Kubeadm部署k8s集群

kubeadm部署k8s

1.创建Master节点

kubeadm init

2.将node节点添加到Master集群中

kubeadm join <Master节点的IP和端口>

Kubernetes部署环境要求

（1）一台或多台机器，操作系统CentOS 7.x-86_x64

（2）硬件配置：内存2GB或2G+，CPU 2核或CPU 2核+；

（3）集群内各个机器之间能相互通信；

（4）集群内各个机器可以访问外网，需要拉取镜像；

（5）禁止swap分区；

1.部署准备工作

小知识

如果是使用vmware创建的镜像，ip可能会变化，因此需要设置静态ip，文件有则修改，无则添加！之后重启即可

# 修改ifcfg-ens33文件
vi /etc/sysconfig/network-scripts/ifcfg-ens33

BOOTPROTO="static"		 # 设置静态地址 [设置dbcp吧，要不然没网QWQ]
IPADDR="192.168.226.132" # 设置固定的ip地址

1. 关闭防火墙

systemctl stop firewalld
systemctl disable firewalld

2. 关闭selinux

sed -i 's/enforcing/disabled/' /etc/selinux/config  #永久
setenforce 0  #临时

3. 关闭swap（k8s禁止虚拟内存以提高性能）

sed -ri 's/.*swap.*/#&/' /etc/fstab #永久
swapoff -a #临时

4. 修改主机名

cat >> /etc/hosts << EOF
192.168.85.132 k8s-master
192.168.85.130 k8s-node1
192.168.85.133 k8s-node2
EOF

5. 设置网桥参数

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

6. 时间同步

yum install ntpdate -y	#若是没有这个工具的需要下载
ntpdate time.windows.com

2.安装具体步骤

所有服务器节点安装 Docker/kubeadm/kubelet/kubectl

Kubernetes 默认容器运行环境是Docker，因此首先需要安装Docker；

0. 安装wget、vim

yum install wget -y
yum install vim -y

1. 安装docker

更新docker的yum源

wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo

查看docker版本

yum list docker-ce --showduplicates|sort -r

#显示版本
[root@localhost ~]# yum list docker-ce --showduplicates | sort -r
已加载插件：fastestmirror
已安装的软件包
可安装的软件包
 * updates: mirrors.huaweicloud.com
Loading mirror speeds from cached hostfile
 * extras: mirrors.nju.edu.cn
docker-ce.x86_64            3:20.10.9-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:20.10.9-3.el7                    @docker-ce-stable
docker-ce.x86_64            3:20.10.8-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:20.10.7-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:20.10.6-3.el7                    docker-ce-stable 
# 复制中间就可以了：3:20.10.9-3.el7  即 20.10.9

安装指定版本的docker

yum install docker-ce-20.10.9 -y

2. 配置国内镜像加速器

sudo vi /etc/docker/daemon.json

{
      "registry-mirrors" : ["https://q5bf287q.mirror.aliyuncs.com", "https://registry.docker-cn.com","http://hub-mirror.c.163.com"],
 	 "exec-opts": ["native.cgroupdriver=systemd"]
}

自动启动docker

systemctl enable docker.service

3. 添加k8s的阿里云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

4. 安装 kubeadm，kubelet 和 kubectl

yum install kubelet-1.23.6 kubeadm-1.23.6 kubectl-1.23.6 -y

卸载k8s

kubeadm reset -f
yum remove -y kubelet-1.26.0 kubeadm-1.26.0 kubectl-1.26.0
rm -rf /etc/cni /etc/kubernetes /var/lib/dockershim /var/lib/etcd /var/lib/kubelet /var/run/kubernetes ~/.kube/*

自动启动

systemctl enable kubelet.service

5. 查询是否安装成功

yum list installed | grep kubelet
yum list installed | grep kubeadm
yum list installed | grep kubectl

Kubelet：运行在cluster所有节点上，负责启动POD和容器；

Kubeadm：用于初始化cluster的一个工具；

Kubectl：kubectl是kubenetes命令行工具，通过kubectl可以部署和管理应用，查看各种资源，创建，删除和更新组件

6. 部署Kubernetes Master主节点

# kubeadm init --apiserver-advertise-address=192.168.85.129 --image-repository registry.aliyuncs.com/google_containers --kubernetes-version v1.26.0 --service-cidr=10.96.0.0/12 --pod-network-cidr=10.244.0.0/16 # 版本太高，不适合docker了

kubeadm init --apiserver-advertise-address=192.168.85.132 --image-repository registry.aliyuncs.com/google_containers --kubernetes-version v1.23.6 --service-cidr=10.96.0.0/16 --pod-network-cidr=10.244.0.0/16

安装成功：

[root@k8s-master system]# kubeadm init --apiserver-advertise-address=192.168.85.132 --image-repository registry.aliyuncs.com/google_containers --kubernetes-version v1.23.6 --service-cidr=10.96.0.0/16 --pod-network-cidr=10.244.0.0/16
[init] Using Kubernetes version: v1.23.6
[preflight] Running pre-flight checks
[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'
[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-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.85.132]
[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-master localhost] and IPs [192.168.85.132 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8s-master localhost] and IPs [192.168.85.132 127.0.0.1 ::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
[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
[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"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[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 11.012407 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.23" in namespace kube-system with the configuration for the kubelets in the cluster
NOTE: The "kubelet-config-1.23" naming of the kubelet ConfigMap is deprecated. Once the UnversionedKubeletConfigMap feature gate graduates to Beta the default name will become just "kubelet-config". Kubeadm upgrade will handle this transition transparently.
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node k8s-master as control-plane by adding the labels: [node-role.kubernetes.io/master(deprecated) node-role.kubernetes.io/control-plane node.kubernetes.io/exclude-from-external-load-balancers]
[mark-control-plane] Marking the node k8s-master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: z7srgx.xy1cf18s9saqkiij
[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

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
# 接下来要执行的命令
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/

Then you can join any number of worker nodes by running the following on each as root:
# 添加节点的方式
kubeadm join 192.168.85.132:6443 --token z7srgx.xy1cf18s9saqkiij \
	--discovery-token-ca-cert-hash sha256:69acc269317fe7baf0838909e1a4b9514dc73520d99c94af31941f53c261b58a 

[root@k8s-master system]# docker images
REPOSITORY                                                        TAG       IMAGE ID       CREATED         SIZE
registry.aliyuncs.com/google_containers/kube-apiserver            v1.23.6   8fa62c12256d   8 months ago    135MB
registry.aliyuncs.com/google_containers/kube-controller-manager   v1.23.6   df7b72818ad2   8 months ago    125MB
registry.aliyuncs.com/google_containers/kube-scheduler            v1.23.6   595f327f224a   8 months ago    53.5MB
registry.aliyuncs.com/google_containers/kube-proxy                v1.23.6   4c0375452406   8 months ago    112MB
registry.aliyuncs.com/google_containers/etcd                      3.5.1-0   25f8c7f3da61   14 months ago   293MB
registry.aliyuncs.com/google_containers/coredns                   v1.8.6    a4ca41631cc7   15 months ago   46.8MB
registry.aliyuncs.com/google_containers/pause                     3.6       6270bb605e12   16 months ago   683kB
[root@k8s-master system]# 

可能出现的错误：

kubelet版本过高，v1.24版本后kubernetes放弃docker了,根据上面安装1.23.6版本的

错误1：

[ERROR CRI]: container runtime is not running: output: E0104 17:29:26.251535    1676 remote_runtime.go:948] "Status from runtime service failed" err="rpc error: code = Unimplemented desc = unknown service runtime.v1alpha2.RuntimeService"
time="2023-01-04T17:29:26+08:00" level=fatal msg="getting status of runtime: rpc error: code = Unimplemented desc = unknown service runtime.v1alpha2.RuntimeService"
, error: exit status 1

解决方案：

rm /etc/containerd/config.toml
systemctl restart containerd
kubeadm init	#重新部署节点

出错之后，运行kubeadm reset然后再次kubeadm init。

kubeadm reset

错误2：

[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get "http://localhost:10248/healthz": dial tcp [::1]:10248: connect: connection refused.
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get "http://localhost:10248/healthz": dial tcp [::1]:10248: connect: connection refused.
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get "http://localhost:10248/healthz": dial tcp [::1]:10248: connect: connection refused.
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get "http://localhost:10248/healthz": dial tcp [::1]:10248: connect: connection refused.
[kubelet-check] It seems like the kubelet isn't running or healthy.

解决

#修改kubelet的启动配置文件 /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf ，在ExecStart上添加 
--feature-gates SupportPodPidsLimit=false --feature-gates SupportNodePidsLimit=false
#修改后执行
systemctl daemon-reload && systemctl restart kubelet。

错误3：

[init] Using Kubernetes version: v1.26.0
[preflight] Running pre-flight checks
error execution phase preflight: [preflight] Some fatal errors occurred:
	[ERROR CRI]: container runtime is not running: output: E0105 14:58:45.055862    8435 remote_runtime.go:948] "Status from runtime service failed" err="rpc error: code = Unimplemented desc = unknown service runtime.v1alpha2.RuntimeService"
time="2023-01-05T14:58:45+08:00" level=fatal msg="getting status of runtime: rpc error: code = Unimplemented desc = unknown service runtime.v1alpha2.RuntimeService"
, error: exit status 1
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`
To see the stack trace of this error execute with --v=5 or higher

解决：

rm -rf /etc/containerd/config.toml
systemctl restart containerd

正常显示：

[init] Using Kubernetes version: v1.26.0
[preflight] Running pre-flight checks
[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'

7. 在Master上执行上一步提示的命令

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

查询节点命令

kubectl get nodes

显示：

[root@k8s-master system]# kubectl get nodes
NAME         STATUS     ROLES                  AGE     VERSION
k8s-master   NotReady   control-plane,master   9m37s   v1.23.6

8. 将node节点添加到master中，在node机器中执行此命令即可【该命令是第6步中初始化节点时出现的】

kubeadm join 192.168.85.132:6443 --token z7srgx.xy1cf18s9saqkiij \
	--discovery-token-ca-cert-hash sha256:69acc269317fe7baf0838909e1a4b9514dc73520d99c94af31941f53c261b58a 

运行结果：

[root@k8s-node1 ~]# kubeadm join 192.168.85.132:6443 --token z7srgx.xy1cf18s9saqkiij \
> --discovery-token-ca-cert-hash sha256:69acc269317fe7baf0838909e1a4b9514dc73520d99c94af31941f53c261b58a 
[preflight] Running pre-flight checks
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...

This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.

Run 'kubectl get nodes' on the control-plane to see this node join the cluster.

9. 部署网络插件 用于节点之间的项目通讯

wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

有时候可能会下载失败

[root@k8s-master docker]# wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
--2023-01-05 16:28:08--  https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
正在解析主机 raw.githubusercontent.com (raw.githubusercontent.com)... 0.0.0.0, ::
正在连接 raw.githubusercontent.com (raw.githubusercontent.com)|0.0.0.0|:443... 失败：拒绝连接。
正在连接 raw.githubusercontent.com (raw.githubusercontent.com)|::|:443... 失败：拒绝连接。

就手动配置，直接打开连接复制就可以

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', '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/v1
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/v1
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
        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
        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

应用kube-flannel.yml文件

kubectl apply -f kube-flannel.yml

运行结果

[root@k8s-master k8s]# kubectl apply -f kube-flannel.yml
namespace/kube-flannel created
clusterrole.rbac.authorization.k8s.io/flannel configured
clusterrolebinding.rbac.authorization.k8s.io/flannel configured
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds created

查看运行时的容器pod【一个pod里面可以运行多个docker容器】

kubectl get pods -n kube-system

启动可能需要等一会

# 成功之后
[root@k8s-master k8s]# kubectl get nodes
NAME         STATUS     ROLES                  AGE   VERSION
k8s-master   Ready      control-plane,master   52m   v1.23.6
k8s-node1    Ready   	<none>                 30m   v1.23.6
k8s-node2    Ready      <none>                 24m   v1.23.6

至此部署完成！