.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=4 \\
--etcd-servers=http://192.168.8.201:2379 \\
--insecure-bind-address=0.0.0.0 \\
--insecure-port=8080 \\
--advertise-address=192.168.8.201 \\
--allow-privileged=true \\
--service-cluster-ip-range=10.10.10.0/24 \\
--service-node-port-range=30000-50000 \\
--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=4 \\
--master=127.0.0.1:8080 \\
--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=4 \\
--master=127.0.0.1:8080 \\
--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=4 \\
--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=4 \
--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.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节点验证时候有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=3
kubectl expose deployment nginx --port=88 --target-port=80 --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: 1
  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: 9090
          protocol: TCP
        args:
           - --apiserver-host=http://192.168.8.201:8080
        livenessProbe:
          httpGet:
            path: /
            port: 9090
          initialDelaySeconds: 30
          timeoutSeconds: 30

---

kind: Service
apiVersion: v1
metadata:
  labels:
    app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  type: NodePort
  ports:
  - port: 80
    targetPort: 9090
  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