集群(cluster)创建工具比较

  • 参考

  • 工具

    • MiniKube

      • 单机，学习

    • Kind

      • 一个 container 一个 node

    • Kubeadm

      • 要求高

    • K3S

      • 不使用 docker, 减配版 k8s

network addons

国内安装

  • 教程
  • 更全面教程

  • 难点

    • 安装 docker

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         curl -fsSL https://get.docker.com -o get-docker.sh
   sudo sh get-docker.sh

    • 安装 kubeadm kubectl kubelet

      • 添加源

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          #在 /etc/apt/source.list 添加
  deb https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial main

  # 或者
  echo "deb https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list

      • 解决 找不到 public key

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          sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys <PUBKEY>

  sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys FEEA9169307EA071 8B57C5C2836F4BEB

      • 安装 kubeadm kubectl kubelet

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          sudo apt -y install  kubelet kubeadm kubectl

      • bash completion

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          kubectl completion bash >/etc/bash_completion.d/kubectl
  echo 'alias k=kubectl' >>~/.bashrc
  echo 'complete -F __start_kubectl k' >>~/.bashrc


  kubeadm completion bash >/etc/bash_completion.d/kubeadm

  • k8s docker 镜像

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      sudo kubeadm config images pull --image-repository=registry.aliyuncs.com/google_containers

  sudo kubeadm init --control-plane-endpoint=inside --pod-network-cidr=10.11.0.0/16 --image-repository registry.aliyuncs.com/google_containers

    • 下载失败的 image, 从 docker hub 上令找，在 docker tag 处理

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        # 另找到的源
  sudo docker pull coredns/coredns:1.8.0

  # 重命名
  sudo docker tag  coredns/coredns:1.8.0 registry.aliyuncs.com/google_containers/coredns/coredns:v1.8.0

  • 总步骤

    • 工具安装

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        # install docker
  sudo apt install curl -y
  curl -fsSL https://get.docker.com -o get-docker.sh
  sudo sh ./get-docker.sh
  rm ./get-docker.sh
  sudo usermod -aG docker $USER


  # 安装 kubeadm kubelet kubectl
  echo "deb https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list && \
  sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys FEEA9169307EA071 8B57C5C2836F4BEB && \
  sudo apt update && \
  sudo apt -y install  kubelet kubeadm kubectl && \
  sudo kubectl completion bash |sudo tee /etc/bash_completion.d/kubectl && \
  echo 'alias k=kubectl' >>~/.bashrc && \
  echo 'complete -F __start_kubectl k' >>~/.bashrc && \
  \
  sudo kubeadm completion bash |sudo tee /etc/bash_completion.d/kubeadm && \
  \
  sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab && \
  sudo swapoff -a


  sudo modprobe overlay
  sudo modprobe br_netfilter

  sudo tee /etc/sysctl.d/kubernetes.conf<<EOF
  net.bridge.bridge-nf-call-ip6tables = 1
  net.bridge.bridge-nf-call-iptables = 1
  net.ipv4.ip_forward = 1
  EOF

  sudo sysctl --system

    • kubeadm init

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        # images download
  sudo kubeadm config images pull --image-repository=registry.aliyuncs.com/google_containers
  sudo kubeadm config images pull

  sudo docker pull coredns/coredns:1.8.0
  sudo docker tag  coredns/coredns:1.8.0 registry.aliyuncs.com/google_containers/coredns/coredns:v1.8.0

  # 部署， 注意 cidr 选择
  sudo kubeadm init --control-plane-endpoint=<...your master hostname> --pod-network-cidr=10.11.0.0/16 --image-repository registry.aliyuncs.com/google_containers
  sudo kubeadm init --control-plane-endpoint=kmaster --pod-network-cidr=10.11.0.0/16 --image-repository registry.aliyuncs.com/google_containers
  sudo kubeadm init --control-plane-endpoint=kmaster --pod-network-cidr=10.11.0.0/16
  • 成功结果

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/

You can now join any number of control-plane nodes by copying certificate authorities and service account keys on each node and then running the following as root:

kubeadm join inside:6443 –token 1ghtrm.yv2ndw8552tupu7w \ –discovery-token-ca-cert-hash sha256:6c85a03f5d91312b30078999143999d96c29aeef6f53851170acaaa5a6a31c82 \ –control-plane

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join inside:6443 –token 1ghtrm.yv2ndw8552tupu7w \ –discovery-token-ca-cert-hash sha256:6c85a03f5d91312b30078999143999d96c29aeef6f53851170acaaa5a6a31c82

deployment(Controller)

  • 两种方式

    • kubectl run
    • yaml 配置文件， kubectl apply -f your.yaml

部署信息查询

  • kubectl rollout status

    • 成功与否

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        kubectl rollout status deployment <your-deployment>

  • 简述信息

    • kubectl get deployment

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        kubectl get deployment <your-deployment>

  • 详细信息

    • kubectl describe deployment

  • 展示创建的 ReplicaSet

    • kubectl get replicaset

  • 部署的 Pod

    • kubectl get pods

部署后操作

  • 修改 image

    • kubectl set image deployment

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        kubectl set image deployment  example-deployment nginx=nginx:latest --record

  • 查看 部署过程

    • kubectl rollout history deployment

回滚

  • 查看版本历史

    • kubectl rollout history deployment

  • 查看具体版本

    • kubectl rollout history deployment ---revision=<version>

  • 回退版本

    • kubectl rollout undo deployment --to-revision=<version>

修改 replicas 数量

kubectl scale --replicas=<new number> deployment <your-deployment>

暂停 与 重新启动

  • 暂停

    • kubectl rollout deploy <your-deployment>

  • 启动

    • kubectl rollout resume deploy <your-deployment>

Service 服务

类型

  • ClusterIP: 默认类型

    • 只能在 Cluster 内部访问

  • NodePort

    • 暴露在每一个 Node 的固定端口上
    • 外部可以访问
    • 访问形式：<NodeIP>:<NodePort>

  • LoadBalancer

    • 云服务商提供，负载均衡

  • ExternalName

    • 域名形式
    • eg: foo.bar.example.com

辨析

yaml 配置文件

  1. Deployment

    • 需要有 selector 字段，下面包含 matchLabels 字段，再接 labels

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        apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: httpd-demo
    labels:
      app: httpd

  spec:
    replicas: 3
    selector:            #----------- 注意
      matchLabels:
        app: httpd
    template:
      metadata:
        labels:
          app: httpd
      spec:
        containers:
          - name: httpd
            image: httpd:latest
            ports:
              - containerPort: 80

  2. Service

    • selector 字段，下面不需要 matchLabels，直接跟 labels

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        apiVersion: v1
  kind: Service
  metadata:
    name: httpd-demo
  spec:
    type: NodePort
    selector:   # ----------------- 注意
      app: httpd

    ports:
      - protocol: TCP
        port: 8080
        targetPort: 80
        nodePort: 30036

问题

kubeadm join –v=5

  • token 不识别问题

  • 方法：生成新的 token

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      # 生成token 错误解决方法
  sudo cp ./.kube/ /root/ -r

  sudo kubeadm token create --print-join-command


  # 再次，worker 机器
  sudo kubeadm join ...

Label

  • 命令 kubectl label

service

port 解说

  • 参考

  • targetPort :: docker export

    • docker 内部真实的最初的 功能提供端口

  • port :: cluster port

    • docker 映射到 cluster 中的端口

  • nodePort :: 节点 端口

    • Node 对外部主机 暴露的可以访问的端口

  • 对应映射关系

    • docker port –> cluaster targetPort –> 节点 nodePort

  • 数据包转发流程

    1. 发送到主机 Node –> nodePort
    2. 主机发送给 –> Service 监听端口 targetPort
    3. targetPort 再转发给 –> docker 容器 port

辨析

  • deployment 中 也有一个 port
  • deployment port 需要等于 service targetPort

  • 注意

    • 如果 deployment port != service targetPort

      • 如果 targetPort 确实是 docker 内部应用提供服务的端口，无影响

命令方式创建

  • 命令

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      kubectl create service nodeport httpd-demo --node-port 30080 --tcp 8080:80

  kubectl create service <servie-type> <service-name> --node-port <Your port> --tcp <targetPort>:<port(cluster port)>

    • 注意

      • 这样创建一个与 service-name 相关的 selector

        • 即： selector: app=service-name