安装

K8S

Ubuntu 18.04安装

准备

  • 一台master，两个node

  • 镜像仓库（harbor或公有仓库）

关闭swap分区

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

安装kubeadm

sudo apt-get update && sudo  apt-get install -y apt-transport-https
curl https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg  |  sudo apt-key add -
sudo bash -c 'cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main
EOF'
sudo apt-get update && sudo apt-get install -y kubelet kubeadm kubectl

容器Runtime

使用Docker

sudo apt install -y docker docker.io && sudo systemctl enable docker
# 改为systemd
sudo bash -c ' cat > /etc/docker/daemon.json <<EOF
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  }
}
EOF'
sudo systemctl restart docker

使用Contained

  • 相比docker更纯粹，更专注于容器runtime

    https://kubernetes.io/docs/setup/production-environment/container-runtimes/

    ```

    prepare

    sudo bash -c 'cat > /etc/modules-load.d/containerd.conf <<EOF

    br_netfilter

    EOF'

    sudo bash -c 'cat > /etc/sysctl.d/99-kubernetes-cri.conf <<EOF

    net.bridge.bridge-nf-call-iptables = 1

    net.ipv4.ip_forward = 1

    net.bridge.bridge-nf-call-ip6tables = 1

    EOF'

    sudo sysctl --system

sudo apt-get update && sudo apt-get install -y containerd

Configure containerd

sudo mkdir -p /etc/containerd sudo bash -c 'containerd config default > /etc/containerd/config.toml' sudo sed -i 's/systemd_cgroup = false/systemd_cgroup = true/' /etc/containerd/config.toml

Restart containerd

sudo systemctl restart containerd

容器信息查看方法: `sudo crictl -r unix:///run/containerd/containerd.sock pods`

### 集群初始化
参数`control-plane-endpoint`为apiserver的外部负载均衡入口，创建高可用集群时需要  
需要预先准备好，无准备可去掉此参数  
`upload-certs`可一键作为master加入集群中，低版本参数可能时`--experimental-upload-certs`  
使用`upload-certs`时，需妥善保存`kubeadm init`完成后生成的作为master加入的join命令，其可访问集群内部数据  
使用`kubeadm init phase upload-certs --upload-certs`可刷新join命令

sudo kubeadm init --apiserver-advertise-address=192.168.76.139 --control-plane-endpoint=192.168.76.139:6443 --upload-certs --image-repository registry.aliyuncs.com/google_containers --pod-network-cidr=10.244.0.0/16

#### 配置kubectl

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

#### 初始化flannel
`kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml`

#### 加入集群
在master节点运行 `kubeadm token create --print-join-command`  
在node节点运行上面的输出来作为node节点  
作为master加入时，依赖上方介绍的`upload-certs`和`control-plane-endpoint`参数  
3主2从集群: `kubectl get nodes -o wide` 
>NAME    STATUS   ROLES    AGE     VERSION   INTERNAL-IP      EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION       CONTAINER-RUNTIME
>main    Ready    master   23m     v1.18.3   192.168.76.139   <none>        Ubuntu 18.04.4 LTS   4.15.0-106-generic   docker://19.3.6
>main2   Ready    master   7m9s    v1.18.3   192.168.76.136   <none>        Ubuntu 18.04.4 LTS   4.15.0-106-generic   docker://19.3.6
>main3   Ready    master   17m     v1.18.3   192.168.76.140   <none>        Ubuntu 18.04.4 LTS   4.15.0-106-generic   docker://19.3.6
>vm2     Ready    <none>   43s     v1.18.3   192.168.76.137   <none>        Ubuntu 18.04.4 LTS   4.15.0-106-generic   docker://19.3.6
>vm3     Ready    <none>   7m55s   v1.18.3   192.168.76.138   <none>        Ubuntu 18.04.4 LTS   4.15.0-91-generic    docker://19.3.6


### 创建Pod

echo 'apiVersion: apps/v1 kind: Deployment metadata: name: nginx-deployment labels: app: nginx spec: replicas: 2 selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers:

  • name: nginx

    image: nginx

    ports:

    • containerPort: 80

      ' | kubectl apply -f -

      ```

kubectl get pods 输出如下:

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES nginx-deployment-d46f5678b-4xk6v 1/1 Running 0 63s 10.244.2.4 vm3 nginx-deployment-d46f5678b-t54mx 1/1 Running 0 63s 10.244.1.5 vm2 删除任意一个pod，k8s都会再创建一个，保持数量为2

kubectl get deployment 输出如下:

NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR nginx-deployment 2/2 2 2 92s nginx nginx app=nginx

扩容: kubectl scale --replicas=3 deployment nginx-deployment

创建Service

echo 'apiVersion: v1
kind: Service
metadata:
  name: nginx-svc
spec:
  ports:
  - port: 8880
    targetPort: 80
    protocol: TCP
  selector:
    app: nginx' | kubectl apply -f -

查看结果 kubectl get svc -o wide

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR kubernetes ClusterIP 10.96.0.1 443/TCP 22h nginx-svc ClusterIP 10.99.243.241 8880/TCP 54s app=nginx

转为NodePort模式:

echo 'apiVersion: v1
kind: Service
metadata:
  name: nginx-svc
spec:
  type: NodePort
  ports:
  - port: 8880
    targetPort: 80
    protocol: TCP
  selector:
    app: nginx' | kubectl apply -f -

查看结果 kubectl get svc -o wide

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR kubernetes ClusterIP 10.96.0.1 443/TCP 22h nginx-svc NodePort 10.99.243.241 8880:30548/TCP 10m app=nginx NodePort模式使所有节点都暴露了一个端口，可使用节点ip加暴露的端口来访问服务

使用Ingress来暴露服务

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