使用kubeadm搭建kubenetes集群部署Nginx

梦里梦外; 2023-01-22 15:46 5阅读 0赞

在搭建集群时候，对于硬件要求必须至少为2个CPU,关闭防火墙、SWAP、SELINUX、配置hosts，接下来搭建3个节点的集群，一个主节点两个工作节点，搭建后发布一个Nginx应用。

### 1 准备环境 ###

# 关闭防火墙 如果节点加入集群时超时，可能是防火墙未被关闭
    systemctl stop firewalld
    systemctl disable firewalld
    
    # 关闭selinux
    sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
    setenforce 0  # 临时
    
    # 关闭swap
    swapoff -a  # 临时
    sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久
    
    # 根据规划设置主机名（自定义） 主节点k8smaster 工作节点k8snode1、k8snode2
    hostnamectl set-hostname <hostname>
    
    # 在master添加hosts
    cat >> /etc/hosts << EOF
    192.168.44.146 k8smaster
    192.168.44.145 k8snode1
    192.168.44.144 k8snode2
    EOF
    # 在工作节点上修改/etc/hosts如下，默认的不用删除 只是在127.0.0.1上加了个设置的hostname
    [root@k8snode1 ~]# cat /etc/hosts
    127.0.0.1   localhost k8snode1 localhost4 localhost4.localdomain4
    ::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
    
    # 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  # 生效
    
    # 时间同步
    yum install ntpdate -y
    ntpdate time.windows.com

### 2 所有节点安装Docker/kubeadm/kubelet ###

# 安装docker
    $ wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
    $ yum -y install docker-ce-18.06.1.ce-3.el7
    $ systemctl enable docker && systemctl start docker
    $ docker --version
    Docker version 18.06.1-ce, build e68fc7a
    
    # 配置阿里云加速
     cat > /etc/docker/daemon.json << EOF
    {
      "registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
    }
    EOF
    
    # 添加阿里云yum软件源
    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kubenete
    yum install -y kubelet-1.18.0 kubeadm-1.18.0 kubectl-1.18.0
    systemctl enable kubelet

### 3 组建集群 ###

在master上进行集群初始化，apiserver-advertise-address为master节点ip，后面两个ip自定义 不可冲突
    
    kubeadm init \
      --apiserver-advertise-address=192.168.44.146 \
      --image-repository registry.aliyuncs.com/google_containers \
      --kubernetes-version v1.18.0 \
      --service-cidr=10.96.0.0/12 \
      --pod-network-cidr=10.244.0.0/16

执行完后输出：

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
    
    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 会输出ip:端口 --token fnd9sk.x9qkd9z5w2vho9u9 \
        --discovery-token-ca-cert-hash sha256:0241bb2123277ecce6a15024152e862078cc47c3c778cb0ac7447741ae2f4d70

在master上执行日志中的：

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

此时查看集群的节点，只有一个master

kubectl get nodes

在从节点上执行，日志输出的部分 kubeadm join部分，在执行前telnet下和日志输出的ip 端口通不通，不通的话很可能是master节点上防火墙围观吧，需按上面介绍的关闭。

kubeadm join 会输出ip:端口 --token fnd9sk.x9qkd9z5w2vho9u9 \
        --discovery-token-ca-cert-hash sha256:0241bb2123277ecce6a15024152e862078cc47c3c778cb0ac7447741ae2f4d70

等待执行完，没有报错，使用kubectl get nodes查看节点，成功后另外一个节点也是按这个过程加入。

# 此时kubectl查看节点状态是NoteReady，需要在Master节点进行安装CNI网络插件让集群进入Ready状态
    [root@k8smaster ~]# kubectl get nodes
    NAME        STATUS     ROLES    AGE     VERSION
    k8smaster   NotReady   master   68m     v1.18.0
    k8snode1    NotReady   <none>   4m46s   v1.18.0
    k8snode2    NotReady   <none>   10m     v1.18.0
    
    # 在Master节点执行安装CNI网络插件
    kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
    
    # 执行如下命令，发现pods都变为running状态说明CNI网络插件安装成功
    kubectl get pods -n kube-system
    
    #此时查看集群节点状态变为了Ready
    [root@k8smaster ~]# kubectl get nodes
    NAME        STATUS   ROLES    AGE   VERSION
    k8smaster   Ready    master   77m   v1.18.0
    k8snode1    Ready    <none>   13m   v1.18.0
    k8snode2    Ready    <none>   18m   v1.18.0

集群安装成功，部署Nginx

# 当前没有运行的pod
    [root@k8smaster ~]# kubectl get pod
    NAME                    READY   STATUS              RESTARTS   AGE
    
    # 创建一个nginx服务
    
    kubectl create deployment nginx --image=nginx
    
    [root@k8smaster ~]# kubectl expose deployment nginx --port=80 --type=NodePort
    service/nginx exposed
    
    # 查看pod状态是容器创建过程中，需要等待变为Running状态
    [root@k8smaster ~]# kubectl get pod
    NAME                    READY   STATUS              RESTARTS   AGE
    nginx-f89759699-dbpnp   0/1     ContainerCreating   0          9s
    
    # 对nginx服务暴露端口
    [root@k8smaster ~]# kubectl expose deployment nginx --port=80 --type=NodePort
    service/nginx exposed
    
    # 查看pod更多信息
    root@k8smaster ~]# kubectl get pod,svc
    NAME                        READY   STATUS    RESTARTS   AGE
    pod/nginx-f89759699-dbpnp   1/1     Running   0          3m29s
    
    NAME                 TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
    service/kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP        95m
    service/nginx        NodePort    10.104.121.235   <none>        80:32052/TCP   53s

使用三个集群节点的任意一个IP加映射的端口测试访问Nginx都可以访问成功，Nginx部署成功。