Kubernetes 安裝部署之kubeadm
阿新 • • 發佈：2022-03-30
Kubernetes 基本邏輯
Master
k8s叢集控制節點，對叢集進行排程管理，接受叢集外使用者去叢集操作請求；
Master Node 由 API Server、Scheduler、ClusterState Store（ETCD 資料庫）和 Controller MangerServer 所組成；
Nodes
叢集工作節點，執行使用者業務應用容器；
Nodes節點也叫Worker Node，包含kubelet、kube proxy 和 Pod（Container Runtime）；
Kubernetes環境搭建方式
部署 Kubernetes 環境（叢集）主要有多種方式：
（1）minikube
minikube可以在本地執行Kubernetes的工具，minikube可以在個人計算機（包括Windows，macOS和Linux PC）上執行一個單節點Kubernetes叢集，以便您可以試用Kubernetes或進行日常開發工作；
https://kubernetes.io/docs/tutorials/hello-minikube/
（2）kind
Kind和minikube類似的工具，讓你在本地計算機上執行Kubernetes，此工具需要安裝並配置Docker；
https://kind.sigs.k8s.io/
（3）kubeadm
Kubeadm是一個K8s部署工具，提供kubeadm init 和 kubeadm join兩個操作命令，可以快速部署一個Kubernetes叢集；
官方地址：
https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/
（4）二進位制包
從Github下載發行版的二進位制包，手動部署安裝每個元件，組成Kubernetes叢集，步驟比較繁瑣，但是能讓你對各個元件有更清晰的認識；
（5）yum安裝
通過yum安裝Kubernetes的每個元件，組成Kubernetes叢集，不過yum源裡面的k8s版本已經比較老了，所以這種方式用得也比較少了；
（6）第三方工具
有一些大神封裝了一些工具，利用這些工具進行k8s環境的安裝；
（7）花錢購買
直接購買類似阿里雲這樣的公有云平臺k8s，一鍵搞定；
Kubeadm部署Kubernetes
kubeadm是官方社群推出的一個用於快速部署 kubernetes 叢集的工具，這個工具能通過兩條指令完成一個kubernetes叢集的部署；
1、建立一個Master節點：
kubeadm init
2、將Node節點加入到Master叢集中：
$ kubeadm join <Master節點的IP和埠 --token {...} --discovery-token-ca-cert-hash {...}>
Kubernetes部署環境要求
（1）一臺或多臺機器，作業系統CentOS 7.x-86_x64
（2）硬體配置：記憶體2GB或2G+，CPU 2核或CPU 2核+；
（3）叢集內各個機器之間能相互通訊；
（4）叢集內各個機器可以訪問外網，需要拉取映象；
（5）禁止swap分割槽；
Kubernetes部署環境準備
# 關閉防火牆
systemctl stop firewalld
systemctl disable firewalld
# 關閉selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config #永久
setenforce 0 #臨時
# 關閉swap（k8s禁止虛擬記憶體以提高效能） 避免pod 失控偷跑現象
sed -ri 's/.*swap.*/#&/' /etc/fstab #永久
swapoff -a #臨時
# 在master新增hosts
cat >> /etc/hosts << EOF
192.168.1.4 k8smaster
192.168.1.5 k8snode
192.168.1.6 k8snode2
EOF
# 設定網橋引數
cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system #生效
# 時間同步
yum install ntpdate -y
ntpdate time.windows.com
Kubernetes安裝具體步驟
所有伺服器節點安裝 Docker/kubeadm/kubelet/kubectl
Kubernetes 預設容器執行環境是Docker，因此首先需要安裝Docker；
（1）安裝 Docker
更新docker的yum源
yum install wget -y
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
安裝指定版本的docker：yum install docker-ce-19.03.13 -y
yum install docker -y （這個安裝的Docker版本偏舊） 1.13.x
配置加速器加速下載 （https://cr.console.aliyun.com/）
/etc/docker/daemon.json
{
"registry-mirrors": ["https://registry.docker-cn.com"]
}
https://gg3gwnry.mirror.aliyuncs.com
然後執行：systemctl enable docker.service
不然會提示警告；
那麼接下來需要搭建：kubeadm、kubelet、kubectl
（2）新增k8s的阿里雲YUM源
cat > /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
到時候下載k8s的相關元件才能找到下載源；
（2）安裝 kubeadm，kubelet 和 kubectlyum install kubelet-1.19.4 kubeadm-1.19.4 kubectl-1.19.4 -y
然後執行：systemctl enable kubelet.service
不然會提示警告；
檢視有沒有安裝：
yum list installed | grep kubelet
yum list installed | grep kubeadm
yum list installed | grep kubectl
檢視安裝的版本： kubelet --version
Kubelet：執行在cluster所有節點上，負責啟動POD和容器；
Kubeadm：用於初始化cluster的一個工具；
Kubectl：kubectl是kubenetes命令列工具，通過kubectl可以部署和管理應用，檢視各種資源，建立，刪除和更新元件；
此時應該重啟一下centos；
（3）部署Kubernetes Master主節點kubeadm init --apiserver-advertise-address=192.168.1.4 --image-repository registry.aliyuncs.com/google_containers --kubernetes-version v1.19.4 --service-cidr=10.96.0.0/12 --pod-network-cidr=10.244.0.0/16
此命令在master機器上執行；
說明：
service-cidr 的選取不能和PodCIDR及本機網路有重疊或者衝突，一般可以選擇一個本機網路和PodCIDR都沒有用到的私網地址段，比如PODCIDR使用10.244.0.0/16, 那麼service cidr可以選擇10.96.0.0/12，網路無重疊衝突即可；-pod-network-cidr 網路段和第三方網路外掛預設網段一致比如：kube-flannel 預設網路段是10.244.0.0這裡保持一致否則後面要修改。
接下來在master機器上執行：
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
kubectl get nodes
接下來把node節點加入Kubernetes master中，在Node機器上執行；
向叢集新增新節點，執行的命令就是kubeadm init最後輸出的kubeadm join命令：
kubeadm join 192.168.1.4:6443 --token pxopo0.nw11lzd6kfcj69jj --discovery-token-ca-cert-hash sha256:409f67eeb4b55ba8e5c480776d0fcbf02287e423d9c4340163e2a0ab8c5d915e
部署網路外掛
下載kube-flannel.yml檔案wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
不過國內網路好像下載不了了後面提供yaml檔案，當然其他網路外掛也是可以的
應用kube-flannel.yml檔案得到執行時容器kubectl apply -f kube-flannel.yml （在master機器上執行）
然後檢視節點狀態： kubectl get nodes （在master機器上執行）需要等一會兒，然後節點就就緒了；
至此我們的k8s環境就搭建好了；
檢視執行時容器pod （一個pod裡面運行了多個docker容器）kubectl get pods -n kube-system
Kubernetes部署“容器化應用”
Docker應用-->在docker裡面部署一個java程式（springboot）
在Kubernetes叢集中部署一個Nginx：
kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --port=80 --type=NodePort
kubectl get pod,svc
訪問地址：http://NodeIP:Port
在Kubernetes叢集中部署一個Tomcat：
kubectl create deployment tomcat --image=tomcat
kubectl expose deployment tomcat --port=8080 --type=NodePort
訪問地址：http://NodeIP:Port
轉摘：https://www.cnblogs.com/tangy1/p/14925216.html
K8s部署微服務（springboot程式）
1、專案打包（jar、war）-->可以採用一些工具git、maven、jenkins
2、製作Dockerfile檔案，生成映象；
3、kubectl create deployment nginx --image= 你的映象
4、你的springboot就部署好了，是以docker容器的方式執行在pod裡面的；
kube-flannel.yml程式碼
cat <<EOF > kube-flannel.yml
---
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
EOF