目录
[3.1 安装要求](#3.1 安装要求)
[3.2 为每台服务器完成前置设置](#3.2 为每台服务器完成前置设置)
[3.3 为每台服务器安装kubelet、kubeadm、kubectl](#3.3 为每台服务器安装kubelet、kubeadm、kubectl)
[4.1 master服务器](#4.1 master服务器)
[4.2 node1、node2服务器](#4.2 node1、node2服务器)
[4.3 初始化主节点](#4.3 初始化主节点)
[4.4 work节点加入集群](#4.4 work节点加入集群)
[6.1 安装](#6.1 安装)
[6.2 暴露端口](#6.2 暴露端口)
[6.3 访问web界面](#6.3 访问web界面)
[6.4 创建访问账号](#6.4 创建访问账号)
[6.5 生成令牌](#6.5 生成令牌)
[6.6 登录](#6.6 登录)
一、创建3台虚拟机
具体操作步骤可以参考之前的教程,建议是先安装一台,然后克隆虚拟机,这样速度快。
注意:在克隆时记得修改Mac地址、IP地址、UUID和主机名。(最后别忘了保存下快照~)
安装VMware虚拟机、Linux系统(CentOS7)_何苏三月的博客-CSDN博客
克隆Linux系统(centos)_linux克隆_何苏三月的博客-CSDN博客
二、为每台虚拟机安装Docker
请参考:Docker安装、常见命令、安装常见容器(Mysql、Redis等)_docker redis 容器_何苏三月的博客-CSDN博客
教程中安装docker的命令
bash
yum install docker-ce docker-ce-cli containerd.io
原来是默认安装最新版,这里需要指定一下版本,目的是保障后续安装k8s不出问题:
bash
yum install -y docker-ce-20.10.7 docker-ce-cli-20.10.7 containerd.io-1.4.6
其他步骤不变。
三、安装kubelet
3.1 安装要求
-
一台兼容的 Linux 主机。Kubernetes 项目为基于 Debian 和 Red Hat 的 Linux 发行版以及一些不提供包管理器的发行版提供通用的指令。
-
每台机器 2 GB 或更多的 RAM (如果少于这个数字将会影响你应用的运行内存)
-
2 CPU 核或更多
-
集群中的所有机器的网络彼此均能相互连接(公网和内网都可以)
- 设置防火墙放行规则
-
节点之中不可以有重复的主机名、MAC 地址或 product_uuid。请参见这里了解更多详细信息。
- 设置不同hostname
-
开启机器上的某些端口。请参见这里 了解更多详细信息。
- 内网互信
-
禁用交换分区。为了保证 kubelet 正常工作,你 必须 禁用交换分区。
- 永久关闭
3.2 为每台服务器完成前置设置
bash
#各个机器设置自己的域名
hostnamectl set-hostname xxxx
# 将 SELinux 设置为 permissive 模式(相当于将其禁用)
sudo setenforce 0
sudo sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config
#关闭swap
swapoff -a
sed -ri 's/.*swap.*/#&/' /etc/fstab
#允许 iptables 检查桥接流量
cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
br_netfilter
EOF
cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sudo sysctl --system
3.3 为每台服务器安装kubelet、kubeadm、kubectl
kubelet - "厂长"
kubectl - 程序员敲命令行的命令窗
kubeadm - 引导创建集群的
bash
# 1.先配置K8S去哪儿下载的地址信息
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
exclude=kubelet kubeadm kubectl
EOF
# 2. 安装
sudo yum install -y kubelet-1.20.9 kubeadm-1.20.9 kubectl-1.20.9 --disableexcludes=kubernetes
# 3. 启动kubelet
sudo systemctl enable --now kubelet
💡**systemctl status kubelet
** 查看状态会发现,kubelet 现在每隔几秒就会重启,因为它陷入了一个等待 kubeadm 指令的死循环。这是正常现象不用管!
四、使用kubeadm引导集群
4.1 master服务器
下载各个机器需要的镜像,以下只需要在master机器上执行:
bash
# 1. 定义一个for循环,需要的东西下载
sudo tee ./images.sh <<-'EOF'
#!/bin/bash
images=(
kube-apiserver:v1.20.9
kube-proxy:v1.20.9
kube-controller-manager:v1.20.9
kube-scheduler:v1.20.9
coredns:1.7.0
etcd:3.4.13-0
pause:3.2
)
for imageName in ${images[@]} ; do
docker pull registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/$imageName
done
EOF
# 2. 赋予权限,让它下载这些东西
chmod +x ./images.sh && ./images.sh
4.2 node1、node2服务器
从图上可以知道,从节点也需要安装kube-proxy。我们可以只下载这个镜像,当然了为了避免出现意外,我们也可以都下载下来。
方法完全参考4.1
4.3 初始化主节点
1.首先给所有的服务器都添加一下k8s110这台服务器的域名映射
bash
#所有机器添加master域名映射,以下需要修改为自己的内网ip地址
echo "192.168.37.110 cluster-endpoint" >> /etc/hosts
2.然后只在k8s110这台服务器上执行主节点初始化过程:
bash
#主节点初始化
kubeadm init \
--apiserver-advertise-address=192.168.37.110 \
--control-plane-endpoint=cluster-endpoint \
--image-repository registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images \
--kubernetes-version v1.20.9 \
--service-cidr=10.96.0.0/16 \
--pod-network-cidr=192.168.50.0/24
#要求所有网络范围不重叠 --pod-network-cidr --service-cidr --apiserver-advertise-address 都不能重叠
如果出现上述错误,则执行如下命令:
bash
sysctl -w net.ipv4.ip_forward=1
然后重新执行
最后看到如下画面则表示初始化成功!
这段还比较重要的,它告诉我们怎么使用这个集群信息等等,所以我们把文本单独复制出来
diff
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
Alternatively, if you are the root user, you can run:
export KUBECONFIG=/etc/kubernetes/admin.conf
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 control-plane nodes by copying certificate authorities
and service account keys on each node and then running the following as root:
kubeadm join cluster-endpoint:6443 --token 3e54se.alzs9d1mkf30f25w \
--discovery-token-ca-cert-hash sha256:689c076e294bdbb588103a51aaa7248b8a0df34bde634a6189d311ad46a02856 \
--control-plane
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join cluster-endpoint:6443 --token 3e54se.alzs9d1mkf30f25w \
--discovery-token-ca-cert-hash sha256:689c076e294bdbb588103a51aaa7248b8a0df34bde634a6189d311ad46a02856
那么按照它的要求一步一步执行吧!
3.按要求创建文件夹复制文件给予权限等操作
bash
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
然后我们查看一下集群的所有结点:
bash
#查看集群所有节点
kubectl get nodes
发现k8s110这台服务器就是master节点了,但是它的状态是NotReady。
没关系按照它的要求继续执行,下一步说需要安装一个网络插件。
4.安装网络插件
可以有多种安装选择,我们就用calico
bash
curl https://docs.projectcalico.org/v3.20/manifests/calico.yaml -O
下载成功,我们calico.yaml配置文件就有了。
重要提示💡:如果我们在初始化主节点时,修改了--pod-network-cidr=192.168.0.0/16,那么我们就要进入这个配置文件,将我们修改后的ip地址写上去。
ok,有了这个配置文件,就可以通过如下命令为k8s安装calico插件所需要的东西了
bash
#根据配置文件,给集群创建资源(以后通过该命令为k8s创建资源,不限于calico)
kubectl apply -f calico.yaml
然后执行命令安装calico网络插件
如果出现上述提示,说明我们的yaml文件有可能换行符搞错了等等。
再重新下载就好了。
我们如何查看集群部署了哪些应用呢?
bash
# 查看集群部署了哪些应用
docker ps
# 等价于
kubectl get pods -A
# 运行中的应用在docker里面叫容器,在k8s里面叫Pod,至于为什么,后续再讲
以上,master节点就准备就绪了!
4.4 work节点加入集群
前面初始化主节点成功后的提示中有步骤:
bash
kubeadm join cluster-endpoint:6443 --token 3e54se.alzs9d1mkf30f25w \
--discovery-token-ca-cert-hash sha256:689c076e294bdbb588103a51aaa7248b8a0df34bde634a6189d311ad46a02856
我们只需要将它在另外两台服务器各自执行即可。
如果加入报错,请查看是否已经关闭了防火墙,确保关闭防火墙然后执行:
bash
sysctl -w net.ipv4.ip_forward=1
ok,然后去master查看一下节点信息。
我们也可以通过linux的命令watch -n 1kubectl get pods -A,每一秒查看一下状态
OK了,我们再看看
至此,K8S集群就跑起来了。
五、token过期怎么办?
token超过24小时就失效了,如果我们还没有加入从节点,或者想加入新的从节点,可以在master节点执行如下命令,让它重新生成
bash
kubeadm token create --print-join-command
六、安装可视化界面dashboard
6.1 安装
bash
kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.3.1/aio/deploy/recommended.yaml
如果网络不好安装不了就复制下面的,将它写入到一个yaml文件中,然后执行该文件即可:
bash
# Copyright 2017 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
apiVersion: v1
kind: Namespace
metadata:
name: kubernetes-dashboard
---
apiVersion: v1
kind: ServiceAccount
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kubernetes-dashboard
---
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kubernetes-dashboard
spec:
ports:
- port: 443
targetPort: 8443
selector:
k8s-app: kubernetes-dashboard
---
apiVersion: v1
kind: Secret
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard-certs
namespace: kubernetes-dashboard
type: Opaque
---
apiVersion: v1
kind: Secret
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard-csrf
namespace: kubernetes-dashboard
type: Opaque
data:
csrf: ""
---
apiVersion: v1
kind: Secret
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard-key-holder
namespace: kubernetes-dashboard
type: Opaque
---
kind: ConfigMap
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard-settings
namespace: kubernetes-dashboard
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kubernetes-dashboard
rules:
# Allow Dashboard to get, update and delete Dashboard exclusive secrets.
- apiGroups: [""]
resources: ["secrets"]
resourceNames: ["kubernetes-dashboard-key-holder", "kubernetes-dashboard-certs", "kubernetes-dashboard-csrf"]
verbs: ["get", "update", "delete"]
# Allow Dashboard to get and update 'kubernetes-dashboard-settings' config map.
- apiGroups: [""]
resources: ["configmaps"]
resourceNames: ["kubernetes-dashboard-settings"]
verbs: ["get", "update"]
# Allow Dashboard to get metrics.
- apiGroups: [""]
resources: ["services"]
resourceNames: ["heapster", "dashboard-metrics-scraper"]
verbs: ["proxy"]
- apiGroups: [""]
resources: ["services/proxy"]
resourceNames: ["heapster", "http:heapster:", "https:heapster:", "dashboard-metrics-scraper", "http:dashboard-metrics-scraper"]
verbs: ["get"]
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
rules:
# Allow Metrics Scraper to get metrics from the Metrics server
- apiGroups: ["metrics.k8s.io"]
resources: ["pods", "nodes"]
verbs: ["get", "list", "watch"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kubernetes-dashboard
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: Role
name: kubernetes-dashboard
subjects:
- kind: ServiceAccount
name: kubernetes-dashboard
namespace: kubernetes-dashboard
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: kubernetes-dashboard
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: kubernetes-dashboard
subjects:
- kind: ServiceAccount
name: kubernetes-dashboard
namespace: kubernetes-dashboard
---
kind: Deployment
apiVersion: apps/v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kubernetes-dashboard
spec:
replicas: 1
revisionHistoryLimit: 10
selector:
matchLabels:
k8s-app: kubernetes-dashboard
template:
metadata:
labels:
k8s-app: kubernetes-dashboard
spec:
containers:
- name: kubernetes-dashboard
image: kubernetesui/dashboard:v2.3.1
imagePullPolicy: Always
ports:
- containerPort: 8443
protocol: TCP
args:
- --auto-generate-certificates
- --namespace=kubernetes-dashboard
# Uncomment the following line to manually specify Kubernetes API server Host
# If not specified, Dashboard will attempt to auto discover the API server and connect
# to it. Uncomment only if the default does not work.
# - --apiserver-host=http://my-address:port
volumeMounts:
- name: kubernetes-dashboard-certs
mountPath: /certs
# Create on-disk volume to store exec logs
- mountPath: /tmp
name: tmp-volume
livenessProbe:
httpGet:
scheme: HTTPS
path: /
port: 8443
initialDelaySeconds: 30
timeoutSeconds: 30
securityContext:
allowPrivilegeEscalation: false
readOnlyRootFilesystem: true
runAsUser: 1001
runAsGroup: 2001
volumes:
- name: kubernetes-dashboard-certs
secret:
secretName: kubernetes-dashboard-certs
- name: tmp-volume
emptyDir: {}
serviceAccountName: kubernetes-dashboard
nodeSelector:
"kubernetes.io/os": linux
# Comment the following tolerations if Dashboard must not be deployed on master
tolerations:
- key: node-role.kubernetes.io/master
effect: NoSchedule
---
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: dashboard-metrics-scraper
name: dashboard-metrics-scraper
namespace: kubernetes-dashboard
spec:
ports:
- port: 8000
targetPort: 8000
selector:
k8s-app: dashboard-metrics-scraper
---
kind: Deployment
apiVersion: apps/v1
metadata:
labels:
k8s-app: dashboard-metrics-scraper
name: dashboard-metrics-scraper
namespace: kubernetes-dashboard
spec:
replicas: 1
revisionHistoryLimit: 10
selector:
matchLabels:
k8s-app: dashboard-metrics-scraper
template:
metadata:
labels:
k8s-app: dashboard-metrics-scraper
annotations:
seccomp.security.alpha.kubernetes.io/pod: 'runtime/default'
spec:
containers:
- name: dashboard-metrics-scraper
image: kubernetesui/metrics-scraper:v1.0.6
ports:
- containerPort: 8000
protocol: TCP
livenessProbe:
httpGet:
scheme: HTTP
path: /
port: 8000
initialDelaySeconds: 30
timeoutSeconds: 30
volumeMounts:
- mountPath: /tmp
name: tmp-volume
securityContext:
allowPrivilegeEscalation: false
readOnlyRootFilesystem: true
runAsUser: 1001
runAsGroup: 2001
serviceAccountName: kubernetes-dashboard
nodeSelector:
"kubernetes.io/os": linux
# Comment the following tolerations if Dashboard must not be deployed on master
tolerations:
- key: node-role.kubernetes.io/master
effect: NoSchedule
volumes:
- name: tmp-volume
emptyDir: {}
6.2 暴露端口
bash
kubectl edit svc kubernetes-dashboard -n kubernetes-dashboard
type: ClusterIP 改为 type: NodePort
相当于docker中将内部的端口映射到linux的某个端口
找到放行的端口
bash
kubectl get svc -A |grep kubernetes-dashboard
## 如果是云服务器,找到端口,在安全组放行
6.3 访问web界面
访问: https://集群任意IP:端口 https://192.168.37.110:31820/
发现虚拟机部署的无法访问,云服务器则没有问题。
我后面试了试Google、Edge都不行,华为浏览器、火狐浏览器可以访问到:
具体怎么解决,这个我放到后面有时间再处理吧~
6.4 创建访问账号
创建一个配置文件dash-usr.yaml
bash
#创建访问账号,准备一个yaml文件; vi dash.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
name: admin-user
namespace: kubernetes-dashboard
---
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: kubernetes-dashboard
6.5 生成令牌
这个可视化界面是通过令牌登录的,我们可以通过如下命令生成访问令牌:
bash
#获取访问令牌
kubectl -n kubernetes-dashboard get secret $(kubectl -n kubernetes-dashboard get sa/admin-user -o jsonpath="{.secrets[0].name}") -o go-template="{{.data.token | base64decode}}"
6.6 登录
七、写在后面的话
值得注意的是,我们的这些kubectl命令都需要在master节点上运行,别整岔劈了!
另外,我们重启后,k8s集群正常来说就会自动启动,只不过部分应用需要时间慢慢启动,等他们全部running
如果发现没有重启成功,那么检查一下swap交换分区是不是没有关闭?防火墙是不是打开了?docker是不是都启动了?
遇事不要慌,逐一进行排查,这也是处理问题的能力。我在搭建的过程中,也遇到了不少的坑,正常。不过只要严格按照上述过程执行,我相信问题不大的。
好了,我们下一个阶段见!