.net core i上 K8S(一)集群搭建

1.前言

　　以前搭建集群都是使用nginx反向代理，但现在我们有了更好的选择——K8S。我不打算一上来就讲K8S的知识点，因为知识点还是比较多，我打算先从搭建K8S集群讲起，我也是在搭建集群的过程中熟悉了K8S的一些概念，希望对大家有所帮助。K8S集群的搭建难度适中，网上有很多搭建k8s的教程，我搭建的过程中或多或少遇到一些问题，现在就把我总结完的教程给大家总结一下。这里主要讲通过二进制包安装K8S

2.集群组件介绍

节点

组件

master

192.168.8.201

etcd：存储集群节点信息

kubectl：管理集群组件，通过kubectl控制集群

kube-controller-manage：监控节点是否健康，不健康则自动修复至健康状态

kube-scheduler：负责为kube-controller-manage创建的pod选择合适的节点，将节点信息写入etcd

node

192.168.8.202

kube-proxy：service与pod通信

kubelet：kube-scheduler将节点数据存入etcd后，kubelet获取到并按规则创建pod

docker

3.etcd安装

yum install etcd –y

vi /etc/etcd/etcd.conf

修改etcd.conf内容

ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"

启动

systemctl start etcd

systemctl enable etcd

4.下载k8s安装包

打开github中k8s地址，选择一个版本的安装包

点击CHANGELOG-1.13.md，在master节点上安装server包，node节点上安装node包

5.master节点安装server

tar zxvf kubernetes-server-linux-amd64.tar.gz　　　　　　#解压

mkdir -p /opt/kubernetes/{bin,cfg}　　　　　　　　　　　　#创建文件夹

mv kubernetes/server/bin/{kube-apiserver,kube-scheduler,kube-controller-manager,kubectl} /opt/kubernetes/bin　　　　#移动文件到上一步的文件夹
chmod +x /opt/kubernetes/bin/*

5.1配置apiserver

cat <<EOF >/opt/kubernetes/cfg/kube-apiserver

KUBE_APISERVER_OPTS="--logtostderr=true \\

--v= \\

--etcd-servers=http://192.168.8.201:2379 \\

--insecure-bind-address=0.0.0.0 \\

--insecure-port= \\

--advertise-address=192.168.8.201 \\

--allow-privileged=true \\

--service-cluster-ip-range=10.10.10.0/ \\

--service-node-port-range=- \\

--admission-control=NamespaceLifecycle,LimitRanger,SecurityContextDeny,ResourceQuota"

EOF

cat <<EOF >/usr/lib/systemd/system/kube-apiserver.service

[Unit]

Description=Kubernetes API Server

Documentation=https://github.com/kubernetes/kubernetes

[Service]

EnvironmentFile=-/opt/kubernetes/cfg/kube-apiserver

ExecStart=/opt/kubernetes/bin/kube-apiserver \$KUBE_APISERVER_OPTS

Restart=on-failure

[Install]

WantedBy=multi-user.target

EOF

5.2配置kube-controller-manager

cat <<EOF >/opt/kubernetes/cfg/kube-controller-manager

KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=true \\

--v= \\

--master=127.0.0.1: \\

--leader-elect=true \\

--address=127.0.0.1"

EOF

cat <<EOF >/usr/lib/systemd/system/kube-controller-manager.service

[Unit]

Description=Kubernetes Controller Manager

Documentation=https://github.com/kubernetes/kubernetes

[Service]

EnvironmentFile=-/opt/kubernetes/cfg/kube-controller-manager

ExecStart=/opt/kubernetes/bin/kube-controller-manager \$KUBE_CONTROLLER_MANAGER_OPTS

Restart=on-failure

[Install]

WantedBy=multi-user.target

EOF

5.3配置kube-scheduler

cat <<EOF >/opt/kubernetes/cfg/kube-scheduler

KUBE_SCHEDULER_OPTS="--logtostderr=true \\

--v= \\

--master=127.0.0.1: \\

--leader-elect"

EOF

cat <<EOF >/usr/lib/systemd/system/kube-scheduler.service

[Unit]

Description=Kubernetes Scheduler

Documentation=https://github.com/kubernetes/kubernetes

[Service]

EnvironmentFile=-/opt/kubernetes/cfg/kube-scheduler

ExecStart=/opt/kubernetes/bin/kube-scheduler \$KUBE_SCHEDULER_OPTS

Restart=on-failure

[Install]

WantedBy=multi-user.target

EOF

5.4运行kube-api与kube-controller-manager与kube-scheduler

vim ku.sh    #创建一个脚本，内容如下

#!/bin/bash

systemctl daemon-reload

systemctl enable kube-apiserver

systemctl restart kube-apiserver

systemctl enable kube-controller-manager

systemctl restart kube-controller-manager

systemctl enable kube-scheduler

systemctl restart kube-scheduler

执行以上脚本

chmod +x *.sh　　　　#给权限

./ku.sh　　　　#运行

5.5将kubectl配置到环境变量，便于执行

echo "export PATH=$PATH:/opt/kubernetes/bin" >> /etc/profile

source /etc/profile

至此server安装成功，可通过命令查看相关进程是否启动成功

ps -ef |grep kube

启动失败可通过以下命令查看信息

journalctl -u kube-apiserver

6.安装node节点

6.1docker安装

sudo yum install -y yum-utils device-mapper-persistent-data lvm2

sudo yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

sudo yum makecache fast

sudo yum -y install docker-ce

sudo systemctl start docker

6.2解压node.zip包

tar zxvf kubernetes-node-linux-amd64.tar.gz

mkdir -p /opt/kubernetes/{bin,cfg}

mv kubernetes/node/bin/{kubelet,kube-proxy} /opt/kubernetes/bin/

　chmod +x /opt/kubernetes/bin/*

6.3创建配置文件

vim /opt/kubernetes/cfg/kubelet.kubeconfig

apiVersion: v1

kind: Config

clusters:

- cluster:

    server: http://192.168.8.201:8080

  name: kubernetes

contexts:

- context:

    cluster: kubernetes

  name: default-context

current-context: default-context

vim /opt/kubernetes/cfg/kube-proxy.kubeconfig

apiVersion: v1

kind: Config

clusters:

- cluster:

    server: http://192.168.8.201:8080

  name: kubernetes

contexts:

- context:

    cluster: kubernetes

  name: default-context

current-context: default-context

cat <<EOF >/opt/kubernetes/cfg/kubelet

KUBELET_OPTS="--logtostderr=true \\

--v= \\

--address=192.168.8.202 \\

--hostname-override=192.168.8.202 \\

--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \\

--allow-privileged=true \\

--cluster-dns=10.10.10.2 \\

--cluster-domain=cluster.local \\

--fail-swap-on=false \\

--pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0"

EOF

cat <<EOF >/usr/lib/systemd/system/kubelet.service

[Unit]

Description=Kubernetes Kubelet

After=docker.service

Requires=docker.service

[Service]

EnvironmentFile=-/opt/kubernetes/cfg/kubelet

ExecStart=/opt/kubernetes/bin/kubelet \$KUBELET_OPTS

Restart=on-failure

KillMode=process

[Install]

WantedBy=multi-user.target

EOF

cat <<EOF >/opt/kubernetes/cfg/kube-proxy

KUBE_PROXY_OPTS="--logtostderr=true \

--v= \

--hostname-override=192.168.8.202 \

--kubeconfig=/opt/kubernetes/cfg/kube-proxy.kubeconfig"

EOF

cat <<EOF >/usr/lib/systemd/system/kube-proxy.service

[Unit]

Description=Kubernetes Proxy

After=network.target

[Service]

EnvironmentFile=-/opt/kubernetes/cfg/kube-proxy

ExecStart=/opt/kubernetes/bin/kube-proxy \$KUBE_PROXY_OPTS

Restart=on-failure

[Install]

WantedBy=multi-user.target

EOF

6.4启动kube-proxy与kubelet

vim ku.sh

#!/bin/bash

systemctl daemon-reload

systemctl enable kubelet

systemctl restart kubelet

systemctl enable kube-proxy

systemctl restart kube-proxy

至此node安装完成，查看是否安装成功

失败则查看日志

journalctl -u kubelet

7.master节点验证是否有node节点

查看集群健康状态

至此master与node安装成功

8.启动一个nginx示例

kubectl run nginx --image=nginx --replicas=

kubectl expose deployment nginx --port= --target-port= --type=NodePort

验证

浏览器访问

9.安装dashbord

vim kube.yaml

apiVersion: extensions/v1beta1

kind: Deployment

metadata:

  labels:

    app: kubernetes-dashboard

  name: kubernetes-dashboard

  namespace: kube-system

spec:

  replicas:

  selector:

    matchLabels:

      app: kubernetes-dashboard

  template:

    metadata:

      labels:

        app: kubernetes-dashboard

      annotations:

        scheduler.alpha.kubernetes.io/tolerations: |

          [

            {

              "key": "dedicated",

              "operator": "Equal",

              "value": "master",

              "effect": "NoSchedule"

            }

          ]

    spec:

      containers:

      - name: kubernetes-dashboard

        image: registry.cn-hangzhou.aliyuncs.com/google_containers/kubernetes-dashboard-amd64:v1.7.0

        imagePullPolicy: Always

        ports:

        - containerPort:

          protocol: TCP

        args:

           - --apiserver-host=http://192.168.8.201:8080

        livenessProbe:

          httpGet:

            path: /

            port:

          initialDelaySeconds:

          timeoutSeconds: 

---

kind: Service

apiVersion: v1

metadata:

  labels:

    app: kubernetes-dashboard

  name: kubernetes-dashboard

  namespace: kube-system

spec:

  type: NodePort

  ports:

  - port:

    targetPort:

  selector:

    app: kubernetes-dashboard

创建

kubectl create -f kube.yaml

查看pod

查看端口

访问bord

至此集群搭建完成