Workload（工作负载）

  • Deployments：无状态化
  • StatefulSets：有状态化
  • DaemonSets：守护进程

    一、环境信息

    Hyper-V 部署的麒麟 V10 SP1 最小化安装
主机 配置 地址
Master 2C4G 192.168.254.101
Node01 2C4G 192.168.254.102
Node02 2C4G 192.168.254.103

二、组件清单

1.主节点

  • docker：也可以用其他容器运行时
  • kubectl：集群命令行交互工具
  • kubeadm：集群初始化工具

    2.工作节点

  • docker：也可以用其他容器运行时
  • kubelet：管理 Pod 和容器，确保他们健康稳定运行
  • kube-proxy：网络代理，负责网络相关的工作

    三、创建集群

    https://jimmysong.io/kubernetes-handbook/practice/install-kubernetes-on-centos.html

    1.初始化系统

    1.1.设置主机名

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    hostnamectl set-hostname devops
    hostnamectl set-hostname master
    hostnamectl set-hostname node01
    hostnamectl set-hostname node02

    1.2.修改 hosts

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    cat >> /etc/hosts <<EOF
    192.168.254.100 devops
    192.168.254.101 master
    192.168.254.102 node01
    192.168.254.103 node02
    EOF

    cat /etc/hosts

    1.3.关闭 SELinux

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    setenforce 0
    sed -i --follow-symlinks 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/sysconfig/selinux

    1.4.关闭防火墙

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    systemctl stop firewalld
    systemctl disable firewalld

    1.5.关闭 SWAP

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    #临时关闭
    swapoff -a
    #永久关闭
    vi /etc/fstab
    #注释掉以下字段
    /dev/mapper/centos-swap swap swap defaults 0 0

    1.6.时间同步

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    yum install -y ntpdate
    crontab -e
    */5 * * * * ntpdate ntp.aliyun.com
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    #安装 epel-release 源，需要 RedHat 系
    yum install epel-release
    yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
    yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm

    2.添加安装源

    国内镜像站
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https://developer.aliyun.com/mirror/docker-ce/
https://mirrors.tuna.tsinghua.edu.cn/

2.1.Docker

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cat << EOF > /etc/yum.repos.d/docker-ce.repo
[docker-ce-stable]
name=Docker CE Stable
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/x86_64/stable
enabled=1
gpgcheck=0
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg
EOF

2.2.Kubenetes

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cat << EOF > /etc/yum.repos.d/kubernetes.repo
[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

3.安装组件

v1.24 版本及以上的 Kubernetes 放弃了原生 Docker 容器运行时的支持

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yum list docker-ce.x86_64 --showduplicates | sort -r
yum install docker-ce-20.10.10
systemctl enable docker && systemctl start docker
docker info | grep Cgroup

yum list kube* --showduplicates | sort -r
yum install kubelet-1.23.6 kubectl-1.23.6 kubeadm-1.23.6

3.1.修改 Docker 配置

设置为 systemd，确保服务器节点在资源紧张的情况更加稳定

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cat > /etc/docker/daemon.json << EOF
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "registry-mirrors": ["https://ustc-edu-cn.mirror.aliyuncs.com"]
}
EOF
systemctl daemon-reload & systemctl restart docker
docker info | grep Cgroup

#Kubernetes 官方推荐 Docker 等使用 systemd 作为 cgroupdriver，否则 kubelet 启动不了
systemctl enable kubelet && systemctl start kubelet

3.2.kubectl 命令补全

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yum install -y bash-completion
source /usr/share/bash-completion/bash_completion
source <(kubectl completion bash)
echo "source <(kubectl completion bash)" >> ~/.bashrc

4.初始化集群

PS.如果没有关闭 SWAP，可以通过以下配置忽略 SWAP 报错

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vi /etc/sysconfig/kubelet
KUBELET_EXTRA_ARGS="--fail-swap-on=false"

4.1.Master 节点

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#初始化集群控制台 control-plane，失败了可以用 kubeadm reset 重置
kubeadm init --kubernetes-version v1.23.6 \
--apiserver-advertise-address=192.168.254.101 \
--image-repository registry.aliyuncs.com/google_containers \
--service-cidr=10.96.0.0/12 \
--pod-network-cidr=10.244.0.0/16 \
--ignore-preflight-errors=Swap

参数说明：

  • —kubernetes-version # 指定 Kubernetes 版本
  • —apiserver-advertise-address # 指定 Master 主机的 IP
  • —image-repository # 指定阿里云镜像仓库地址
  • —service-cidr # 指定 service 网络段
  • —pod-network-cidr # 指定 pod 网络段
  • —ignore-preflight-errors=Swap # 忽略 Swap 报错信息，按需选择
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[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 [kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local master] and IPs [10.96.0.1 192.168.254.101]
[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 [localhost master] and IPs [192.168.254.101 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [localhost master] and IPs [192.168.254.101 127.0.0.1 ::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 22.503431 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 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 master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: qwrpqf.tb10u9boslu6mzoj
[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

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:

kubeadm join 192.168.254.101:6443 --token qwrpqf.tb10u9boslu6mzoj \
        --discovery-token-ca-cert-hash sha256:14f18211150be68eb24efdc0053a6fd9587da1b77ea0050074f0bb87544926a0

后续修改网段

然后等待拉取镜像，初始化完成以后按提示运行

image.png

记住 kubeadm jion 192.168.1.101:6443 … 命令，以便后续 Node 节点加入集群

  • 配置 kubectl
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#复制授权文件，以便其他节点 kubectl 可以有权限访问集群
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
  • 添加网络组件

否则 NotReady

Flannel 是一个专门为 K8s 定制的网络解决方案，主要解决 Pod 跨主机通信问题

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wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
kubectl apply -f kube-flannel.yml
kubectl delete -f kube-flanneld.yaml

image.png

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# 验证 flannel 网络插件是否部署成功（Running 即为成功）
kubectl get pods -n kube-system | grep flannel

Calico 包括原生 VXLAN 功能，无需 Flannel

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curl https://raw.githubusercontent.com/projectcalico/calico/v3.24.5/manifests/canal.yaml -O
kubectl apply -f canal.yaml

4.2.Node 节点

  • 节点加入集群
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kubeadm join 192.168.1.101:6443 \
--token 7wor0d.7i31zm9hw330ay97 \
--discovery-token-ca-cert-hash sha256:70970addce82343177ba403997644a2a38d7b8058724c5c22b8b1d5018c05560

image.png

  • 配置 kubectl
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#复制授权文件，以便其他节点 kubectl 可以有权限访问集群
mkdir -p $HOME/.kube
#通过 cat /etc/kubernetes/admin.conf 拷贝 Master 节点内容
vi $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

4.3.验证集群

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kubectl cluster-info
kubectl version --short=true

查看集群客户端和服务端程序版本信息

image.png

查看集群信息

image.png

四、管理集群

1.Web 界面

1.1. Dashboard

Angular + Go、单集群、K8s 资源管理

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wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.7.0/aio/deploy/recommended.yaml
mv recommended.yaml kubernetes-dashboard.yaml
kubectl apply -f kubernetes-dashboard.yaml

1.2. Kuboard

Vue、多集群、K8s 资源管理

1.3. Kubevious

React、多集群、K8s 资源管理、全资源检索、资源回滚

1.4. KubeSphere

React + Go、多集群、K8s 资源管理、CLI 安装、升级、KubeSphere Mini 入侵、应用商店

1.5. KubeOperator

Vue + Go、多集群、K8s 资源管理、Web 安装、升级 K8s

2.命令行

2.1.kubectl

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kubectl get node
kubectl get service -A
kubectl get service -n kube-system
kubectl get pod -A
kubectl get pod -n kube-system

2.2.自动补全

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yum install -y bash-completion
source /usr/share/bash-completion/bash_completion
source <(kubectl completion bash)
echo "source <(kubectl completion bash)" >> ~/.bashrc

2.3.YAML

基本语法

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apiVersion: v1 #必选，API 版本号
kind: Deployment #必选，Pod 类型：
metadata: #必选，元数据
  name: nginx-deployment #必选，符合 RFC1035 规范的 Pod 名称
  namespace: web #可选，不指定默认为 default，Pod 所在命名空间
spec: #必选，用于定义详细信息
  selector: #标签选择器
    matchLabels:
      app: nginx
  replicas: 2 #必选，Pod 副本数量
  template:
    metadata: #必选，元数据
      labels: #可选，标签选择器，一般用于 Service Selector
        app: nginx
    spec: #必选，用于定义详细信息
      containers: #必选，定义容器
      - name: nginx
        image: nginx:1.14.2
        ports:
        - containerPort: 80

3.管理应用

3.1.启动应用

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kubectl create
kubectl run
kubectl run demo --image=nginx:1.7.9 --replicas=2

3.2.访问应用

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kubectl exec -it pod_name /bin/bash
kubectl expose
kubectl edit services

3.3.扩容应用

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3.4.升级应用

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五、其他方式

1.Sealos

1.1.安装 sealos

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wget https://github.com/labring/sealos/releases/download/v4.0.0/sealos_4.0.0_linux_amd64.tar.gz
tar zxvf sealos_4.0.0_linux_amd64.tar.gz sealos && chmod +x sealos && mv sealos /usr/bin

1.2.创建集群

  • 在线安装
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sealos run labring/kubernetes:v1.25.0 labring/calico:v3.24.1 \
     -m 192.168.254.101 \
     -n 192.168.254.102,192.168.254.103 \
     -u app -p '密码'
  • 离线安装

离线环境只需要提前导入镜像，其它步骤与在线安装一致。

首先在有网络的环境中 save 安装包：

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sealos pull labring/kubernetes:v1.25.0
sealos save -o kubernetes.tar labring/kubernetes:v1.25.0

拷贝 kubernetes.tar 到离线环境, 使用 load 命令导入镜像即可：

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剩下的安装方式与在线安装一致。

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sealos images # 查看集群镜像是否导入成功
sealos run kuberentes:v1.25.0 --single # 单机安装，集群安装同理

2.Kubesphere