实践Kubernetes

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Kubernetes is an open-source system for automating deployment, scaling, and management of containerized applications.

概念

  • master

  • node

  • pod

label

  • service

label selector

  • container

pause

安装

版本

CentOS 7.6

docker-ce 19.03.9-3.el7

Kubernetes 1.19.16-0

calico 3.20

关闭防火墙

systemctl disable firewalld

systemctl stop firewalld

关闭swap

swapoff -a

vi /etc/fstab，删除swap挂载

建议在主机上禁用 SELinux （修改文件／etc/sysconfig/selinux, SELINUX=enforcing 修改为 SELIN口(=中sabled)

修改主机名

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hostnamectl set-hostname k8s-master

/etc/hosts

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# step 1: 安装必要的一些系统工具
sudo yum install -y yum-utils device-mapper-persistent-data lvm2
# Step 2: 添加软件源信息
sudo yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
# Step 3
sudo sed -i 's+download.docker.com+mirrors.aliyun.com/docker-ce+' /etc/yum.repos.d/docker-ce.repo
# Step 4: 更新并安装Docker-CE
sudo yum makecache fast
# Step 5：安装指定版本的docker-ce
yum -y install docker-ce-19.03.9-3.el7

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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=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

yum install -y kubelet-1.19.16-0 kubeadm-1.19.16-0 kubectl-1.19.16-0

echo 1 > /proc/sys/net/bridge/bridge-nf-call-iptables

cat > /etc/docker/daemon.json «EOF { “exec-opts”: [“native.cgroupdriver=systemd”], “log-driver”: “json-file”, “log-opts”: { “max-size”: “100m” }, “storage-driver”: “overlay2”, “storage-opts”: [ “overlay2.override_kernel_check=true” ] } EOF

rm -rf /var/lib/etcd/

kubeadm init phase preflight

kubeadm init

kubeadm config print init-defaults

kubeadm config print join-defaults

kubeadm config images list

kubeadm config images pull

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

kubeadm init –image-repository registry.aliyuncs.com/google_containers

export KUBECONFIG=/etc/kubernetes/admin.conf

kubeadm join 192.168.1.231:6443 –token ot1cwn.jcjdue03ud93or6r
–discovery-token-ca-cert-hash sha256:81abfd322b69dcccef74381214fa54f52205dfca34a1a0bb8e253d805a433926

kubectl -n kube-system get configmap

kubectl get nodes

安装CNI网络插件

kubectl apply -f “https://docs.projectcalico.org/archive/v3.20/manifests/calico.yaml”

kubectl get pods –all-namespaces

kubectl apply -f mysql-deploy.yaml

mysql-deploy.yaml

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apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: mysql
  name: mysql
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mysql
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
      - image: mysql:5.7
        name: mysql
        ports:
        - containerPort: 3306
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: "123456"

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$ kubectl get deploy
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
mysql   1/1     1            1           24h
myweb   2/2     2            2           24h

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$ kubectl get pods
NAME                     READY   STATUS    RESTARTS   AGE
mysql-596b96985c-p9l52   1/1     Running   0          23h
myweb-7d75cf577c-qzbl8   1/1     Running   0          23h
myweb-7d75cf577c-x9mgd   1/1     Running   0          23h

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$ docker ps |grep mysql
b78afdeb29c5   mysql                                               "docker-entrypoint.s…"   24 hours ago   Up 24 hours             k8s_mysql_mysql-596b96985c-p9l52_default_077df04c-d430-49c9-8070-db9010e00ec6_0
227547a3c1e2   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 24 hours ago   Up 24 hours             k8s_POD_mysql-596b96985c-p9l52_default_077df04c-d430-49c9-8070-db9010e00ec6_0

kubectl create -f mysql-svc.yaml

mysql-svc.yaml

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apiVersion: v1
kind: Service
metadata:
  name: mysql
spec:
  ports:
    - port: 3306
  selector:
    app: mysql

kubectl get svc mysql

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$ kubectl get svc
NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE
kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP          28h
mysql        ClusterIP   10.104.218.155   <none>        3306/TCP         23h
myweb        NodePort    10.106.209.221   <none>        8080:30001/TCP   23h

注意修改mysql的地址

kubectl apply -f myweb-deploy.yaml

myweb-deploy.yaml

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apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: myweb
  name: myweb
spec:
  replicas: 2
  selector:
    matchLabels:
      app: myweb
  template:
    metadata:
      labels:
        app: myweb
    spec:
      containers:
      - image: kubeguide/tomcat-app:v1
        name: myweb
        ports:
        - containerPort: 8080
        env:
        - name: MYSQL_SERVICE_HOST
          value: 10.104.218.155

kubectl create -f myweb-svc.yaml

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apiVersion: v1
kind: Service
metadata:
  name: myweb
spec:
  type: NodePort
  ports:
    - port: 8080
      nodePort: 30001
  selector:
    app: myweb

kubectl get deployments.apps

kubectl edit deployment/myweb -o yaml –save-config

kubectl get svc myweb

http://192.168.1.232:30001/demo/

相关书籍

《Kubernetes权威指南：从Docker到Kubernetes实践全接触》

《Kubernetes权威指南——企业级容器云实战》

相关网站

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