kubernetes 1.15 快速部署体验

kubeadm 安装k8s 1.15

主机分配

• 192.168.235.129 ：k8s-master

• 192.168.235.130 ：k8s-node-1

• 192.168.235.131 : k8s-node-2

各节点主机设置

以下操作在各节点操作

• 关闭防火墙

systemctl stop firewalld
systemctl disable firewalld

• 关闭selinux

sed -i 's/enforcing/disabled/' /etc/selinux/config
setenforce 0

• 关闭sawp

swapoff -a   #临时
vim /etc/fstab #将开机挂载列表中的swap分区删除永久禁用

• 将桥接的IPv4流量传递到iptables的链

cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF

sysctl --system # 执行生效

• 所有节点安装Docker

systemctl enable docker && systemctl start docker
docker --version
Docker version 19.03.4

所有节点安装kubeadm/kubelet/kubectl/kubectl

• 添加阿里云的k8s YUM源

cat > /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

安装kubeadm,kubelet,kubectl

由于版本更新频繁，这里指定版本号部署:

yum install -y kubelet-1.15.0 kubeadm-1.15.0 kubectl-1.15.0

systemctl enable kubelet

部署kubernetes Master

在master（192.168.235.129）节点执行

kubeadm init \
--apiserver-advertise-address=192.168.235.129 \
--image-repository registry.aliyuncs.com/google_containers \
--kubernetes-version v1.15.0 \
--service-cidr=10.1.0.0/16 \
--pod-network-cidr=10.244.0.0/16

执行初始化后要等待一段时间，拉取镜像要花点时间

• --apiserver-advertise-address : 向集群通报api-server地址

• --image-repository ：集群所需的镜像，默认会从google镜像仓库拉取，被墙，这里要配置成阿里的镜像地址

• --kubernetes-version ：指定kubernetes版本

• --service-cidr=10.1.0.0/16 ：指定 service地址范围

• --pod-network-cidr ：指定容器的 IP范围

初始化完成后执行提示命令

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

并且可以看到生成的加入集群的验证指令：其他节点执行该指令就可以加入集群

kubeadm join 192.168.235.129:6443 --token ua1abl.k7qs6jsj96grfbto \
    --discovery-token-ca-cert-hash sha256:6f8cfd90f464df748d5db56e948860a61b0e727aea1893c72125fea171f84d59

此时master节点并未启动成功，它还需要kubernetes网络的加入

部署flannel网络组件

wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

确保能够访问到quay.io这个registery,通常有墙，如果无法下载可以先下载到本地

网络插件部署完成后查看master节点的核心组件状态：

[root@master ~]# kubectl get pods -n kube-system
NAME                             READY   STATUS    RESTARTS   AGE
coredns-bccdc95cf-p9frm          1/1     Running   0          114m
coredns-bccdc95cf-xlhkd          1/1     Running   0          114m
etcd-master                      1/1     Running   1          113m
kube-apiserver-master            1/1     Running   1          113m
kube-controller-manager-master   1/1     Running   1          113m
kube-flannel-ds-amd64-crrcq      1/1     Running   0          75s
kube-proxy-2cngx                 1/1     Running   1          114m
kube-scheduler-master            1/1     Running   1          113m
[root@master ~]# kubectl get nodes
NAME     STATUS   ROLES    AGE    VERSION
master   Ready    master   114m   v1.15.0

node节点加入集群

flannel网络插件是运行在集群各节点上的，因此每个节点都要下载该插件，在执行kubectl join时也会去下载该插件，如果无法现在，要提前下载到各个node节点 docker pull quay.io/coreos/flannel:v0.11.0-arm

将各node节点加入集群，使用上面master节点初始化后生成的指令

各node节点执行：

kubeadm join 192.168.235.129:6443 --token ua1abl.k7qs6jsj96grfbto \
    --discovery-token-ca-cert-hash sha256:6f8cfd90f464df748d5db56e948860a61b0e727aea1893c72125fea171f84d59

Run 'kubectl get nodes' on the control-plane to see this node join the cluster. 添加完成最后提示这信息说明已经加入了集群

node节点加入集群后，master节点任然需要下载依赖的网络组件，所以仍然需要等待一点时间，取决于网速快慢

• master节点查看集群状态

[root@master ~]# kubectl get pods -n kube-system
NAME                             READY   STATUS    RESTARTS   AGE
coredns-bccdc95cf-p9frm          1/1     Running   0          147m
coredns-bccdc95cf-xlhkd          1/1     Running   0          147m
etcd-master                      1/1     Running   1          146m
kube-apiserver-master            1/1     Running   1          146m
kube-controller-manager-master   1/1     Running   1          146m
kube-flannel-ds-amd64-bj8gn      1/1     Running   0          10m
kube-flannel-ds-amd64-crrcq      1/1     Running   0          34m
kube-flannel-ds-amd64-qq2fv      1/1     Running   0          9m59s
kube-proxy-2cngx                 1/1     Running   1          147m
kube-proxy-dncr6                 1/1     Running   0          9m59s
kube-proxy-l2vrt                 1/1     Running   0          10m
kube-scheduler-master            1/1     Running   1          146m

• 查看集群节点

[root@master ~]# kubectl get nodes
NAME         STATUS   ROLES    AGE    VERSION
k8s-node-1   Ready    <none>   14m    v1.15.0
k8s-node-2   Ready    <none>   13m    v1.15.0
master       Ready    master   151m   v1.15.0

至此，k8s集群部署完成

测试集群

在集群中添加一个pod，看是否正常

[root@master ~]# kubectl create deployment nginx --image=nginx
deployment.apps/nginx created
[root@master ~]# kubectl expose deployment nginx --port=80 --type=NodePort
service/nginx exposed

查看pod

[root@master ~]# kubectl get pod,svc
NAME                         READY   STATUS    RESTARTS   AGE
pod/nginx-554b9c67f9-wvnpr   1/1     Running   0          97s

NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)        AGE
service/kubernetes   ClusterIP   10.1.0.1     <none>        443/TCP        159m
service/nginx        NodePort    10.1.9.142   <none>        80:32632/TCP   48s

可以看到service暴露出来的随机端口是32632，那么访问http://192.168.235.129:32632/即可

使用Deployment创建pod资源

使用Deployment方式创建pod资源，并指定独立的Namespace，和service进行服务暴露，yaml文件内容如下：

apiVersion: v1
kind: Namespace
metadata:
  name: nginx
  namespace: nginx
  labels:
    app: nginx

---

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: nginx-server
  namespace: nginx
  labels:
    deploy: nginx
spec:
  replicas: 2
  selector:
    matchLabels:
      service: nginx
  template:
    metadata:
      name: nginx-service
      labels:
        service: nginx
    spec:
      containers:
      - name: nginx-service
        image: nginx:1.15
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80
          protocol: TCP


---

apiVersion: v1
kind: Service
metadata:
  name: nginx-svc
  namespace: nginx
  labels:
    svc: nginx
spec:
  selector:
    service: nginx
  ports:
  - port: 80
    targetPort: 80
    nodePort: 30001
  type: NodePort