参考资料:
- kubernetes官网英文版
- kubernetes官网中文版
环境、工具
阿里云学生机ECS、Ubuntu、docker、kubectl1.15.4、kubelet1.15.4、kubeadm1.15.4、
安装kubeadm、kubectl、kubelet
配置软件源
默认apt软件源里没有这几个软件，需要添加谷歌官方的软件源。但又由于官方提供的源无法访问，需要改为阿里的源
curl -s https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | apt-key add -
cat </etc/apt/sources.list.d/kubernetes.list
deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main
EOF
apt-get update 命令说明：
1.通过下载工具下载位于https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg的deb软件包密钥，然后通过"apt-key"命令添加密钥
2.通过cat把源deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main写入到"/etc/apt/sources.list.d/kubernetes.list"
*此处下载工具使用curl，若未安装，先执行如下命令安装。"apt-transport-https"工具允许apt通过https来下载软件，可以不用安装这个，只装curl
apt-get update && apt-get install -y apt-transport-https curl完成以上步骤，可通过"apt-key list"命令看到类似如下的密钥信息:
查看"/etc/apt/sources.list.d/kubernetes.list",如下:
选择软件版本
kubeadm、kubectl、kubelet三者的版本要一致，否则可能会部署失败，小版本号不同倒也不会出什么问题，不过尽量安装一致的版本。记住kubelet的版本不可以超过API server的版本。例如1.8.0的API server可以适配 1.7.0的kubelet，反之就不行了。
可以通过"apt-cache madison"命令来查看可供安装的软件的版本号
例：
apt-cache madison kubeadm kubelet kubectl开始安装
这里安装的版本是"1.15.4-00"，别忘了后面的"-00"。
需要注意，安装kubeadm的时候，会自动安装kubectl、kubelet和cri-tool，安装kubelet时会自动安装kubernetes-cni，如下：
然而这并不是一件好事，仔细看会发现自动安装的kubectl和kubelet是最新版本，与kubeadm版本不一致。。。
所以应该先安装kubectl和kubelet，命令如下：
apt-get install kubectl=1.15.4-00 kubelet=1.15.4-00 kubeadm=1.15.4-00如果不想让软件自动更新，可以输入:
apt-mark hold kubeadm kubectl kubelet允许更新：
apt-mark unhold kubeadm kubectl kubelet部署前准备
关闭防火墙
在ubuntu下，可以使用"ufw"管理防火墙。
查看防火墙状态：
ufw status 禁用防火墙:
ufw diable启用防火墙:
ufw enable关闭selinux
阿里云ecs没有selinux，在此不作验证，网上找到的方法如下:
- 修改/etc/selinux/config文件中设置SELINUX=disabled，然后重启服务器
- 使用setenforce
- setenforce 1 设为enforcing模式
- setenforce 0 设为permissive模式
关闭swap
- 临时修改，重启复原
- 关闭
swapoff -a- 开启
swapon -a - 永久修改，重启生效
- 把根目录文件系统设为可读写
sudo mount -n -o remount,rw /- 修改"/etc/fstab"文件，在"/swapfile"一行前加#禁用并保存退出重启服务器
开启kubelet服务
systemctl enable kubelet修改Docker的cgroup-driver
编辑"/etc/docker/daemon.json"
添加如下信息:
"exec-opts": ["native.cgroupdriver=systemd"]注意，需要在前面的键值对后用“,”逗号隔开，再添加新的配置项，否则配置文件会解析失败。
修改完后保存，重新载入配置文件，重启docker
systemctl daemon-reload
systemctl restart docker配置iptables转发规则
iptables -P FORWARD ACCEPT开始部署
kubeadm init --kubernetes-version=v1.15.4 --ignore-preflight-errors=NumCPU --pod-network-cidr=10.244.0.0/16 --image-repository registry.aliyuncs.com/google_containers参数说明:
"kubernetes-version"：指定k8s的版本，对于不同版本k8s，kubeadm会去拉取不同版本的镜像。
"--pod-network-cidr": 指定使用"cidr"方式给pod分配IP，参数的数值必须跟后面网络插件的配置文件一致。后面用到的网络插件为flannel，flannel配置文件中默认的数值是“10.244.0.0/16”
"--image-repository": 指定镜像仓库，kubeadm默认的仓库地址没法访问，需要指定为阿里云的地址——"registry.aliyuncs.com/google_containers"
- "--ignore-preflight-errors"：kubeadm在初始化之前，会执行“preflight”(预检)，当条件不满足时会报错并停止初始化进程，但是有些报错并不会影响集群的初始化，因此可以指定该参数忽略特定的错误。阿里云学生机cpu只有单核，而k8s要求双核及以上，所以需要指定参数"--ignore-preflight-errors=NumCPU"。
该参数的用法如下：
--ignore-preflight-errors=
--ignore-preflight-errors=NumCPU查看部署状态
当看到上述信息就表示集群Master节点初始化成功，在同一网络下的机器上同样地安装kuneadm、kubelet并配置好环境之后，即可通过"kubeadm join"命令连接到Master节点使集群成为多节点集群:
kubeadm join 192.168.1.73:6443 --token gkp9ws.rv2guafeusg7k746 \
--discovery-token-ca-cert-hash sha256:4578b17cd7198a66438b3d49bfb878093073df23cf6c5c7ac56b3e05d2e7aec0该token默认有效期为24小时，可通过"kubeadm token create --print-join-command"命令创建新token，并打印连接命令:
初始化成功后，在master节点上可以通过kubectl命令来查看集群上资源的状态，但是kubectl在访问API Server时需要认证，认证信息在"/etc/kubernetes/admin.conf"文件里，需要把文件拷贝到"$HOME/.kube/config/"下，否则会出现"The connection to the server localhost:8080 was refused"这样的错误。
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config这句话在初始化成功后会打印出来，直接拷贝。
也可以直接添加环境变量：
export KUBECONFIG=/etc/kubernetes/admin.conf可以把这条变量添加到"/etc/profile"，然后"source /etc/profile"。
配置好后，通过"kubectl get node"即可看到集群的所有节点状态:
可以看到当前节点处于"NotReady"状态，通过"kubectl describe node
在"Ready"一行，"status"为"false"，"message"提示"Runtime newtwork not ready"，意思是网络插件未准备好，所以此时应该给集群安装网络插件。
安装网络插件
网络插件有很多种，此处选择"flannel"，flannel的安装比较简单，直接指定配置文件，用"kubectl"安装即可。配置文件如下:
---
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']
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-amd64
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: beta.kubernetes.io/os
operator: In
values:
- linux
- key: beta.kubernetes.io/arch
operator: In
values:
- amd64
hostNetwork: true
tolerations:
- operator: Exists
effect: NoSchedule
serviceAccountName: flannel
initContainers:
- name: install-cni
image: quay.io/coreos/flannel:v0.11.0-amd64
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:v0.11.0-amd64
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"]
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
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: kube-flannel-ds-arm64
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: beta.kubernetes.io/os
operator: In
values:
- linux
- key: beta.kubernetes.io/arch
operator: In
values:
- arm64
hostNetwork: true
tolerations:
- operator: Exists
effect: NoSchedule
serviceAccountName: flannel
initContainers:
- name: install-cni
image: quay.io/coreos/flannel:v0.11.0-arm64
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:v0.11.0-arm64
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"]
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
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: kube-flannel-ds-arm
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: beta.kubernetes.io/os
operator: In
values:
- linux
- key: beta.kubernetes.io/arch
operator: In
values:
- arm
hostNetwork: true
tolerations:
- operator: Exists
effect: NoSchedule
serviceAccountName: flannel
initContainers:
- name: install-cni
image: quay.io/coreos/flannel:v0.11.0-arm
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:v0.11.0-arm
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"]
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
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: kube-flannel-ds-ppc64le
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: beta.kubernetes.io/os
operator: In
values:
- linux
- key: beta.kubernetes.io/arch
operator: In
values:
- ppc64le
hostNetwork: true
tolerations:
- operator: Exists
effect: NoSchedule
serviceAccountName: flannel
initContainers:
- name: install-cni
image: quay.io/coreos/flannel:v0.11.0-ppc64le
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:v0.11.0-ppc64le
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"]
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
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: kube-flannel-ds-s390x
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: beta.kubernetes.io/os
operator: In
values:
- linux
- key: beta.kubernetes.io/arch
operator: In
values:
- s390x
hostNetwork: true
tolerations:
- operator: Exists
effect: NoSchedule
serviceAccountName: flannel
initContainers:
- name: install-cni
image: quay.io/coreos/flannel:v0.11.0-s390x
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:v0.11.0-s390x
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"]
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
128行的network数值应与"kubeadm"初始化时指定的"--pod-network-cidr"一致，该值表示给pod分配ip时的ip前缀。
创建好配置文件后，通过"kubeclt"安装flannel:
kubectl create -f 把
测试
处理taint
默认情况下，master节点会被打上一个叫"NoSchedule"的Taint(污点)，可以通过"kubectl describe"看到:
这个taint使得master节点不能被调度，也就是说master节点不能部署应用，由于现在搭建的是单节点集群，当前节点既充当master又得充当worker，所以需要把这个taint去掉:
kubectl taint node - kubectl taint node yo node-role.kubernetes.io/master:NoSchedule-注意别忘了taint后面的横杠"-"，"-"表示“减号”，即把taint去掉。如果不加横杠，表示加上taint。
运行nginx:
docker pull nginx
kubectl run nginx --image=nginx稍等片刻nginx就部署好了，可以通过"kubectl get pods --all-namespaces"查看，或者直接访问"curl localhost:80"。
排错工具
kubectl
kubectl get
"kubectl get"可以列出集群环境中的某类资源，对于k8s，几乎所有内容都是“资源”，如Node、Pod、Service等，只要把"
如查看节点资源:
kubectl get node
对于pod等其它的资源，kubectl的用法会有些许不同。k8s使用"namespace"来对集群中的资源进行分组管理，可以把"namespace"当做“分组的名称”，也可以把"namespace"当做k8s集群中的"集群"，不同"namespace"的资源在逻辑上彼此隔离，以此提高安全性，提高管理效率。用kubeectl查看这些个资源时，需要用"-n"来指定"namespace"，如：
kubectl get pod -n kube-system
还可以用"--all-namespaces"来查看所有"namespaces"下的资源:
kubectl get pod --all-namespaces
kubectl describe
对于处于异常状态的资源，可以使用该命令查看其详细信息，只要把
如:
kubectl describe pod -n kubernetes-dashboard kubernetes-dashboard-6b855d4584-9sgsk然后就可以看到该pod的事件信息:
docker ps -a
该命令可以查看当前所有docker容器，"-a"表示所有容器，当不加该参数时，显示的则是正在运行的容器。由于要查看的是k8s相关的容器，以此可以使用管道命令和"grep"对显示结果进行筛选:
docker ps -a | grep kube对于处于"Exited"状态的异常容器，使用"docker logs
docker logs 37443d902aee此处"37443d902aee"是我机器上"kubernetes-dashboard"的容器id。
友情链接
- Kubernetes最佳实践之：命名空间（Namespace）
- 部署k8s的图形化管理平台kubernetes-dashboard
- 解决阿里云ECS下kubeadm部署k8s无法指定公网IP