使用Kubeadm在CentOS7.2上部署Kubernetes集群的方法

本文参考kubernetes官网文章Installing Kubernetes on Linux with kubeadm在CentOS7.2使用Kubeadm部署Kuebernetes集群,解决了一些在按照该文档部署时遇到的问题。

操作系统版本

  # cat /etc/redhat-release   CentOS Linux release 7.2.1511 (Core)

内核版本

  # uname -r  3.10.0-327.el7.x86_64

集群节点

  192.168.120.122 kube-master  192.168.120.123 kube-agent1  192.168.120.124 kube-agent2  192.168.120.125 kube-agent3

即该集群包含一个控制节点和三个工作节点。

部署前的准备

配置可以访问google相关网站

这种部署方式使用的软件包由google相关源提供,因此集群节点必须能够访问外网,至于如何配置请自行解决。

关闭防火墙

  # systemctl stop firewalld.service && systemctl disable firewalld.service

禁用SELinux

  # setenforce 0  # sed -i.bak 's/SELINUX=enforcing/SELINUX=permissive/' /etc/selinux/config

配置yum源

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

安装kubelet和kubeadm

在所有节点上安装以下软件包:

  # yum install -y docker kubelet kubeadm kubectl kubernetes-cni  # systemctl enable docker && systemctl start docker  # systemctl enable kubelet && systemctl start kubelet

然后设置内核参数:

  # sysctl net.bridge.bridge-nf-call-iptables=1  # sysctl net.bridge.bridge-nf-call-ip6tables=1

初始化控制节点

  # kubeadm init --pod-network-cidr=10.244.0.0/16

因为在该集群中将使用flannel搭建pod网络,因此必须添加Cpod-network-cidr参数。

注意:初始化较慢,因为该过程会pull一些docker image。

该命令的输出如下:

  Initializing your master...  [kubeadm] WARNING: kubeadm is in beta, please do not use it for production clusters.  [init] Using Kubernetes version: v1.6.4  [init] Using Authorization mode: RBAC  [preflight] Running pre-flight checks  [certificates] Generated CA certificate and key.  [certificates] Generated API server certificate and key.  [certificates] API Server serving cert is signed for DNS names [kube-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.120.122]  [certificates] Generated API server kubelet client certificate and key.  [certificates] Generated service account token signing key and public key.  [certificates] Generated front-proxy CA certificate and key.  [certificates] Generated front-proxy client certificate and key.  [certificates] Valid certificates and keys now exist in "/etc/kubernetes/pki"  [kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/admin.conf"  [kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"  [kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/controller-manager.conf"  [kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/scheduler.conf"  [apiclient] Created API client, waiting for the control plane to become ready  [apiclient] All control plane components are healthy after 1377.560339 seconds  [apiclient] Waiting for at least one node to register  [apiclient] First node has registered after 6.039626 seconds  [token] Using token: 60bc68.e94800f3c5c4c2d5  [apiconfig] Created RBAC rules  [addons] Created essential addon: kube-proxy  [addons] Created essential addon: kube-dns    Your Kubernetes master has initialized successfully!    To start using your cluster, you need to run (as a regular user):     sudo cp /etc/kubernetes/admin.conf $HOME/   sudo chown $(id -u):$(id -g) $HOME/admin.conf   export KUBECONFIG=$HOME/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: http://kubernetes.io/docs/admin/addons/    You can now join any number of machines by running the following on each node as root:     kubeadm join --token <token> 192.168.120.122:6443  

观察控制节点的docker image:

  # docker images  REPOSITORY                        TAG         IMAGE ID      CREATED       SIZE  gcr.io/google_containers/kube-apiserver-amd64      v1.6.4       4e3810a19a64    2 days ago     150.6 MB  gcr.io/google_containers/kube-controller-manager-amd64  v1.6.4       0ea16a85ac34    2 days ago     132.8 MB  gcr.io/google_containers/kube-proxy-amd64        v1.6.4       e073a55c288b    2 days ago     109.2 MB  gcr.io/google_containers/kube-scheduler-amd64      v1.6.4       1fab9be555e1    2 days ago     76.75 MB  gcr.io/google_containers/etcd-amd64           3.0.17       243830dae7dd    12 weeks ago    168.9 MB  gcr.io/google_containers/pause-amd64           3.0         99e59f495ffa    12 months ago    746.9 kB

按照初始化命令的提示执行以下操作:

  # cp /etc/kubernetes/admin.conf $HOME/  # chown $(id -u):$(id -g) $HOME/admin.conf  # export KUBECONFIG=$HOME/admin.conf

隔离控制节点

  # kubectl taint nodes --all node-role.kubernetes.io/master-  node "kube-master" tainted

安装pod网络

  # kubectl apply -f flannel/Documentation/kube-flannel-rbac.yml  clusterrole "flannel" created  clusterrolebinding "flannel" created    # kubectl apply -f flannel/Documentation/kube-flannel.yml  serviceaccount "flannel" created  configmap "kube-flannel-cfg" created  daemonset "kube-flannel-ds" created  

可以通过git clone flannel仓库:

  # git clone https://github.com/coreos/flannel.git

添加工作节点

  # kubeadm join --token <token> 192.168.120.122:6443

该操作输出如下:

  [kubeadm] WARNING: kubeadm is in beta, please do not use it for production clusters.  [preflight] Running pre-flight checks  [discovery] Trying to connect to API Server "192.168.120.122:6443"  [discovery] Created cluster-info discovery client, requesting info from "https://192.168.120.122:6443"  [discovery] Cluster info signature and contents are valid, will use API Server "https://192.168.120.122:6443"  [discovery] Successfully established connection with API Server "192.168.120.122:6443"  [bootstrap] Detected server version: v1.6.4  [bootstrap] The server supports the Certificates API (certificates.k8s.io/v1beta1)  [csr] Created API client to obtain unique certificate for this node, generating keys and certificate signing request  [csr] Received signed certificate from the API server, generating KubeConfig...  [kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"    Node join complete:  * Certificate signing request sent to master and response   received.  * Kubelet informed of new secure connection details.    Run 'kubectl get nodes' on the master to see this machine join.  

在控制节点观察集群状态

  # kubectl get nodes  NAME     STATUS  AGE    VERSION  kube-agent1  Ready   16m    v1.6.3  kube-agent2  Ready   16m    v1.6.3  kube-agent3  Ready   16m    v1.6.3  kube-master  Ready   37m    v1.6.3    # kubectl get pods --all-namespaces -o wide  NAMESPACE   NAME                 READY   STATUS  RESTARTS  AGE    IP        NODE  kube-system  etcd-kube-master           1/1    Running  0     32m    192.168.120.122  kube-master  kube-system  kube-apiserver-kube-master      1/1    Running  7     32m    192.168.120.122  kube-master  kube-system  kube-controller-manager-kube-master  1/1    Running  0     32m    192.168.120.122  kube-master  kube-system  kube-dns-3913472980-3x9wh       3/3    Running  0     37m    10.244.0.2    kube-master  kube-system  kube-flannel-ds-1m4wz         2/2    Running  0     18m    192.168.120.122  kube-master  kube-system  kube-flannel-ds-3jwf5         2/2    Running  0     17m    192.168.120.123  kube-agent1  kube-system  kube-flannel-ds-41qbs         2/2    Running  4     17m    192.168.120.125  kube-agent3  kube-system  kube-flannel-ds-ssjct         2/2    Running  4     17m    192.168.120.124  kube-agent2  kube-system  kube-proxy-0mmfc           1/1    Running  0     17m    192.168.120.124  kube-agent2  kube-system  kube-proxy-23vwr           1/1    Running  0     17m    192.168.120.125  kube-agent3  kube-system  kube-proxy-5q8vq           1/1    Running  0     17m    192.168.120.123  kube-agent1  kube-system  kube-proxy-8srwn           1/1    Running  0     37m    192.168.120.122  kube-master  kube-system  kube-scheduler-kube-master      1/1    Running  0     32m    192.168.120.122  kube-master  

至此,完成Kubernetes集群的部署。

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。

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