谷粒商城-官方笔记-分布式集群(4/4)
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个人笔记(新手级细节教程)：
https://blog.csdn.net/hancoder/article/details/106922139
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官方笔记-基础篇：https://blog.csdn.net/hancoder/article/details/107612619
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官方笔记-高级篇：https://blog.csdn.net/hancoder/article/details/107612746
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官方笔记-集群篇：https://blog.csdn.net/hancoder/article/details/107612802
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官方笔记下载地址：https://download.csdn.net/download/hancoder/12665396
文章目录
- 1、K8s快速入门
- 1）简介
- 2）架构
- （1）整体主从方式
- （2）master节点架构
- （3）Node节点架构
- 3）概念
- 4）快速体验
- （1）安装minikube
- （2）体验nginx部署升级
- 2、K8s集群安装
- 1）kubeadm
- 2）前置要求
- 3）部署步骤
- 4）环境准备
- （1）准备工作
- （2）启动三个虚拟机
- （3）设置Linux环境（三个节点都执行）
- 5）所有节点安装docker、kubeadm、kubelet、kubectl
- （1）安装Docker
- （2）添加阿里与Yum源
- （3）安装kubeadm，kubelet和kubectl
- 6）部署k8s-master
- （1）master节点初始化
- （2）测试Kubectl（主节点执行）
- 7）安装POD网络插件（CNI）
- 8）加入kubenetes的Node节点
- 9）入门操作kubernetes集群
- 3、K8s细节
- 1、kubectl文档
- 2、资源类型
- 3、格式化输出
- 语法
- 示例
- 命令参考
- service的意义
- Ingress
- 安装kubernetes可视化界面——DashBoard
- kubesphere
- 1、简洁
- 2、安装前提提交
- 1、安装helm（master节点执行）
- 2、安装Tilller（Master执行）
1、K8s快速入门
1）简介
kubernetes简称k8s。是用于自动部署，扩展和管理容器化应用程序的开源系统。
中文官网：https://kubernetes.io/Zh/
中文社区：https://www.kubernetes.org.cn/
官方文档：https://kubernetes.io/zh/docs/home/
社区文档：https://docs.kubernetes.org.cn/
部署方式的进化：
2）架构
（1）整体主从方式
（2）master节点架构
（3）Node节点架构
3）概念
4）快速体验
（1）安装minikube
https://github.com/kubernetes/minikube/releases
下载minikuber-windows-amd64.exe 改名为minikube.exe
打开virtualBox，打开cmd
运行
minikube start --vm-driver=virtualbox --registry-mirror=https://registry.docker-cn.com
等待20分钟即可。
（2）体验nginx部署升级
-
提交一个nginx deployment
kubectl apply -f https://k8s.io/examples/application/deployment.yaml -
升级 nginx deployment
kubectl apply -f https://k8s.io/examples/application/deployment-update.yaml -
扩容 nginx deployment
2、K8s集群安装
1）kubeadm
kubeadm是官方社区推出的一个用于快速部署kuberneters集群的工具。
这个工具能通过两条指令完成一个kuberneters集群的部署
创建一个master节点
$ kuberneters init
将一个node节点加入到当前集群中
$ kubeadm join
2）前置要求
一台或多台机器，操作系统Centos7.x-86_x64
硬件配置：2GB或更多RAM，2个CPU或更多CPU，硬盘30GB或更多
集群中所有的机器之间网络互通
可以访问外网，需要拉取镜像
禁止Swap分区
3）部署步骤
- 在所有的节点上安装Docker和kubeadm
- 不是Kubernetes Master
- 部署容器网络插件
- 部署Kubernetes Node，将节点加入Kubernetes集群中
- 部署DashBoard web页面，可视化查看Kubernetes资源
4）环境准备
（1）准备工作
- 我们可以使用vagrant快速创建三个虚拟机。虚拟机启动前先设置virtualbox的主机网络。现在全部统一为192.168.56.1，以后所有虚拟机都是56.x的ip地址。
- 在全局设定中，找到一个空间比较大的磁盘用用来存放镜像。
（2）启动三个虚拟机
- 使用我们提供的vagrant文件，复制到非中文无空格目录下，运行vagrant up启动三个虚拟机。其实vagrant完全可以一键部署全部K8s集群
https://github.com/rootsongjc/kubernetes-vagrant-centos-cluster
http://github.com/davidkbainbridge/k8s-playground
下面是vagrantfile，使用它来创建三个虚拟机，分别为k8s-node1，k8s-node2和k8s-node3.
Vagrant.configure("2") do |config|
(1..3).each do |i|
config.vm.define "k8s-node#{i}" do |node|
# 设置虚拟机的Box
node.vm.box = "centos/7"
# 设置虚拟机的主机名
node.vm.hostname="k8s-node#{i}"
# 设置虚拟机的IP
node.vm.network "private_network", ip: "192.168.56.#{99+i}", netmask: "255.255.255.0"
# 设置主机与虚拟机的共享目录
# node.vm.synced_folder "~/Documents/vagrant/share", "/home/vagrant/share"
# VirtaulBox相关配置
node.vm.provider "virtualbox" do |v|
# 设置虚拟机的名称
v.name = "k8s-node#{i}"
# 设置虚拟机的内存大小
v.memory = 4096
# 设置虚拟机的CPU个数
v.cpus = 4
end
end
end
end
- 进入到三个虚拟机，开启root的密码访问权限
Vagrant ssh xxx进入到系统后
su root 密码为vagrant
vi /etc/ssh/sshd_config
修改
PermitRootLogin yes
PasswordAuthentication yes
所有的虚拟机设为4核4G
关于在"网络地址转换"的连接方式下，三个节点的eth0，IP地址相同的问题。
**问题描述：**查看k8s-node1的路由表：
[root@k8s-node1 ~]# ip route show
default via 10.0.2.2 dev eth0 proto dhcp metric 100
10.0.2.0/24 dev eth0 proto kernel scope link src 10.0.2.15 metric 100
192.168.56.0/24 dev eth1 proto kernel scope link src 192.168.56.100 metric 101
[root@k8s-node1 ~
能够看到路由表中记录的是，通过端口eth0进行数据包的收发。
分别查看k8s-node1，k8s-node2和k8s-node3的eth0所绑定的IP地址，发现它们都是相同的，全都是10.0.2.15，这些地址是供kubernetes集群通信用的，区别于eth1上的IP地址，是通远程管理使用的。
[root@k8s-node1 ~]# ip addr
...
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 52:54:00:8a:fe:e6 brd ff:ff:ff:ff:ff:ff
inet 10.0.2.15/24 brd 10.0.2.255 scope global noprefixroute dynamic eth0
valid_lft 84418sec preferred_lft 84418sec
inet6 fe80::5054:ff:fe8a:fee6/64 scope link
valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 08:00:27:a3:ca:c0 brd ff:ff:ff:ff:ff:ff
inet 192.168.56.100/24 brd 192.168.56.255 scope global noprefixroute eth1
valid_lft forever preferred_lft forever
inet6 fe80::a00:27ff:fea3:cac0/64 scope link
valid_lft forever preferred_lft forever
[root@k8s-node1 ~]#
**原因分析：**这是因为它们使用是端口转发规则，使用同一个地址，通过不同的端口来区分。但是这种端口转发规则在以后的使用中会产生很多不必要的问题，所以需要修改为NAT网络类型。
解决方法：
- 选择三个节点，然后执行“管理”->“全局设定”->“网络”，添加一个NAT网络。
- 分别修改每台设备的网络类型，并刷新重新生成MAC地址。
- 再次查看三个节点的IP
（3）设置Linux环境（三个节点都执行）
- 关闭防火墙
systemctl stop firewalld
systemctl disable firewalld
- 关闭Linux
sed -i 's/enforcing/disabled/' /etc/selinux/config
setenforce 0
- 关闭swap
swapoff -a #临时关闭
sed -ri 's/.*swap.*/#&/' /etc/fstab #永久关闭
free -g #验证，swap必须为0
- 添加主机名与IP对应关系：
查看主机名：
hostname
如果主机名不正确，可以通过“hostnamectl set-hostname
vi /etc/hosts
10.0.2.15 k8s-node1
10.0.2.4 k8s-node2
10.0.2.5 k8s-node3
将桥接的IPV4流量传递到iptables的链：
cat > /etc/sysctl.d/k8s.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
应用规则：
sysctl --system
疑难问题：遇见提示是只读的文件系统，运行如下命令
mount -o remount rw /
- date 查看时间（可选）
yum -y install ntpupdate
ntpupdate time.window.com #同步最新时间
5）所有节点安装docker、kubeadm、kubelet、kubectl
Kubenetes默认CRI（容器运行时）为Docker，因此先安装Docker。
（1）安装Docker
1、卸载之前的docker
$ sudo yum remove docker \
docker-client \
docker-client-latest \
docker-common \
docker-latest \
docker-latest-logrotate \
docker-logrotate \
docker-engine
2、安装Docker -CE
$ sudo yum install -y yum-utils
$ sudo yum-config-manager \
--add-repo \
https://download.docker.com/linux/centos/docker-ce.repo
$ sudo yum -y install docker-ce docker-ce-cli containerd.io
3、配置镜像加速
sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
"registry-mirrors": ["https://ke9h1pt4.mirror.aliyuncs.com"]
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker
4、启动Docker && 设置docker开机启动
systemctl enable docker
基础环境准备好，可以给三个虚拟机备份一下；
（2）添加阿里与Yum源
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
更多详情见： https://developer.aliyun.com/mirror/kubernetes
（3）安装kubeadm，kubelet和kubectl
yum list|grep kube
安装
yum install -y kubelet-1.17.3 kubeadm-1.17.3 kubectl-1.17.3
开机启动
systemctl enable kubelet && systemctl start kubelet
查看kubelet的状态：
systemctl status kubelet
查看kubelet版本：
[root@k8s-node2 ~]# kubelet --version
Kubernetes v1.17.3
6）部署k8s-master
（1）master节点初始化
在Master节点上，创建并执行master_images.sh
#!/bin/bash
images=(
kube-apiserver:v1.17.3
kube-proxy:v1.17.3
kube-controller-manager:v1.17.3
kube-scheduler:v1.17.3
coredns:1.6.5
etcd:3.4.3-0
pause:3.1
)
for imageName in ${images[@]} ; do
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName
# docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName k8s.gcr.io/$imageName
done
初始化kubeadm
$ kubeadm init \
--apiserver-advertise-address=10.0.2.15 \
--image-repository registry.cn-hangzhou.aliyuncs.com/google_containers \
--kubernetes-version v1.17.3 \
--service-cidr=10.96.0.0/16 \
--pod-network-cidr=10.244.0.0/16
注：
- –apiserver-advertise-address=10.0.2.21 ：这里的IP地址是master主机的地址，为上面的eth0网卡的地址；
执行结果：
[root@k8s-node1 opt]# kubeadm init \
> --apiserver-advertise-address=10.0.2.15 \
> --image-repository registry.cn-hangzhou.aliyuncs.com/google_containers \
> --kubernetes-version v1.17.3 \
> --service-cidr=10.96.0.0/16 \
> --pod-network-cidr=10.244.0.0/16
W0503 14:07:12.594252 10124 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
[init] Using Kubernetes version: v1.17.3
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[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] Starting the kubelet
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [k8s-node1 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.0.2.15]
[certs] Generating "apiserver-kubelet-client" certificate and key
[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 [k8s-node1 localhost] and IPs [10.0.2.15 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8s-node1 localhost] and IPs [10.0.2.15 127.0.0.1 ::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"
W0503 14:07:30.908642 10124 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[control-plane] Creating static Pod manifest for "kube-scheduler"
W0503 14:07:30.911330 10124 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[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 22.506521 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.18" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node k8s-node1 as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node k8s-node1 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: sg47f3.4asffoi6ijb8ljhq
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy
#表示kubernetes已经初始化成功了
Your Kubernetes control-plane 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/
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join 10.0.2.15:6443 --token sg47f3.4asffoi6ijb8ljhq \
--discovery-token-ca-cert-hash sha256:81fccdd29970cbc1b7dc7f171ac0234d53825bdf9b05428fc9e6767436991bfb
[root@k8s-node1 opt]#
由于默认拉取镜像地址k8s.cr.io国内无法访问，这里指定阿里云仓库地址。可以手动按照我们的images.sh先拉取镜像。
地址变为：registry.aliyuncs.com/googole_containers也可以。
科普：无类别域间路由（Classless Inter-Domain Routing 、CIDR）是一个用于给用户分配IP地址以及在互联网上有效第路由IP数据包的对IP地址进行归类的方法。
拉取可能失败，需要下载镜像。
运行完成提前复制：加入集群的令牌。
（2）测试Kubectl（主节点执行）
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
详细部署文档：https://kubernetes.io/docs/concepts/cluster-administration/addons/
$ kubectl get nodes #获取所有节点
目前Master状态为notready。等待网络加入完成即可。
$ journalctl -u kubelet #查看kubelet日志
kubeadm join 10.0.2.15:6443 --token sg47f3.4asffoi6ijb8ljhq \
--discovery-token-ca-cert-hash sha256:81fccdd29970cbc1b7dc7f171ac0234d53825bdf9b05428fc9e6767436991bfb
7）安装POD网络插件（CNI）
在master节点上执行按照POD网络插件
kubectl apply -f \
https://raw.githubusercontent.com/coreos/flanne/master/Documentation/kube-flannel.yml
以上地址可能被墙，可以直接获取本地已经下载的flannel.yml运行即可，如：
[root@k8s-node1 k8s]# kubectl apply -f kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds-amd64 created
daemonset.apps/kube-flannel-ds-arm64 created
daemonset.apps/kube-flannel-ds-arm created
daemonset.apps/kube-flannel-ds-ppc64le created
daemonset.apps/kube-flannel-ds-s390x created
[root@k8s-node1 k8s]#
同时flannel.yml中指定的images访问不到可以去docker hub找一个wget yml地址
vi 修改yml 所有amd64的地址修改了即可
等待大约3分钟
kubectl get pods -n kube-system 查看指定名称空间的pods
kubectl get pods -all-namespace 查看所有名称空间的pods
$ ip link set cni0 down 如果网络出现问题，关闭cni0，重启虚拟机继续测试
执行watch kubectl get pod -n kube-system -o wide 监控pod进度
等待3-10分钟，完全都是running以后继续
查看命名空间：
[root@k8s-node1 k8s]# kubectl get ns
NAME STATUS AGE
default Active 30m
kube-node-lease Active 30m
kube-public Active 30m
kube-system Active 30m
[root@k8s-node1 k8s]#
[root@k8s-node1 k8s]# kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-546565776c-9sbmk 0/1 Pending 0 31m
kube-system coredns-546565776c-t68mr 0/1 Pending 0 31m
kube-system etcd-k8s-node1 1/1 Running 0 31m
kube-system kube-apiserver-k8s-node1 1/1 Running 0 31m
kube-system kube-controller-manager-k8s-node1 1/1 Running 0 31m
kube-system kube-flannel-ds-amd64-6xwth 1/1 Running 0 2m50s
kube-system kube-proxy-sz2vz 1/1 Running 0 31m
kube-system kube-scheduler-k8s-node1 1/1 Running 0 31m
[root@k8s-node1 k8s]#
查看master上的节点信息：
[root@k8s-node1 k8s]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-node1 Ready master 34m v1.17.3 #status为ready才能够执行下面的命令
[root@k8s-node1 k8s]#
最后再次执行，并且分别在“k8s-node2”和“k8s-node3”上也执行这里命令：
kubeadm join 10.0.2.15:6443 --token sg47f3.4asffoi6ijb8ljhq \
--discovery-token-ca-cert-hash sha256:81fccdd29970cbc1b7dc7f171ac0234d53825bdf9b05428fc9e6767436991bfb
[root@k8s-node1 opt]# kubectl get nodes;
NAME STATUS ROLES AGE VERSION
k8s-node1 Ready master 47m v1.17.3
k8s-node2 NotReady <none> 75s v1.17.3
k8s-node3 NotReady <none> 76s v1.17.3
[root@k8s-node1 opt]#
监控pod进度
watch kubectl get pod -n kube-system -o wide
等到所有的status都变为running状态后，再次查看节点信息：
[root@k8s-node1 ~]# kubectl get nodes;
NAME STATUS ROLES AGE VERSION
k8s-node1 Ready master 3h50m v1.17.3
k8s-node2 Ready <none> 3h3m v1.17.3
k8s-node3 Ready <none> 3h3m v1.17.3
[root@k8s-node1 ~]#
8）加入kubenetes的Node节点
在node节点中执行，向集群中添加新的节点，执行在kubeadm init 输出的kubeadm join命令；
确保node节点成功：
token过期怎么办
kubeadm token create --print-join-command
9）入门操作kubernetes集群
1、在主节点上部署一个tomcat
kubectl create deployment tomcat6 --image=tomcat:6.0.53-jre8
获取所有的资源：
[root@k8s-node1 k8s]# kubectl get all
NAME READY STATUS RESTARTS AGE
pod/tomcat6-7b84fb5fdc-cfd8g 0/1 ContainerCreating 0 41s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 70m
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/tomcat6 0/1 1 0 41s
NAME DESIRED CURRENT READY AGE
replicaset.apps/tomcat6-7b84fb5fdc 1 1 0 41s
[root@k8s-node1 k8s]#
kubectl get pods -o wide 可以获取到tomcat部署信息，能够看到它被部署到了k8s-node2上了
[root@k8s-node1 k8s]# kubectl get all -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod/tomcat6-7b84fb5fdc-cfd8g 1/1 Running 0 114s 10.244.2.2 k8s-node2 <none> <none>
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 71m <none>
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
deployment.apps/tomcat6 1/1 1 1 114s tomcat tomcat:6.0.53-jre8 app=tomcat6
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
replicaset.apps/tomcat6-7b84fb5fdc 1 1 1 114s tomcat tomcat:6.0.53-jre8 app=tomcat6,pod-template-hash=7b84fb5fdc
[root@k8s-node1 k8s]#
查看node2节点上，下载了哪些镜像：
[root@k8s-node2 opt]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy v1.17.3 0d40868643c6 2 weeks ago 117MB
registry.cn-hangzhou.aliyuncs.com/google_containers/pause 3.2 80d28bedfe5d 2 months ago 683kB
quay.io/coreos/flannel v0.11.0-amd64 ff281650a721 15 months ago 52.6MB
tomcat 6.0.53-jre8 49ab0583115a 2 years ago 290MB
[root@k8s-node2 opt]#
查看Node2节点上，正在运行的容器：
[root@k8s-node2 opt]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
9194cc4f0b7a tomcat "catalina.sh run" 2 minutes ago Up 2 minutes k8s_tomcat_tomcat6-7b84fb5fdc-cfd8g_default_0c9ebba2-992d-4c0e-99ef-3c4c3294bc59_0
f44af0c7c345 registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.2 "/pause" 3 minutes ago Up 3 minutes k8s_POD_tomcat6-7b84fb5fdc-cfd8g_default_0c9ebba2-992d-4c0e-99ef-3c4c3294bc59_0
ef74c90491e4 ff281650a721 "/opt/bin/flanneld -…" 20 minutes ago Up 20 minutes k8s_kube-flannel_kube-flannel-ds-amd64-5xs5j_kube-system_11a94346-316d-470b-9668-c15ce183abec_0
c8a524e5a193 registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy "/usr/local/bin/kube…" 25 minutes ago Up 25 minutes k8s_kube-proxy_kube-proxy-mvlnk_kube-system_519de79a-e8d8-4b1c-a74e-94634cebabce_0
4590685c519a registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.2 "/pause" 26 minutes ago Up 26 minutes k8s_POD_kube-flannel-ds-amd64-5xs5j_kube-system_11a94346-316d-470b-9668-c15ce183abec_0
54e00af5cde4 registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.2 "/pause" 26 minutes ago Up 26 minutes k8s_POD_kube-proxy-mvlnk_kube-system_519de79a-e8d8-4b1c-a74e-94634cebabce_0
[root@k8s-node2 opt]#
在node1上执行：
[root@k8s-node1 k8s]# kubectl get pods
NAME READY STATUS RESTARTS AGE
tomcat6-7b84fb5fdc-cfd8g 1/1 Running 0 5m35s
[root@k8s-node1 k8s]# kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
default tomcat6-7b84fb5fdc-cfd8g 1/1 Running 0 163m
kube-system coredns-546565776c-9sbmk 1/1 Running 0 3h52m
kube-system coredns-546565776c-t68mr 1/1 Running 0 3h52m
kube-system etcd-k8s-node1 1/1 Running 0 3h52m
kube-system kube-apiserver-k8s-node1 1/1 Running 0 3h52m
kube-system kube-controller-manager-k8s-node1 1/1 Running 0 3h52m
kube-system kube-flannel-ds-amd64-5xs5j 1/1 Running 0 3h6m
kube-system kube-flannel-ds-amd64-6xwth 1/1 Running 0 3h24m
kube-system kube-flannel-ds-amd64-fvnvx 1/1 Running 0 3h6m
kube-system kube-proxy-7tkvl 1/1 Running 0 3h6m
kube-system kube-proxy-mvlnk 1/1 Running 0 3h6m
kube-system kube-proxy-sz2vz 1/1 Running 0 3h52m
kube-system kube-scheduler-k8s-node1 1/1 Running 0 3h52m
[root@k8s-node1 ~]#
从前面看到tomcat部署在Node2上，现在模拟因为各种原因宕机的情况，将node2关闭电源，观察情况。
[root@k8s-node1 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-node1 Ready master 4h4m v1.17.3
k8s-node2 NotReady <none> 3h18m v1.17.3
k8s-node3 Ready <none> 3h18m v1.17.3
[root@k8s-node1 ~]#
[root@k8s-node1 ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
tomcat6-7b84fb5fdc-cfd8g 1/1 Running 0 177m 10.244.2.2 k8s-node2 <none> <none>
[root@k8s-node1 ~]#
2、暴露nginx访问
在master上执行
kubectl expose deployment tomcat6 --port=80 --target-port=8080 --type=NodePort
pod的80映射容器的8080；server会带来pod的80
查看服务：
[root@k8s-node1 ~]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 12h
tomcat6 NodePort 10.96.24.191 <none> 80:30526/TCP 49s
[root@k8s-node1 ~]#
[root@k8s-node1 ~]# kubectl get svc -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 12h <none>
tomcat6 NodePort 10.96.24.191 <none> 80:30526/TCP 3m30s app=tomcat6
[root@k8s-node1 ~]#
http://192.168.56.100:30526/
[root@k8s-node1 ~]# kubectl get all
NAME READY STATUS RESTARTS AGE
pod/tomcat6-7b84fb5fdc-qt5jm 1/1 Running 0 13m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 12h
service/tomcat6 NodePort 10.96.24.191 <none> 80:30526/TCP 9m50s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/tomcat6 1/1 1 1 11h
NAME DESIRED CURRENT READY AGE
replicaset.apps/tomcat6-7b84fb5fdc 1 1 1 11h
[root@k8s-node1 ~]#
3、动态扩容测试
kubectl get deployment
[root@k8s-node1 ~]# kubectl get deployment
NAME READY UP-TO-DATE AVAILABLE AGE
tomcat6 2/2 2 2 11h
[root@k8s-node1 ~]#
应用升级： kubectl set image (–help查看帮助)
扩容：kubectl scale --replicas=3 deployment tomcat6
[root@k8s-node1 ~]# kubectl scale --replicas=3 deployment tomcat6
deployment.apps/tomcat6 scaled
[root@k8s-node1 ~]#
[root@k8s-node1 ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
tomcat6-7b84fb5fdc-hdgmc 1/1 Running 0 61s 10.244.2.5 k8s-node2 <none> <none>
tomcat6-7b84fb5fdc-qt5jm 1/1 Running 0 19m 10.244.1.2 k8s-node3 <none> <none>
tomcat6-7b84fb5fdc-vlrh6 1/1 Running 0 61s 10.244.2.4 k8s-node2 <none> <none>
[root@k8s-node1 ~]# kubectl get svc -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 13h <none>
tomcat6 NodePort 10.96.24.191 <none> 80:30526/TCP 16m app=tomcat6
[root@k8s-node1 ~]#
扩容了多份，所有无论访问哪个node的指定端口，都可以访问到tomcat6
http://192.168.56.101:30526/
http://192.168.56.102:30526/
缩容：kubectl scale --replicas=2 deployment tomcat6
[root@k8s-node1 ~]# kubectl scale --replicas=2 deployment tomcat6
deployment.apps/tomcat6 scaled
[root@k8s-node1 ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
tomcat6-7b84fb5fdc-hdgmc 0/1 Terminating 0 4m47s k8s-node2
tomcat6-7b84fb5fdc-qt5jm 1/1 Running 0 22m 10.244.1.2 k8s-node3
tomcat6-7b84fb5fdc-vlrh6 1/1 Running 0 4m47s 10.244.2.4 k8s-node2
[root@k8s-node1 ~]#
4、以上操作的yaml获取
参照k8s细节
5、删除
kubectl get all
#查看所有资源
[root@k8s-node1 ~]# kubectl get all
NAME READY STATUS RESTARTS AGE
pod/tomcat6-7b84fb5fdc-qt5jm 1/1 Running 0 26m
pod/tomcat6-7b84fb5fdc-vlrh6 1/1 Running 0 8m16s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 13h
service/tomcat6 NodePort 10.96.24.191 <none> 80:30526/TCP 22m
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/tomcat6 2/2 2 2 11h
NAME DESIRED CURRENT READY AGE
replicaset.apps/tomcat6-7b84fb5fdc 2 2 2 11h
[root@k8s-node1 ~]#
#删除deployment.apps/tomcat6
[root@k8s-node1 ~]# kubectl delete deployment.apps/tomcat6
deployment.apps "tomcat6" deleted
#查看剩余的资源
[root@k8s-node1 ~]# kubectl get all
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 13h
service/tomcat6 NodePort 10.96.24.191 <none> 80:30526/TCP 30m
[root@k8s-node1 ~]#
[root@k8s-node1 ~]#
#删除service/tomcat6
[root@k8s-node1 ~]# kubectl delete service/tomcat6
service "tomcat6" deleted
[root@k8s-node1 ~]# kubectl get all
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 13h
[root@k8s-node1 ~]#
kubectl delete deploye/nginx
kubectl delete service/nginx-service
3、K8s细节
1、kubectl文档
https://kubernetes.io/zh/docs/reference/kubectl/overview/
2、资源类型
https://kubernetes.io/zh/docs/reference/kubectl/overview/#%e8%b5%84%e6%ba%90%e7%b1%bb%e5%9e%8b
3、格式化输出
https://kubernetes.io/zh/docs/reference/kubectl/overview/
所有
kubectl命令的默认输出格式都是人类可读的纯文本格式。要以特定格式向终端窗口输出详细信息，可以将-o或--output参数添加到受支持的kubectl命令中。语法
kubectl [command] [TYPE] [NAME] -o=<output_format>根据
kubectl操作，支持以下输出格式：
Output format Description -o custom-columns=使用逗号分隔的自定义列列表打印表。 -o custom-columns-file=使用 `` 文件中的自定义列模板打印表。 -o json输出 JSON 格式的 API 对象 `-o jsonpath= 打印 jsonpath 表达式定义的字段 -o jsonpath-file=打印 `` 文件中 jsonpath 表达式定义的字段。 -o name仅打印资源名称而不打印任何其他内容。 -o wide以纯文本格式输出，包含任何附加信息。对于 pod 包含节点名。 -o yaml输出 YAML 格式的 API 对象。 示例
在此示例中，以下命令将单个 pod 的详细信息输出为 YAML 格式的对象：
kubectl get pod web-pod-13je7 -o yaml请记住：有关每个命令支持哪种输出格式的详细信息，请参阅 kubectl 参考文档。
–dry-run：
–dry-run=‘none’: Must be “none”, “server”, or “client”. If client strategy, only print the object that would be
sent, without sending it. If server strategy, submit server-side request without persisting the resource.
值必须为none，server或client。如果是客户端策略，则只打印该发送对象，但不发送它。如果服务器策略，提交服务器端请求而不持久化资源。
也就是说，通过–dry-run选项，并不会真正的执行这条命令。
[root@k8s-node1 ~]# kubectl create deployment tomcat6 --image=tomcat:6.0.53-jre8 --dry-run -o yaml
W0504 03:39:08.389369 8107 helpers.go:535] --dry-run is deprecated and can be replaced with --dry-run=client.
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: tomcat6
name: tomcat6
spec:
replicas: 1
selector:
matchLabels:
app: tomcat6
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: tomcat6
spec:
containers:
- image: tomcat:6.0.53-jre8
name: tomcat
resources: {}
status: {}
[root@k8s-node1 ~]#
实际上我们也可以将这个yaml输出到文件，然后使用kubectl apply -f来应用它
#输出到tomcat6.yaml
[root@k8s-node1 ~]# kubectl create deployment tomcat6 --image=tomcat:6.0.53-jre8 --dry-run -o yaml >tomcat6.yaml
W0504 03:46:18.180366 11151 helpers.go:535] --dry-run is deprecated and can be replaced with --dry-run=client.
#修改副本数为3
[root@k8s-node1 ~]# cat tomcat6.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: tomcat6
name: tomcat6
spec:
replicas: 3 #修改副本数为3
selector:
matchLabels:
app: tomcat6
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: tomcat6
spec:
containers:
- image: tomcat:6.0.53-jre8
name: tomcat
resources: {}
status: {}
#应用tomcat6.yaml
[root@k8s-node1 ~]# kubectl apply -f tomcat6.yaml
deployment.apps/tomcat6 created
[root@k8s-node1 ~]#
查看pods：
[root@k8s-node1 ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
tomcat6-7b84fb5fdc-5jh6t 1/1 Running 0 8s
tomcat6-7b84fb5fdc-8lhwv 1/1 Running 0 8s
tomcat6-7b84fb5fdc-j4qmh 1/1 Running 0 8s
[root@k8s-node1 ~]#
查看某个pod的具体信息：
[root@k8s-node1 ~]# kubectl get pods tomcat6-7b84fb5fdc-5jh6t -o yaml
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: "2020-05-04T03:50:47Z"
generateName: tomcat6-7b84fb5fdc-
labels:
app: tomcat6
pod-template-hash: 7b84fb5fdc
managedFields:
- apiVersion: v1
fieldsType: FieldsV1
fieldsV1:
f:metadata:
f:generateName: {}
f:labels:
.: {}
f:app: {}
f:pod-template-hash: {}
f:ownerReferences:
.: {}
k:{"uid":"292bfe3b-dd63-442e-95ce-c796ab5bdcc1"}:
.: {}
f:apiVersion: {}
f:blockOwnerDeletion: {}
f:controller: {}
f:kind: {}
f:name: {}
f:uid: {}
f:spec:
f:containers:
k:{"name":"tomcat"}:
.: {}
f:image: {}
f:imagePullPolicy: {}
f:name: {}
f:resources: {}
f:terminationMessagePath: {}
f:terminationMessagePolicy: {}
f:dnsPolicy: {}
f:enableServiceLinks: {}
f:restartPolicy: {}
f:schedulerName: {}
f:securityContext: {}
f:terminationGracePeriodSeconds: {}
manager: kube-controller-manager
operation: Update
time: "2020-05-04T03:50:47Z"
- apiVersion: v1
fieldsType: FieldsV1
fieldsV1:
f:status:
f:conditions:
k:{"type":"ContainersReady"}:
.: {}
f:lastProbeTime: {}
f:lastTransitionTime: {}
f:status: {}
f:type: {}
k:{"type":"Initialized"}:
.: {}
f:lastProbeTime: {}
f:lastTransitionTime: {}
f:status: {}
f:type: {}
k:{"type":"Ready"}:
.: {}
f:lastProbeTime: {}
f:lastTransitionTime: {}
f:status: {}
f:type: {}
f:containerStatuses: {}
f:hostIP: {}
f:phase: {}
f:podIP: {}
f:podIPs:
.: {}
k:{"ip":"10.244.2.7"}:
.: {}
f:ip: {}
f:startTime: {}
manager: kubelet
operation: Update
time: "2020-05-04T03:50:49Z"
name: tomcat6-7b84fb5fdc-5jh6t
namespace: default
ownerReferences:
- apiVersion: apps/v1
blockOwnerDeletion: true
controller: true
kind: ReplicaSet
name: tomcat6-7b84fb5fdc
uid: 292bfe3b-dd63-442e-95ce-c796ab5bdcc1
resourceVersion: "46229"
selfLink: /api/v1/namespaces/default/pods/tomcat6-7b84fb5fdc-5jh6t
uid: 2f661212-3b03-47e4-bcb8-79782d5c7578
spec:
containers:
- image: tomcat:6.0.53-jre8
imagePullPolicy: IfNotPresent
name: tomcat
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
volumeMounts:
- mountPath: /var/run/secrets/kubernetes.io/serviceaccount
name: default-token-bxqtw
readOnly: true
dnsPolicy: ClusterFirst
enableServiceLinks: true
nodeName: k8s-node2
priority: 0
restartPolicy: Always
schedulerName: default-scheduler
securityContext: {}
serviceAccount: default
serviceAccountName: default
terminationGracePeriodSeconds: 30
tolerations:
- effect: NoExecute
key: node.kubernetes.io/not-ready
operator: Exists
tolerationSeconds: 300
- effect: NoExecute
key: node.kubernetes.io/unreachable
operator: Exists
tolerationSeconds: 300
volumes:
- name: default-token-bxqtw
secret:
defaultMode: 420
secretName: default-token-bxqtw
status:
conditions:
- lastProbeTime: null
lastTransitionTime: "2020-05-04T03:50:47Z"
status: "True"
type: Initialized
- lastProbeTime: null
lastTransitionTime: "2020-05-04T03:50:49Z"
status: "True"
type: Ready
- lastProbeTime: null
lastTransitionTime: "2020-05-04T03:50:49Z"
status: "True"
type: ContainersReady
- lastProbeTime: null
lastTransitionTime: "2020-05-04T03:50:47Z"
status: "True"
type: PodScheduled
containerStatuses:
- containerID: docker://18eb0798384ea44ff68712cda9be94b6fb96265206c554a15cee28c288879304
image: tomcat:6.0.53-jre8
imageID: docker-pullable://tomcat@sha256:8c643303012290f89c6f6852fa133b7c36ea6fbb8eb8b8c9588a432beb24dc5d
lastState: {}
name: tomcat
ready: true
restartCount: 0
started: true
state:
running:
startedAt: "2020-05-04T03:50:49Z"
hostIP: 10.0.2.4
phase: Running
podIP: 10.244.2.7
podIPs:
- ip: 10.244.2.7
qosClass: BestEffort
startTime: "2020-05-04T03:50:47Z"
命令参考
service的意义
前面我们通过命令行的方式，部署和暴露了tomcat，实际上也可以通过yaml的方式来完成这些操作。
#这些操作实际上是为了获取Deployment的yaml模板
[root@k8s-node1 ~]# kubectl create deployment tomcat6 --image=tomcat:6.0.53-jre8 --dry-run -o yaml >tomcat6-deployment.yaml
W0504 04:13:28.265432 24263 helpers.go:535] --dry-run is deprecated and can be replaced with --dry-run=client.
[root@k8s-node1 ~]# ls tomcat6-deployment.yaml
tomcat6-deployment.yaml
[root@k8s-node1 ~]#
修改“tomcat6-deployment.yaml”内容如下：
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: tomcat6
name: tomcat6
spec:
replicas: 3
selector:
matchLabels:
app: tomcat6
template:
metadata:
labels:
app: tomcat6
spec:
containers:
- image: tomcat:6.0.53-jre8
name: tomcat
#部署
[root@k8s-node1 ~]# kubectl apply -f tomcat6-deployment.yaml
deployment.apps/tomcat6 configured
#查看资源
[root@k8s-node1 ~]# kubectl get all
NAME READY STATUS RESTARTS AGE
pod/tomcat6-7b84fb5fdc-5jh6t 1/1 Running 0 27m
pod/tomcat6-7b84fb5fdc-8lhwv 1/1 Running 0 27m
pod/tomcat6-7b84fb5fdc-j4qmh 1/1 Running 0 27m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 14h
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/tomcat6 3/3 3 3 27m
NAME DESIRED CURRENT READY AGE
replicaset.apps/tomcat6-7b84fb5fdc 3 3 3 27m
[root@k8s-node1 ~]#
kubectl expose deployment tomcat6 --port=80 --target-port=8080 --type=NodePort --dry-run -o yaml
apiVersion: v1
kind: Service
metadata:
creationTimestamp: null
labels:
app: tomcat6
name: tomcat6
spec:
ports:
- port: 80
protocol: TCP
targetPort: 8080
selector:
app: tomcat6
type: NodePort
status:
loadBalancer: {}
将这段输出和“tomcat6-deployment.yaml”进行拼接，表示部署完毕并进行暴露服务：
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: tomcat6
name: tomcat6
spec:
replicas: 3
selector:
matchLabels:
app: tomcat6
template:
metadata:
labels:
app: tomcat6
spec:
containers:
- image: tomcat:6.0.53-jre8
name: tomcat
---
apiVersion: v1
kind: Service
metadata:
creationTimestamp: null
labels:
app: tomcat6
name: tomcat6
spec:
ports:
- port: 80
protocol: TCP
targetPort: 8080
selector:
app: tomcat6
type: NodePort
部署并暴露服务
[root@k8s-node1 ~]# kubectl apply -f tomcat6-deployment.yaml
deployment.apps/tomcat6 created
service/tomcat6 created
查看服务和部署信息
[root@k8s-node1 ~]# kubectl get all
NAME READY STATUS RESTARTS AGE
pod/tomcat6-7b84fb5fdc-dsqmb 1/1 Running 0 4s
pod/tomcat6-7b84fb5fdc-gbmxc 1/1 Running 0 5s
pod/tomcat6-7b84fb5fdc-kjlc6 1/1 Running 0 4s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 14h
service/tomcat6 NodePort 10.96.147.210 <none> 80:30172/TCP 4s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/tomcat6 3/3 3 3 5s
NAME DESIRED CURRENT READY AGE
replicaset.apps/tomcat6-7b84fb5fdc 3 3 3 5s
[root@k8s-node1 ~]#
访问node1，node1和node3的30172端口：
[root@k8s-node1 ~]# curl -I http://192.168.56.{100,101,102}:30172/
HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
Accept-Ranges: bytes
ETag: W/"7454-1491118183000"
Last-Modified: Sun, 02 Apr 2017 07:29:43 GMT
Content-Type: text/html
Content-Length: 7454
Date: Mon, 04 May 2020 04:35:35 GMT
HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
Accept-Ranges: bytes
ETag: W/"7454-1491118183000"
Last-Modified: Sun, 02 Apr 2017 07:29:43 GMT
Content-Type: text/html
Content-Length: 7454
Date: Mon, 04 May 2020 04:35:35 GMT
HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
Accept-Ranges: bytes
ETag: W/"7454-1491118183000"
Last-Modified: Sun, 02 Apr 2017 07:29:43 GMT
Content-Type: text/html
Content-Length: 7454
Date: Mon, 04 May 2020 04:35:35 GMT
[root@k8s-node1 ~]#
Ingress
通过Ingress发现pod进行关联。基于域名访问
通过Ingress controller实现POD负载均衡
支持TCP/UDP 4层负载均衡和HTTP 7层负载均衡
步骤：
（1）部署Ingress controller
执行“k8s/ingress-controller.yaml”
[root@k8s-node1 k8s]# kubectl apply -f ingress-controller.yaml
namespace/ingress-nginx created
configmap/nginx-configuration created
configmap/tcp-services created
configmap/udp-services created
serviceaccount/nginx-ingress-serviceaccount created
clusterrole.rbac.authorization.k8s.io/nginx-ingress-clusterrole created
role.rbac.authorization.k8s.io/nginx-ingress-role created
rolebinding.rbac.authorization.k8s.io/nginx-ingress-role-nisa-binding created
clusterrolebinding.rbac.authorization.k8s.io/nginx-ingress-clusterrole-nisa-binding created
daemonset.apps/nginx-ingress-controller created
service/ingress-nginx created
[root@k8s-node1 k8s]#
查看
[root@k8s-node1 k8s]# kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
default tomcat6-7b84fb5fdc-dsqmb 1/1 Running 0 16m
default tomcat6-7b84fb5fdc-gbmxc 1/1 Running 0 16m
default tomcat6-7b84fb5fdc-kjlc6 1/1 Running 0 16m
ingress-nginx nginx-ingress-controller-9q6cs 0/1 ContainerCreating 0 40s
ingress-nginx nginx-ingress-controller-qx572 0/1 ContainerCreating 0 40s
kube-system coredns-546565776c-9sbmk 1/1 Running 1 14h
kube-system coredns-546565776c-t68mr 1/1 Running 1 14h
kube-system etcd-k8s-node1 1/1 Running 1 14h
kube-system kube-apiserver-k8s-node1 1/1 Running 1 14h
kube-system kube-controller-manager-k8s-node1 1/1 Running 1 14h
kube-system kube-flannel-ds-amd64-5xs5j 1/1 Running 2 13h
kube-system kube-flannel-ds-amd64-6xwth 1/1 Running 2 14h
kube-system kube-flannel-ds-amd64-fvnvx 1/1 Running 1 13h
kube-system kube-proxy-7tkvl 1/1 Running 1 13h
kube-system kube-proxy-mvlnk 1/1 Running 2 13h
kube-system kube-proxy-sz2vz 1/1 Running 1 14h
kube-system kube-scheduler-k8s-node1 1/1 Running 1 14h
[root@k8s-node1 k8s]#
这里master节点负责调度，具体执行交给node2和node3来完成，能够看到它们正在下载镜像
（2）创建Ingress规则
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: web
spec:
rules:
- host: tomcat6.kubenetes.com
http:
paths:
- backend:
serviceName: tomcat6
servicePort: 80
[root@k8s-node1 k8s]# touch ingress-tomcat6.yaml
#将上面的规则，添加到ingress-tomcat6.yaml文件中
[root@k8s-node1 k8s]# vi ingress-tomcat6.yaml
[root@k8s-node1 k8s]# kubectl apply -f ingress-tomcat6.yaml
ingress.extensions/web created
[root@k8s-node1 k8s]#
修改本机的hosts文件，添加如下的域名转换规则：
192.168.56.102 tomcat6.kubenetes.com
测试: http://tomcat6.kubenetes.com/
并且集群中即便有一个节点不可用，也不影响整体的运行。
安装kubernetes可视化界面——DashBoard
1、部署DashBoard
$ kubectl appy -f kubernetes-dashboard.yaml
文件在“k8s”源码目录提供
2、暴露DashBoard为公共访问
默认DashBoard只能集群内部访问，修改Service为NodePort类型，暴露到外部
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kube-system
spec:
type: NodePort
ports:
- port: 443
targetPort: 8443
nodePort: 3001
selector:
k8s-app: kubernetes-dashboard
访问地址：http://NodeIP:30001
3、创建授权账号
$ kubectl create serviceaccount dashboar-admin -n kube-sysem
$ kubectl create clusterrolebinding dashboar-admin --clusterrole=cluter-admin --serviceaccount=kube-system:dashboard-admin
$ kubectl describe secrets -n kube-system $( kubectl -n kube-system get secret |awk '/dashboard-admin/{print $1}' )
使用输出的token登录dashboard
kubesphere
默认的dashboard没啥用，我们用kubesphere可以打通全部的devops链路，kubesphere集成了很多套件，集群要求比较高
https://kubesphere.io
kuboard也很不错，集群要求不高
https://kuboard.cn/support/
1、简洁
kubesphere是一款面向云原声设计的开源项目，在目前主流容器调度平台kubernets智商构建的分布式多用户容器管理平台，提供简单易用的操作界面以及向导式操作方式，在降低用户使用容器调度平台学习成本的同时，极大降低开发、测试、运维的日常工作的复杂度。
2、安装前提提交
1、安装helm（master节点执行）
helm是kubernetes的包管理器。包管理器类似于在Ubuntu中使用的apt，centos中的yum或者python中的pip一样，能够快速查找，下载和安装软件包。Helm有客户端组件helm和服务端组件Tiller组成，能够将一组K8S资源打包统一管理，是查找、共享和使用为Kubernetes构建的软件的最佳方式。
1）安装
curl -L https://git.io/get_helm.sh|bash
由于被墙的原因，使用我们给定的get_helm.sh。
[root@k8s-node1 k8s]# ll
total 68
-rw-r--r-- 1 root root 7149 Feb 27 01:58 get_helm.sh
-rw-r--r-- 1 root root 6310 Feb 28 05:16 ingress-controller.yaml
-rw-r--r-- 1 root root 209 Feb 28 13:18 ingress-demo.yml
-rw-r--r-- 1 root root 236 May 4 05:09 ingress-tomcat6.yaml
-rwxr--r-- 1 root root 15016 Feb 26 15:05 kube-flannel.yml
-rw-r--r-- 1 root root 4737 Feb 26 15:38 kubernetes-dashboard.yaml
-rw-r--r-- 1 root root 3841 Feb 27 01:09 kubesphere-complete-setup.yaml
-rw-r--r-- 1 root root 392 Feb 28 11:33 master_images.sh
-rw-r--r-- 1 root root 283 Feb 28 11:34 node_images.sh
-rw-r--r-- 1 root root 1053 Feb 28 03:53 product.yaml
-rw-r--r-- 1 root root 931 May 3 10:08 Vagrantfile
[root@k8s-node1 k8s]# sh get_helm.sh
Downloading https://get.helm.sh/helm-v2.16.6-linux-amd64.tar.gz
Preparing to install helm and tiller into /usr/local/bin
helm installed into /usr/local/bin/helm
tiller installed into /usr/local/bin/tiller
Run 'helm init' to configure helm.
[root@k8s-node1 k8s]#
2）验证版本
helm version
3）创建权限（master执行）
创建helm-rbac.yaml，写入如下内容
apiVersion: v1
kind: ServiceAccount
metadata:
name: tiller
namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: tiller
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: cluster-admin
subjects:
- kind: ServiceAccount
name: kubernetes-dashboard
namespace: kube-system
应用配置：
[root@k8s-node1 k8s]# kubectl apply -f helm-rbac.yaml
serviceaccount/tiller created
clusterrolebinding.rbac.authorization.k8s.io/tiller created
[root@k8s-node1 k8s]#
2、安装Tilller（Master执行）
1、初始化
[root@k8s-node1 k8s]# helm init --service-account=tiller --tiller-image=sapcc/tiller:v2.16.3 --history-max 300
Creating /root/.helm
Creating /root/.helm/repository
Creating /root/.helm/repository/cache
Creating /root/.helm/repository/local
Creating /root/.helm/plugins
Creating /root/.helm/starters
Creating /root/.helm/cache/archive
Creating /root/.helm/repository/repositories.yaml
Adding stable repo with URL: https://kubernetes-charts.storage.googleapis.com
Adding local repo with URL: http://127.0.0.1:8879/charts
$HELM_HOME has been configured at /root/.helm.
Tiller (the Helm server-side component) has been installed into your Kubernetes Cluster.
Please note: by default, Tiller is deployed with an insecure 'allow unauthenticated users' policy.
To prevent this, run `helm init` with the --tiller-tls-verify flag.
For more information on securing your installation see: https://v2.helm.sh/docs/securing_installation/
[root@k8s-node1 k8s]#
–tiller-image 指定镜像，否则会被墙，等待节点上部署的tiller完成即可。
[root@k8s-node1 k8s]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-546565776c-9sbmk 1/1 Running 3 23h
coredns-546565776c-t68mr 1/1 Running 3 23h
etcd-k8s-node1 1/1 Running 3 23h
kube-apiserver-k8s-node1 1/1 Running 3 23h
kube-controller-manager-k8s-node1 1/1 Running 3 23h
kube-flannel-ds-amd64-5xs5j 1/1 Running 4 22h
kube-flannel-ds-amd64-6xwth 1/1 Running 5 23h
kube-flannel-ds-amd64-fvnvx 1/1 Running 4 22h
kube-proxy-7tkvl 1/1 Running 3 22h
kube-proxy-mvlnk 1/1 Running 4 22h
kube-proxy-sz2vz 1/1 Running 3 23h
kube-scheduler-k8s-node1 1/1 Running 3 23h
kubernetes-dashboard-975499656-jxczv 0/1 ImagePullBackOff 0 7h45m
tiller-deploy-8cc566858-67bxb 1/1 Running 0 31s
[root@k8s-node1 k8s]#
查看集群的所有节点信息：
kubectl get node -o wide
[root@k8s-node1 k8s]# kubectl get node -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
k8s-node1 Ready master 23h v1.17.3 10.0.2.15 <none> CentOS Linux 7 (Core) 3.10.0-957.12.2.el7.x86_64 docker://19.3.8
k8s-node2 Ready <none> 22h v1.17.3 10.0.2.4 <none> CentOS Linux 7 (Core) 3.10.0-957.12.2.el7.x86_64 docker://19.3.8
k8s-node3 Ready <none> 22h v1.17.3 10.0.2.5 <none> CentOS Linux 7 (Core) 3.10.0-957.12.2.el7.x86_64 docker://19.3.8
[root@k8s-node1 k8s]#
2、测试
helm install stable/nginx-ingress --name nginx-ingress
最小化安装 KubeSphere
若集群可用 CPU > 1 Core 且可用内存 > 2 G，可以使用以下命令最小化安装 KubeSphere：
kubectl apply -f https://raw.githubusercontent.com/kubesphere/ks-installer/master/kubesphere-minimal.yaml
提示：若您的服务器提示无法访问 GitHub，可将 kubesphere-minimal.yaml 或 kubesphere-complete-setup.yaml 文件保存到本地作为本地的静态文件，再参考上述命令进行安装。
- 查看滚动刷新的安装日志，请耐心等待安装成功。
$ kubectl logs -n kubesphere-system $(kubectl get pod -n kubesphere-system -l app=ks-install -o jsonpath='{.items[0].metadata.name}') -f
说明：安装过程中若遇到问题，也可以通过以上日志命令来排查问题。