# kubectl run curl --image=radial/busyboxplus:curl -it
kubectl run --generator=deployment/apps.v1beta1 is DEPRECATED and will be removed in a future version. Use kubectl create instead.
If you don't see a command prompt, try pressing enter.
[ root@curl-5cc7b478b6-r997p:/ ]$
注：在此过程中可能会出现curl容器一直处于pending状态，报错信息如下：
0/1 nodes are available: 1 node(s) had taints that the pod didn’t tolerate.
解决方法：
# kubectl taint nodes –all node-role.kubernetes.io/master-
进入后执行nslookup kubernetes.default确认解析正常:
$ nslookup kubernetes.default
Server: 10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local
Name: kubernetes.default
Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local
Node节点配置
安装docker的yum源:
# yum install -y yum-utils device-mapper-persistent-data lvm2
# yum-config-manager \
--add-repo \
https://download.docker.com/linux/centos/docker-ce.repo
# yum install -y --setopt=obsoletes=0 docker-ce
安装kubeadm和kubelet：
配置kubernetes.repo的源，由于官方源国内无法访问，这里使用阿里云yum源
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
测试地址https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64是否可用，如果不可用需要×××
# curl https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
# yum -y makecache fast
# yum install -y kubelet kubeadm kubectl
...
Installed:
kubeadm.x86_64 0:1.15.0-0 kubectl.x86_64 0:1.15.0-0 kubelet.x86_64 0:1.15.0-0
Dependency Installed:
conntrack-tools.x86_64 0:1.4.4-4.el7 cri-tools.x86_64 0:1.12.0-0 kubernetes-cni.x86_64 0:0.7.5-0 libnetfilter_cthelper.x86_64 0:1.0.0-9.el7
libnetfilter_cttimeout.x86_64 0:1.0.0-6.el7 libnetfilter_queue.x86_64 0:1.0.2-2.el7_2
# swapoff -a
修改 /etc/fstab 文件，注释掉 SWAP 的自动挂载，
# UUID=2d1e946c-f45d-4516-86cf-946bde9bdcd8 swap swap defaults 0 0
使用free -m确认swap已经关闭。 swappiness参数调整，修改/etc/sysctl.d/k8s.conf添加下面一行：
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
vm.swappiness=0
使修改生效
# sysctl -p /etc/sysctl.d/k8s.conf
下面将node1这个主机添加到Kubernetes集群中，在node1上执行:
# kubeadm join 192.168.1.21:6443 --token 4qcl2f.gtl3h8e5kjltuo0r \
--discovery-token-ca-cert-hash sha256:7ed5404175cc0bf18dbfe53f19d4a35b1e3d40c19b10924275868ebf2a3bbe6e \
--ignore-preflight-errors=Swap
[preflight] Running pre-flight checks
[WARNING Swap]: running with swap on is not supported. Please disable swap
[WARNING Service-Kubelet]: kubelet service is not enabled, please run 'systemctl enable kubelet.service'
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.15" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Activating the kubelet service
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...
This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the control-plane to see this node join the cluster.
node1加入集群很是顺利，下面在master节点上执行命令查看集群中的节点：