply -f kube-flannel.yml
# 查看
kubectl get pods --namespace kube-system
kubectl get svc --namespace kube-system
如下操作在所有 node 节点操作
# 此命令为初始化master成功后返回的结果
kubeadm join 192.168.105.99:8443 --token j6zjtl.tgptijigkhhnuc23 --discovery-token-ca-cert-hash sha256:f3e9ae0841084185649b6c111b7e992465b81f2442d42871c6a15731a17dabba
node 节点报错处理办法：
tail -f /var/log/message
Jul 26 07:52:21 localhost kubelet: E0726 07:52:21.336281 10018 summary.go:102] Failed to get system container stats for "/system.slice/kubelet.service": failed to get cgroup stats for "/system.slice/kubelet.service": failed to get container info for "/system.slice/kubelet.service": unknown container "/system.slice/kubelet.service"
在 kubelet 配置文件追加以下配置 /etc/sysconfig/kubelet
# Append configuration in Kubelet
--runtime-cgroups=/systemd/system.slice --kubelet-cgroups=/systemd/system.slice
默认是没 web 界面的，可以在 master 机器上安装一个 dashboard 插件，实现通过 web 来管理。
如下操作在任意 master 节点操作
cd /etc/kubernetes
wget https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/recommended/kubernetes-dashboard.yaml # 下载
编辑kubernetes-dashboard.yaml文件`：
- name: kubernetes-dashboard
image: registry.cn-hangzhou.aliyuncs.com/google_containers/kubernetes-dashboard-amd64:v1.8.3
执行命令
# 安装Dashboard插件
kubectl create -f kubernetes-dashboard.yaml
kubectl get svc,pod --all-namespaces | grep dashboard
可以看到 kubernetes-dashboard 已正常运行。
kube-system service/kubernetes-dashboard NodePort 10.108.96.71 <none> 443:30356/TCP 1m
kube-system pod/kubernetes-dashboard-754f4d5f69-nfvrk 0/1 CrashLoopBackOff 3 1m
需要一个管理集群 admin 的权限，新建kubernetes-dashboard-admin.rbac.yaml文件，内容如下
apiVersion: v1
kind: ServiceAccount
metadata:
name: admin-user
namespace: kube-system
---
# Create ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: admin-user
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: cluster-admin
subjects:
- kind: ServiceAccount
name: admin-user
namespace: kube-system
执行命令
kubectl create -f kubernetes-dashboard-admin.rbac.yaml
找到 kubernete-dashboard-admin 的 token，用户登录使用
执行命令并查看结果
[root@lab1 kubernetes]# kubectl -n kube-system get secret | grep admin-user
admin-user-token-b9mpt kubernetes.io/service-account-token 3 29s
可以看到名称是 kubernetes-dashboard-admin-token-ddskx，使用该名称执行如下命令
[root@lab1 kubernetes]# kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | grep admin-user | awk '{print $1}')
Name: admin-user-token-b9mpt
Namespace: kube-system
Labels: <none>
Annotations: kubernetes.io/service-account.name=admin-user
kubernetes.io/service-account.uid=f1247ca8-9173-11e8-bbc3-000c29ea3e30
Type: kubernetes.io/service-account-token
Data
====
token: eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi11c2VyLXRva2VuLWI5bXB0Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9zZXJ2aWNlLWFjY291bnQubmFtZSI6ImFkbWluLXVzZXIiLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlcnZpY2UtYWNjb3VudC51aWQiOiJmMTI0N2NhOC05MTczLTExZTgtYmJjMy0wMDBjMjllYTNlMzAiLCJzdWIiOiJzeXN0ZW06c2VydmljZWFjY291bnQ6a3ViZS1zeXN0ZW06YWRtaW4tdXNlciJ9.g9F6vn84ds6iVi1TJViWaK1oHMsY0vQoV5Xq8n0nF5WF4uJkkToHxs0nHO4G4u927ZWsMuF0JiTD4rKB0uJcnHdc4GwBN6L2XMceD69YCpunLlgoFOFbu6z9IsZfyvHvFAYbm0Tv4JWBYxkCqmeTKtL1GOtobIs24dvfXk6inn51ZhTAUW_urWvIn8yqckOBJkq7B_wf6EZA0QeNEhhbt_GHPpwq0CMhk4cWHXh_a27y-qKkpu5Cbo_Ux2kUA44o1wmiHgbw4Lh-__KJY3LZmIu9PZzyWyIPaUWlSQ76GXHyOZQ8dw3WRANi9zaEpiwi4e4XXXXXXXXXXXXXXXXXXXXXXX
ca.crt: 1025 bytes
namespace: 11 bytes
记下这串 token，等下登录使用，这个 token 默认是永久的。
此处推荐 API Server 方式访问。（谷歌内核浏览器）
kubectl proxy方式访问如下操作在 lab1 上操作
kubectl proxy --address=0.0.0.0 --disable-filter=true
即可通过浏览器访问: http://192.168.105.92:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/#!/login
注意 仪表盘使用 kubectl 代理命令不应暴露公开,因为它只允许 HTTP 连接。域以外的 localhost 和 127.0.0.1 将不能登录。在登录页面点击登录按钮什么都不会发生后，跳过登录后，没有任何权限。
此方式只允许开发测试使用。为了便于开发测试，以下配置用于提升默认权限为超级用户权限。
vim kubernetes-dashboard-test.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
name: kubernetes-dashboard
namespace: kube-system
---
# Create ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: kubernetes-dashboard
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: cluster-admin
subjects:
- kind: ServiceAccount
name: kubernetes-dashboard
namespace: kube-system
这种访问方式仪表板只建议在单个节点上设置开发环境。
编辑kubernetes-dashboard.yaml文件，添加type: NodePort和nodePort: 30001，暴露 Dashboard 服务为 30001 端口，参考如下。
# ------------------- Dashboard Service ------------------- #
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kube-system
spec:
type: NodePort # NodePort登录方式
ports:
- port: 443
targetPort: 8443
nodePort: 30001 # NodePort登录暴露端口
selector:
k8s-app: kubernetes-dashboard
注意 仪表盘可以在 master 节点上访问，如果是多节点集群，官方文档说应该是使用节点 IP 和 NodePort 来访问，但是经过测试，
https://<master-ip>:<nodePort>和https://<node-ip>:<nodePort>都可以访问。
https://<master-ip>:<apiserver-port>/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/
注意 这种方式访问仪表盘的仅仅可能在安装了你的用户证书的浏览器上。与 API Server 通信可以使用示例所使用的证书 kubeconfig 文件。
浏览器访问问题：
{
"kind": "Status",
"apiVersion": "v1",
"metadata": {
},
"status": "Failure",
"message": "services \"https:kubernetes-dashboard:\" is forbidden: User \"system:anonymous\" cannot get services/proxy in the namespace \"kube-system\"",
"reason": "Forbidden",
"details": {
"name": "https:kubernetes-dashboard:",
"kind": "services"
},
"code": 403
}
这是因为最新版的 k8s 默认启用了 RBAC，并为未认证用户赋予了一个默认的身份：anonymous。
对于 API Server 来说，它是使用证书进行认证的，我们需要先创建一个证书：
/etc/kubernetes/admin.conf，在 上文 中，我们已经复制到了$HOME/.kube/config中。# 生成client-certificate-data
grep 'client-certificate-data' ~/.kube/config | head -n 1 | awk '{print $2}' | base64 -d >> kubecfg.crt
# 生成client-key-data
grep 'client-key-data' ~/.kube/config | head -n 1 | awk '{print $2}' | base64 -d >> kubecfg.key
# 生成p12
openssl pkcs12 -export -clcerts -inkey kubecfg.key -in kubecfg.crt -out kubecfg.p12 -name "kubernetes-client"
注意 对于生产系统，我们应该为每个用户应该生成自己的证书，因为不同的用户会有不同的命名空间访问权限。
可以动态的更新 Nginx 配置等，是比较灵活，更为推荐的暴露服务的方式，但也相对比较复杂，业务环境推荐使用。
测试容器间的通信和 DNS 配置好网络之后，kubeadm 会自动部署 coredns
如下测试可以在配置 kubectl 的节点上操作
# 启动名为nginx的容器
kubectl run nginx --replicas=2 --image=nginx:alpine --port=80
# 暴露nginx容器为服务（--type=NodePort/ClusterIP/LoadBalancer，3种类型访问方式不同）
kubectl expose deployment nginx --type=NodePort --name=example-service-nodeport
kubectl expose deployment nginx --name=example-service
# 查看状态
kubectl get deploy
kubectl get pods
kubectl get svc
kubectl describe svc example-service
# DNS解析
kubectl run curl --image=radial/busyboxplus:curl -i --tty
nslookup kubernetes
nslookup example-service
curl example-service
# 访问测试
# 10.103.184.0 为查看svc时获取到的clusterip
curl "10.103.184.0:80"
# 32223 为查看svc时获取到的 nodeport
http://192.168.105.93:32223/
http://192.168.105.94:32223/
# 清理删除
kubectl delete svc example-service example-service-nodeport
kubectl delete deploy nginx curl
# 高可用测试
# 关闭任一master节点测试集群是能否正常执行上一步的基础测试，查看相关信息，不能同时关闭两个节点，因为3个节点组成的etcd集群，最多只能有一个当机。
# 查看组件状态
kubectl get pod --all-namespaces -o wide
kubectl get pod --all-namespaces -o wide | grep lab1
kubectl get pod --all-namespaces -o wide | grep lab2
kubectl get pod --all-namespaces -o wide | grep lab3
kubectl get nodes -o wide
kubectl get deploy
kubectl get pods
kubectl get svc
# 访问测试
CURL_POD=$(kubectl get pods | grep curl | grep Running | cut -d ' ' -f1)
kubectl exec -it $CURL_POD -- sh --tty
nslookup kubernetes
nslookup example-service
curl example-service
忘记初始 master 节点时的 node 节点加入集群命令怎么办
# 简单方法
kubeadm token create --print-join-command
# 第二种方法
token=$(kubeadm token generate)
kubeadm token create $token --print-join-command --ttl=0
# 查看集群结点状态
kubectl get nodes
# 查看详细结点信息
kubectl describe nodes
# 查看所有pod
kubectl get pods --all-namespaces
# 查看集群服务状态
kubectl get svc --all-namespaces
# 查看集群运行在那些ip上
kubectl cluster-info
# 查看master的各种token
kubectl get secret -n kube-system
# 查看某一个特定的token
kubectl describe secret/[token name] -n kube-system
参考文档： [1] https://kubernetes.io/docs/setup/independent/install-kubeadm/ [2] https://kubernetes.io/docs/setup/independent/create-cluster-kubeadm/ [3] https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm-init/ [4] https://kubernetes.io/docs/setup/independent/high-availability/ [5] https://sealyun.com/post/k8s-ipvs/ [6] http://www.maogx.win/posts/33/ [7] https://github.com/opsnull/follow-me-install-kubernetes-cluster [8] https://github.com/xizhibei/blog/issues/64 [9] https://www.cnblogs.com/RainingNight/p/deploying-k8s-dashboard-ui.html
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