Kubernetes安装（Ubuntu18.4）
Ubuntu18阿里源
–备份/etc/apt/sources.list
cp /etc/apt/sources.list /etc/apt/sources.list.bak
–修改国内源
将/etc/apt/sources.list替换成如下内容
deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
–更新
sudo apt-get update
一 、docker安装
1、更新系统软件
sudo apt-get update
2、安装docker依赖以及vim net-tools openssh-server
sudo apt-get install -y vim net-tools openssh-server apt-transport-https ca-certificates curl gnupg-agent software-properties-common
3、添加docker官方秘钥
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
4、验证指纹
sudo apt-key fingerprint 0EBFCD88
5、添加仓库
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
6、更新apt包索引
sudo apt-get update
7、安装最新版本docker
sudo apt-get install -y docker-ce docker-ce-cli containerd.io
–安装指定版本
（1）在仓库中列出可用版本
apt-cache madison docker-ce
（2）安装指定版本第二列字符串是版本号，替换下面命令中的VERSION_STRING
sudo apt-get install docker-ce=<VERSION_STRING> docker-ce-cli=<VERSION_STRING> containerd.io
二、安装kubernetes
1、创建配置文件
sudo touch /etc/apt/sources.list.d/kubernetes.list
2、添加写权限
sudo chmod 666 /etc/apt/sources.list.d/kubernetes.list
3、在上面文件中添加一下内容
deb http://mirrors.ustc.edu.cn/kubernetes/apt kubernetes-xenial main
或者使用
echo "deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main" | sudo tee -a /etc/apt/sources.list.d/kubernetes.list
4、更新操作系统源
sudo apt update
会输出签名认证失败
The following signatures couldn’t be verified
because the public key is not available: NO_PUBKEY
6A030B21BA07F4FB
5、记住上面的 NO_PUBKEY后8位，添加认证Key，keys后面跟NO_PUBKEY后8位（BA07F4FB）
gpg --keyserver keyserver.ubuntu.com --recv-keys BA07F4FB
6、输入一下命令，OK说明成功，注意对应NO_PUBKEY后8位
gpg --export --armor BA07F4FB | sudo apt-key add -
7、再次更新系统下载源
sudo apt update
8、禁用防火墙
sudo ufw disable
9、关闭swap交换分区
（1）关闭
sudo swapoff -a
（2）修改配置文件永久关闭
sudo sed -i 's/.*swap.*/#&/' /etc/fstab
10、禁止selinux
（1）安装操控selinux的命令
sudo apt install -y selinux-utils
（2）禁止selinux
setenforce 0
（3）重启操作系统（阿里云可能需要重启实例）
shutdown -r now
（4）查看selinux是否已经关闭
sudo getenforce
11、查看swap交换分区是否关闭
free -m
11、安装kubenetes
sudo apt-get install -y kubelet=1.18.5-00 kubeadm=1.18.5-00 kubectl=1.18.5-00 kubernetes-cni=0.8.6-00
12、设置开机自启
sudo systemctl enable kubelet && systemctl start kubelet
13、重启(阿里云重启实例)
sudo shutdown -r now
14、验证安装，尝试使用kubectl命令
kubectl get nodes
会提示The connection to the server localhost:8080 was refused - did you specify the right host or port?（说明安装成功）
15、查看当前kubernetes版本
kubectl version
三、master节点的初始化
1、显示kubeadm默认初始化文件，打印出来，写入kubeadm-config.conf文件。
kubeadm config print init-defaults ClusterConfiguration> kubeadm-config.conf
2、修改kubeadm-config.conf文件
advertiseAddress 改为本主节点地址(192.168.x.x)
imageRepository 修改镜像源(registry.aliyuncs.com/google_containers)
kubernetesVersion修改为对应版本
添加子网网络
networking:
dnsDomain: cluster.local
podSubnet: 10.244.0.0/16
serviceSubnet: 10.96.0.0/12
scheduler: {
}
这里的10.244.0.0/16 和 10.96.0.0/12分别是k8s内部pods和services的子网网络，最好使用这个地址，后续flannel网络需要用到。
3、查看一下都需要哪些镜像文件需要拉取
kubeadm config images list --config kubeadm-config.conf
4、拉取镜像
kubeadm config images pull --config ./kubeadm-config.conf
这里可以拉取国内镜像然后改名
5、初始化并且启动
sudo kubeadm init --config ./kubeadm-config.conf
6、保存输出内容，写入文件，node节点加入需要用到
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/clusteradministration/addons/
You can now join any number of machines by running
the following on each node
as root:
kubeadm join 192.168.x.x:6443 --token
xxxxxx.xxxxxxxxxxxxxx --discovery-token-ca-certhash
sha256:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
7、复制admin.conf文件并更改属主
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
8、验证
kubectl get nodes
此时NotReady
9、下载flannel
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
下载不了直接复制
---
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
name: psp.flannel.unprivileged
annotations:
seccomp.security.alpha.kubernetes.io/allowedProfileNames: docker/default
seccomp.security.alpha.kubernetes.io/defaultProfileName: docker/default
apparmor.security.beta.kubernetes.io/allowedProfileNames: runtime/default
apparmor.security.beta.kubernetes.io/defaultProfileName: runtime/default
spec:
privileged: false
volumes:
- configMap
- secret
- emptyDir
- hostPath
allowedHostPaths:
- pathPrefix: "/etc/cni/net.d"
- pathPrefix: "/etc/kube-flannel"
- pathPrefix: "/run/flannel"
readOnlyRootFilesystem: false
# Users and groups
runAsUser:
rule: RunAsAny
supplementalGroups:
rule: RunAsAny
fsGroup:
rule: RunAsAny
# Privilege Escalation
allowPrivilegeEscalation: false
defaultAllowPrivilegeEscalation: false
# Capabilities
allowedCapabilities: ['NET_ADMIN', 'NET_RAW']
defaultAddCapabilities: []
requiredDropCapabilities: []
# Host namespaces
hostPID: false
hostIPC: false
hostNetwork: true
hostPorts:
- min: 0
max: 65535
# SELinux
seLinux:
# SELinux is unused in CaaSP
rule: 'RunAsAny'
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: flannel
rules:
- apiGroups: ['extensions']
resources: ['podsecuritypolicies']
verbs: ['use']
resourceNames: ['psp.flannel.unprivileged']
- apiGroups:
- ""
resources:
- pods
verbs:
- get
- apiGroups:
- ""
resources:
- nodes
verbs:
- list
- watch
- apiGroups:
- ""
resources:
- nodes/status
verbs:
- patch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: flannel
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: flannel
subjects:
- kind: ServiceAccount
name: flannel
namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: flannel
namespace: kube-system
---
kind: ConfigMap
apiVersion: v1
metadata:
name: kube-flannel-cfg
namespace: kube-system
labels:
tier: node
app: flannel
data:
cni-conf.json: |
{
"name": "cbr0",
"cniVersion": "0.3.1",
"plugins": [
{
"type": "flannel",
"delegate": {
"hairpinMode": true,
"isDefaultGateway": true
}
},
{
"type": "portmap",
"capabilities": {
"portMappings": true
}
}
]
}
net-conf.json: |
{
"Network": "10.244.0.0/16",
"Backend": {
"Type": "vxlan"
}
}
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: kube-flannel-ds
namespace: kube-system
labels:
tier: node
app: flannel
spec:
selector:
matchLabels:
app: flannel
template:
metadata:
labels:
tier: node
app: flannel
spec:
affinity:
nodeAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
nodeSelectorTerms:
- matchExpressions:
- key: kubernetes.io/os
operator: In
values:
- linux
hostNetwork: true
priorityClassName: system-node-critical
tolerations:
- operator: Exists
effect: NoSchedule
serviceAccountName: flannel
initContainers:
- name: install-cni
image: quay.io/coreos/flannel:v0.13.0-rc2
command:
- cp
args:
- -f
- /etc/kube-flannel/cni-conf.json
- /etc/cni/net.d/10-flannel.conflist
volumeMounts:
- name: cni
mountPath: /etc/cni/net.d
- name: flannel-cfg
mountPath: /etc/kube-flannel/
containers:
- name: kube-flannel
image: quay.io/coreos/flannel:v0.13.0-rc2
command:
- /opt/bin/flanneld
args:
- --ip-masq
- --kube-subnet-mgr
resources:
requests:
cpu: "100m"
memory: "50Mi"
limits:
cpu: "100m"
memory: "50Mi"
securityContext:
privileged: false
capabilities:
add: ["NET_ADMIN", "NET_RAW"]
env:
- name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
volumeMounts:
- name: run
mountPath: /run/flannel
- name: flannel-cfg
mountPath: /etc/kube-flannel/
volumes:
- name: run
hostPath:
path: /run/flannel
- name: cni
hostPath:
path: /etc/cni/net.d
- name: flannel-cfg
configMap:
name: kube-flannel-cfg
10、编辑这个文件，确保flannel网络是对的,找到net-conf.json标记
的内容是否正确。
net-conf.json: |
{
"Network": "10.244.0.0/16",
"Backend": {
"Type": "vxlan"
}
这个"10.244.0.0/16"和 ./kubeadm-config.conf中的podsubnet的地址
要一致。
11、应用当前flannel配置文件
kubectl apply -f kube-flannel.yml
12、设置开机自启并启动kubelet
sudo systemctl enable kubelet
sudo systemctl start kubelet
此时是再次kubectl get nodes 会显示master节点Ready
四、node节点(初始化)加入已存在的k8s集群
1、将master节点的/etc/kubernetes/admin.conf文件发送到当前node主机
scp /etc/kubernetes/admin.conf 节点1用户名@192.168.x.x:/home/xxx
2、创建kube配置文件环境（这里的admin.conf使用master传过来的）
mkdir -p $HOME/.kube
sudo cp -i $HOME/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
3、加入集群
这里用的是kubeadm join指令也就是之前初始化master节点时的最后输出的命令
sudo kubeadm join 192.168.x.x:6443 --token xxxxxxxxxxxxxxx --discovery-token-ca-cert-hash sha256:xxxxxxxxxxxxxxxxxxxxxx
注意这里使用的hash应该是master主机 kubeadm init成功之后生成的hash码。
例如：
kubeadm join 192.168.64.131:6443 --token xxxxx.xxxxxxxxxx --discovery-token-ca-cert-hash sha256:xxxxxxxxxxxxxxxxxxxxxxxxxxxx
token有效时间为24小时，如超过24小时需要master重新生成token以及hash码，也可生成无限期。
-生成token
kubeadm token create
列如：
[kubeadm] WARNING: starting in 1.8, tokens expire after 24 hours by default (if you require a non-expiring token use --ttl 0)
xxxxxx.xxxxxxxxxxxx
-生成hash码（hash值一般不会变，生成的和原来一样）
openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'
列如：
0fd95a9bc67a7bf0ef42da968a0d55d92e52898ec37asdfasfdadfa
查看token
kubeadm token list
或使用一下命令从新生成并输出token
kubeadm token create --print-join-command
4、如果主机名相同会报错，修改主机名，/etc/hostname文件
5、可能会遇到如下错误，删除掉 /etc/kubernetes/pki/ca.crt再加入master
[ERROR FileAvailable--etc-kubernetes-pki-ca.crt]: /etc/kubernetes/pki/ca.crt already exists
rm /etc/kubernetes/pki/ca.crt
6、node主机应用flannel网络
（1）将master节点中的kube-flannel.yml发送到当前node主机
sudo scp kube-flannel.yml 节点1用户名@节点1ip:/home/xxx
（2）node主机启用flannel网络
kubectl apply -f kube-flannel.yml
五、pod手动驱离（deployment调度器创建的pod）
（1）将pod所在节点设置为不可调度状态
驱动node节点上的Pod（先设置node为cordon不可调度状态，然后驱逐Pod）
kubectl drain <node name>
（2）删除节点上的pod(此时pod会被deployment重新创建到别的节点上，如没有可用节点将会导致pod处于Pending状态)
kubectl delete pod <pod name>
（3）删除节点
kubectl delete node <node name>
–恢复节点为可调度状态
kubectl uncordon <node name>
此时会将处于Pending状态的pod调度到该节点
六、kubectl创建deployment调度器以及kubectl基本操作
1、创建yaml文件
apiVersion: apps/v1
kind: Deployment
metadata:
name: mydeployment
labels:
app: myapp
spec:
replicas: 1
selector:
matchLabels:
app: app
template:
metadata:
labels:
app: app
spec:
hostNetwork: true
dnsPolicy: ClusterFirstWithHostNet
containers:
- name: app1
image: myapp:v1
imagePullPolicy: IfNotPresent
ports:
- containerPort: 8880
- name: app2
image: myapp:v2
imagePullPolicy: IfNotPresent
ports:
- containerPort: 8881
replicas: 1期望维持的pod副本数量。
这里使用hostNetwork: true使pod使用节点网络，此时节点不能创建期望值的pod副本（端口冲突）。
image: myapp:v2 使用的镜像及版本。
imagePullPolicy: IfNotPresent表示如果当前pod所在节点有则使用本地镜像，没有则从远程仓库获
ports:
- containerPort: 8880容器暴露的端口，由于使用hostNetwork: true此设置不写也一样。
2、使用yaml文件创建deployment调度器
kubectl apply -f xxxx.yaml --record
3、查看node节点
kubectl get node -o wide
4、查看所有pod
kubectl get pod -o wide
5、查看指定pod
kubectl get pod <pod name>
6、以JSON格式输出POD信息
kubectl get pod <pod name> --output json
7、以yaml格式输出POD信息
kubectl get pod <pod name> --output yaml
8、删除pod
kubectl delete pod <pod name>
删除调度器管理的pod会被调度器再次创建，以维持期望值的pod数量
9、查看deployment调度器
kubectl get deploy <deployment name> -o wide
10、删除deployment调度器
kubectl delete deploy <deployment name>
此时所有由该调度器管理的pod都会陆续退出
11、查看node节点
kubectl get node -o wide
12、删除node节点
kubectl delete node <node name>
七、deployment滚动更新
1、应用升级（修改容器镜像）
kubectl set image deployment <deployment name> <containers name>=<image name>:<tags>
2、查看升级状态
kubectl rollout status deployment <deployment name>
3、查看历史版本
kubectl rollout history deployment <deployment name>
4、回滚到上一个版本
kubectl rollout undo deployment <deployment name>
5、回滚到指定版本
kubectl rollout undo deployment <deployment name> --to-revision=历史版本号
6、弹性伸缩（在线扩容）
kubectl scale deployment <deployment name> --replicas=期望副本数量
八、连接阿里云私有仓库
1、查看secret
kubectl get secret [-n 名称空间默认default]
默认只有一个
root@master:~# kubectl get secret
NAME TYPE DATA AGE
default-token-cx7df kubernetes.io/service-account-token 3 17d
2、创建一个secret
kubectl create secret docker-registry ali-secret --namespace=default --docker-server=registry.cn-beijing.aliyuncs.com --docker-username=username --docker-password=password --docker-email=dockerEmail
参数说明：
ali-secret：secret名字
--docker-serve：私有仓库地址
--docker-username：私有仓库登录用户名
--docker-password：私有仓库登录密码
--docker-email：登录邮箱（可选）
--namespace:指定命名空间 （可选）
3、再查看多一个
root@master:~# kubectl get secret
NAME TYPE DATA AGE
ali-secret kubernetes.io/dockerconfigjson 1 3m12s
default-token-cx7df kubernetes.io/service-account-token 3 17d
4、以yaml形式查看
kubectl get secret ali-secret -n default -o yaml
5、Deployment使用
apiVersion: apps/v1
kind: Deployment
metadata:
name: mydeployment
labels:
app: myapp
spec:
replicas: 1
selector:
matchLabels:
app: app
template:
metadata:
labels:
app: app
spec:
imagePullSecrets:
- name: ali-secret （使用刚才创建的secret）
hostNetwork: true
dnsPolicy: ClusterFirstWithHostNet
containers:
- name: app1
image: registry.cn-beijing.aliyuncs.com/xxx/xxx:[镜像版本号]
imagePullPolicy: IfNotPresent
ports:
- containerPort: 8880
注意
指定使用的secret
imagePullSecrets:
- name: ali-secret （使用刚才创建的secret）
指定使用镜像的全名称:版本号
image: registry.cn-beijing.aliyuncs.com/xxx/xxx:[镜像版本号]
6、进入容器
kubectl exec <pod名> -c <容器名> -it /bin/bash
7、查看pod详细信息
kubectl describe pod [pod名]