kubeadm安装K8S单master双节点集群

宿主机：
master：172.16.40.97
node1：172.16.40.98
node2：172.16.40.99

# 一、k8s初始化环境：（三台宿主机）

关闭防火墙和selinux

systemctl stop firewalld && systemctl disable firewalld
sed -ri '/^[^#]*SELINUX=/s#=.+$#=disabled#' /etc/selinux/config
setenforce 0

设置时间同步客户端

yum install chrony -y
cat <<EOF > /etc/chrony.conf
server ntp.aliyun.com iburst
stratumweight 0
driftfile /var/lib/chrony/drift
rtcsync
makestep 10 3
bindcmdaddress 127.0.0.1
bindcmdaddress ::1
keyfile /etc/chrony.keys
commandkey 1
generatecommandkey
logchange 0.5
logdir /var/log/chrony
EOF
systemctl restart chronyd && systemctl enable chronyd

各主机之间相互DNS解析和ssh登录

略

升级内核

wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
yum install wget git  jq psmisc -y
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
yum install https://mirrors.aliyun.com/saltstack/yum/redhat/salt-repo-latest-2.el7.noarch.rpm
sed -i "s/repo.saltstack.com/mirrors.aliyun.com\/saltstack/g" /etc/yum.repos.d/salt-latest.repo
yum update -y

更新重启

自选版本

export Kernel_Vsersion=4.18.9-1
wget  http://mirror.rc.usf.edu/compute_lock/elrepo/kernel/el7/x86_64/RPMS/kernel-ml{,-devel}-${Kernel_Vsersion}.el7.elrepo.x86_64.rpm
yum localinstall -y kernel-ml*

查看这个内核里是否有这个内核模块

find /lib/modules -name '*nf_conntrack_ipv4*' -type f

修改内核启动顺序,默认启动的顺序应该为1,升级以后内核是往前面插入,为0（如果每次启动时需要手动选择哪个内核,该步骤可以省略）

grub2-set-default  0 && grub2-mkconfig -o /etc/grub2.cfg

使用下面命令看看确认下是否启动默认内核指向上面安装的内核

grubby --default-kernel

docker官方的内核检查脚本建议(RHEL7/CentOS7: User namespaces disabled; add ‘user_namespace.enable=1’ to boot command line),使用下面命令开启

grubby --args="user_namespace.enable=1" --update-kernel="$(grubby --default-kernel)"

重新加载内核

reboot

需要设定/etc/sysctl.d/k8s.conf的系统参数

cat <<EOF > /etc/sysctl.d/k8s.conf
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 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
EOF
sysctl --system

检查系统内核和模块是否适合运行 docker (仅适用于 linux 系统)

curl https://raw.githubusercontent.com/docker/docker/master/contrib/check-config.sh > check-config.sh
bash ./check-config.sh

安装docker-ce

yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
yum makecache fast
yum install docker-ce-17.06.2.ce -y
sed -i "13i ExecStartPost=/usr/sbin/iptables -P FORWARD ACCEPT" /usr/lib/systemd/system/docker.service
systemctl daemon-reload && systemctl enable docker && systemctl start docker

设置docker开机启动,CentOS安装完成后docker需要手动设置docker命令补全

yum install -y epel-release bash-completion && cp /usr/share/bash-completion/completions/docker /etc/bash_completion.d/
systemctl enable --now docker

在各节点上下载k8s1.13.2版本的对应官方镜像包，网盘地址:  https://pan.baidu.com/s/1NETu4uZrd5ijjXICARNe5A   密码：4oco

#二、安装k8s集群**

三台宿主机进行kubectl kubelet kubeadm安装：

cat <<EOF > /etc/yum.repos.d/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
EOF
yum install -y kubelet kubeadm kubectl
systemctl enable kubelet

master宿主机忽略交换分区未关闭warning：

cat <<EOF > /etc/sysconfig/kubelet
KUBELET_EXTRA_ARGS="--fail-swap-on=false --cgroup-driver=cgroupfs"
EOF

systemctl daemon-reload

master节点进行kubeadm初始化

kubeadm init --kubernetes-version=v1.13.2 --pod-network-cidr=10.244.0.0/16 --service-cidr=10.96.0.0/16 --ignore-preflight-errors=Swap

*[init] Using Kubernetes version: v1.13.2
[preflight] Running pre-flight checks
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using ‘kubeadm config images pull’
[kubelet-start] Writing kubelet environment file with flags to file “/var/lib/kubelet/kubeadm-flags.env”
[kubelet-start] Writing kubelet configuration to file “/var/lib/kubelet/config.yaml”
[kubelet-start] Activating the kubelet service
[certs] Using certificateDir folder “/etc/kubernetes/pki”
[certs] Generating “ca” certificate and key
[certs] Generating “apiserver-kubelet-client” certificate and key
[certs] Generating “apiserver” certificate and key
[certs] apiserver serving cert is signed for DNS names [master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 172.16.40.97]
[certs] Generating “front-proxy-ca” certificate and key
[certs] Generating “front-proxy-client” certificate and key
[certs] Generating “etcd/ca” certificate and key
[certs] Generating “etcd/server” certificate and key
[certs] etcd/server serving cert is signed for DNS names [master localhost] and IPs [172.16.40.97 127.0.0.1 ::1]
[certs] Generating “etcd/peer” certificate and key
[certs] etcd/peer serving cert is signed for DNS names [master localhost] and IPs [172.16.40.97 127.0.0.1 ::1]
[certs] Generating “etcd/healthcheck-client” certificate and key
[certs] Generating “apiserver-etcd-client” certificate and key
[certs] Generating “sa” key and public key
[kubeconfig] Using kubeconfig folder “/etc/kubernetes”
[kubeconfig] Writing “admin.conf” kubeconfig file
[kubeconfig] Writing “kubelet.conf” kubeconfig file
[kubeconfig] Writing “controller-manager.conf” kubeconfig file
[kubeconfig] Writing “scheduler.conf” kubeconfig file
[control-plane] Using manifest folder “/etc/kubernetes/manifests”
[control-plane] Creating static Pod manifest for “kube-apiserver”
[control-plane] Creating static Pod manifest for “kube-controller-manager”
[control-plane] Creating static Pod manifest for “kube-scheduler”
[etcd] Creating static Pod manifest for local etcd in “/etc/kubernetes/manifests”
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory “/etc/kubernetes/manifests”. This can take up to 4m0s
[apiclient] All control plane components are healthy after 20.003620 seconds
[uploadconfig] storing the configuration used in ConfigMap “kubeadm-config” in the “kube-system” Namespace
[kubelet] Creating a ConfigMap “kubelet-config-1.13” in namespace kube-system with the configuration for the kubelets in the cluster
[patchnode] Uploading the CRI Socket information “/var/run/dockershim.sock” to the Node API object “master” as an annotation
[mark-control-plane] Marking the node master as control-plane by adding the label “node-role.kubernetes.io/master=’’”
[mark-control-plane] Marking the node master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: 2s9xxt.8lgyw6yzt21qq8xf
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstraptoken] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstraptoken] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstraptoken] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstraptoken] creating the “cluster-info” ConfigMap in the “kube-public” namespace
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy

Your Kubernetes master has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

You should now deploy a pod network to the cluster.
Run “kubectl apply -f [podnetwork].yaml” with one of the options listed at:
https://kubernetes.io/docs/concepts/cluster-administration/addons/

You can now join any number of machines by running the following on each node
as root:

kubeadm join 172.16.40.97:6443 –token 2s9xxt.8lgyw6yzt21qq8xf –discovery-token-ca-cert-hash sha256:c141fb0608b4b83136272598d2623589d73546762abc987391479e8e049b0d76*

master节点用kubectl访问集群

mkdir -p $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config

master节点拉取github配置文件

git clone https://github.com/sky-daiji/k8s-install.git

接下来我们来安装flannel网络插件

cd /root/k8s-install
kubectl apply -f kube-flannel/

master节点查看集群状态

[root@master ~]# kubectl get cs
NAME                 STATUS    MESSAGE              ERROR
controller-manager   Healthy   ok
scheduler            Healthy   ok
etcd-0               Healthy   {"health": "true"}

添加各节点进去集群

kubeadm join 172.16.40.97:6443 --token 2s9xxt.8lgyw6yzt21qq8xf --discovery-token-ca-cert-hash sha256:c141fb0608b4b83136272598d2623589d73546762abc987391479e8e049b0d76

查看节点是否都添加到集群里

[root@master ~]# kubectl get node
NAME     STATUS   ROLES    AGE   VERSION
master   Ready    master   15m   v1.13.2
node1    Ready    <none>   13m   v1.13.2
node2    Ready    <none>   13m   v1.13.2

查看k8s各自组件运行情况

在所有节点启用ipvs模块

yum install -y ipvsadm
vim /etc/sysconfig/modules/ipvs.modules
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4

chmod +x /etc/sysconfig/modules/ipvs.modules

source /etc/sysconfig/modules/ipvs.modules

lsmod | grep -e ip_vs -enf_conntrack_ipv4

kubectl edit cm kube-proxy -n kube-system  将mode修改为ipvs

kubectl get pod -n kube-system | grep kube-proxy | awk '{system("kubectl delete pod"$1" -n kube-system")}'  批量删除并重建kube-proxy

　　

安装kuber-dashboard插件

cd /root/k8s-install
kubectl apply -f  kubernetes-dashboard/

查看kubernetes-dashboard插件安装是否成功

kubectl get pod -n kube-system  |grep kubernetes-dashboard

访问Dashboard

https://172.16.40.97:30091
选择Token令牌模式登录。

kubectl describe secret/$(kubectl get secret -n kube-system |grep admin|awk '{print $1}') -n kube-system

在master节点上安装heapster，从v1.11.0开始，性能采集不再采用heapster采集pod性能数据，而是使用metrics-server，但是dashboard依然使用heapster呈现性能数据

cd /root/k8s-install
kubectl apply -f heapster/

安装metrics-server

cd /root/k8s-install
kubectl apply -f metrics-server/

# 等待5分钟，查看性能数据是否正常收集
[root@master01 ~]# kubectl top pods -n kube-system
NAME                                                                CPU(cores)                                           MEMORY(bytes)
coredns-86c58d9df4-n5brl                                            2m                                                      15Mi
coredns-86c58d9df4-rhl5d                                            2m                                                      20Mi
etcd-master01                                                       14m                                                     97Mi
heapster-c8847db7d-rw845                                            1m                                                      40Mi
kube-apiserver-master01                                             21m                                                     553Mi
kube-controller-manager-master01                                    23m                                                     95Mi
kube-flannel-ds-amd64-bh5dm                                         2m                                                      11Mi
kube-flannel-ds-amd64-bzfnm                                         2m                                                      17Mi
kube-flannel-ds-amd64-clrmd                                         2m                                                      14Mi
kube-proxy-cgcqj                                                    3m                                                      21Mi
kube-proxy-lrzh7                                                    3m                                                      24Mi
kube-proxy-wkgjq                                                    3m                                                      18Mi
kube-scheduler-master01                                             6m                                                      20Mi
kubernetes-dashboard-57df4db6b-tzvcc                                1m                                                      22Mi
metrics-server-9d78d4d64-zjv4z                                      1m                                                      28Mi
monitoring-grafana-b4c79dbd4-bzk9r                                  1m                                                      29Mi
monitoring-influxdb-576db68c87-57sg7                                1m                                                      74Mi

　　

安装prometheus

cd /root/k8s-install
kubectl apply -f prometheus/

成功安装后访问以下网址打开prometheus管理界面，查看相关性能采集数据: http://172.16.40.97:30013/

成功安装后访问以下网址打开grafana管理界面(账号密码都是admin)，查看相关性能采集数据: http://172.16.40.97:30006登录后，进入datasource设置界面，增加prometheus数据源，

进入导入dashboard界面: http://172.16.40.97:30006/dashboard/import 导入heapster/grafana-dashboard目录下的dashboard Kubernetes App Metrics和Kubernetes cluster monitoring (via Prometheus)

如果你觉得这份文档对你有帮助，请支付宝扫描下方的二维码进行捐赠，谢谢！