k8s学习笔记一（搭建&部署helloworld应用）

kubernetes

目录

• kubernetes
  • 虚拟机创建三个节点
  • k8s install
  • 部署hello world 应用
  • issue 汇总
    • node 一直处理NotReady状态
  • 重启系统后虚拟机的网络不通

---

虚拟机创建三个节点

这里略过.

• 网络模式用的hostonly
• 系统ubuntu 20.04
  

k8s install

set -x#根据规划设置主机名(在3台机上分别运行)hostnamectl set-hostname master01hostnamectl set-hostname node01hostnamectl set-hostname node02#关闭防火墙ufw disable#关闭swapswapoff -a && sed -ri 's/.*swap.*/#&/' /etc/fstab#安装 dockersudo apt-get install -y dockersudo apt-get install -y docker.io docker --version systemctl start dockerapt-get install -y apt-transport-httpsapt-get install -y curl# kubeadm init 默认会去google拉镜像，所以换了阿里的源，前面docker是系统默认的.curl https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | apt-key add - cat <<EOF >/etc/apt/sources.list.d/kubernetes.listdeb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial mainEOFapt-get update# master上运行apt-get install -y kubelet kubeadm kubectl# node上运行apt-get install -y kubelet kubeadmapt-get install -y ethtoolapt-get install -y socatapt-get install -y conntrack# checkkubeadm version# 配置docker cgroupdriver (与kubelet要一致)cat <<EOF >/etc/docker/daemon.json{"exec-opts": ["native.cgroupdriver=systemd"]}EOFsystemctl restart dockersystemctl start kubeletexport KUBECONFIG=/etc/kubernetes/admin.conf# master 上运行kubeadm init --image-repository registry.aliyuncs.com/google_containers --pod-network-cidr=10.244.0.0/16#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/##Then you can join any number of worker nodes by running the following on each as root:##kubeadm join 192.168.137.6:6443 --token vzcxza.bhcs335r92677g3i \#	--discovery-token-ca-cert-hash sha256:72b820c8f2dd7606ddbf6a155fadb57e0f266c15bb39c7f41de61cc605f6f962 # kubeadm init 通过给的 kubeadm join 将node 加入master 节点kubeadm join 192.168.137.6:6443 --token vzcxza.bhcs335r92677g3i \	--discovery-token-ca-cert-hash sha256:72b820c8f2dd7606ddbf6a155fadb57e0f266c15bb39c7f41de61cc605f6f962# K8S在kubeadm init以后查询kubeadm join# kubeadm token create --print-join-commandset +x

到这1个master节点2个node节点的k8s就搭好了
可以用kubect get xxx 检查状态，(我这里刚搭完还是 notReady 状态，检查后是网络插件没装，遇到的话可以参考后面issue汇总里面)

root@master01:~/k8s# kubectl get nodes -ANAME       STATUS   ROLES                  AGE     VERSIONmaster01   Ready    control-plane,master   4d17h   v1.23.5node01     Ready    <none>                 2d      v1.23.5node02     Ready    <none>                 2d      v1.23.5

部署hello world 应用

• app ：

package mainimport (	"net/http"	"flag"	log "github.com/sirupsen/logrus"	"github.com/gin-gonic/gin")func entry(c *gin.Context) {	c.String(http.StatusOK, "hello !")}func main() {	flag.Parse()	var (	)	log.Info("hello serv start ...")	engine := gin.Default()	engine.GET("/entry", entry)	engine.Run("0.0.0.0:8868")}

• dockerfile

FROM golang:1.17.2-stretchENV GOPROXY=http://goproxy.ioWORKDIR $GOPATH/src/ADD ./bin $GOPATH/src/binADD ./source $GOPATH/src/RUN go env -w GOSUMDB=offWORKDIR $GOPATH/src/RUN go build -o /usr/local/bin/engineCMD ["/usr/local/bin/engine"]

• yml
  很久前玩minikube 的镜像： ailumiyana/minikube-hello:latest， 以前就放在docker hub了，app 就是上面的go代码，有需要自取，但这里建议开启docker代理，不然下载很慢或者可能都下不下来

apiVersion: apps/v1kind: Deploymentmetadata:  name: hello-minikubesspec:  selector:    matchLabels:      app: myweb  replicas: 2  template:    metadata:      labels:        app: myweb    spec:      containers:        - name: hello-minikubes          image: ailumiyana/minikube-hello:latest          ports:            - containerPort: 8868              protocol: TCP---apiVersion: v1kind: Servicemetadata:  name: mywebspec:  type: NodePort  ports:    - port: 8868      targetPort: 8868      nodePort: 31314  selector:    app: myweb

kubectl apply -f hello.yml

F5几下，检查两个节点，好像都有流量，还不知道什么策略，慢慢研究~

今天先到这~

issue 汇总

node 一直处理NotReady状态

• kubectl describe node node01
  检查到notready 状态 原因:
• untime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized

好像是没网络插件，搜索尝试手动添加 flannel 镜像和 cni 配置 后解决

docker pull quay.io/coreos/flannel:v0.11.0-amd64mkdir -p /etc/cni/net.d/cat <<EOF> /etc/cni/net.d/10-flannel.conf{"name":"cbr0","type":"flannel","delegate": {"isDefaultGateway": true}}EOFmkdir /usr/share/oci-umount/oci-umount.d -pmkdir /run/flannel/cat <<EOF> /run/flannel/subnet.envFLANNEL_NETWORK=172.100.0.0/16FLANNEL_SUBNET=172.100.1.0/24FLANNEL_MTU=1450FLANNEL_IPMASQ=trueEOF

https://raw.githubusercontent.com/coreos/flannel/v0.11.0/Documentation/kube-flannel.yml
然后这个yml 里面beta版本貌似是过期的，改成v1 后好了

重启系统后虚拟机的网络不通

这个也是个坑，最后在网络连接里面，重新关闭开启vmnet1的网络共享后好了.