RHEL / CentOS 7上的某些用户报告了由于iptables被绕过而导致流量被错误路由的问题。应该确保net.bridge.bridge-nf-call-iptables的sysctl配置中被设置为1，例如
cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system
安装kubelet kubeadm kubectl
[root@aniu-k8s ~]# yum install -y kubelet kubeadm kubectl
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.163.com
* epel: mirrors.tongji.edu.cn
*
extras: mirrors.163.com
* updates: mirrors.163.com
Package kubelet-1.9.2-0.x86_64 already installed and latest version
Package kubeadm-1.9.2-0.x86_64 already installed and latest version
Package kubectl-1.9.2-0.x86_64 already installed and latest version
Nothing to do
# systemctl enable kubelet && systemctl start kubelet
初始化kubeadm，否则启动kubelet报证书错误
[root@aniu-k8s ~]# kubeadm init --kubernetes-version=v1.9.2
[init] Using Kubernetes version: v1.9.2
[init] Using Authorization modes: [Node RBAC]
[preflight] Running pre-flight checks.
[WARNING FileExisting-crictl]: crictl not found in system path
[preflight] Starting the kubelet service
[certificates] Generated ca certificate and key.
[certificates] Generated apiserver certificate and key.
[certificates] apiserver serving cert is signed for DNS names [aniu-k8s kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.10.10]
[certificates] Generated apiserver-kubelet-client certificate and key.
[certificates] Generated sa 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: "admin.conf"
[kubeconfig] Wrote KubeConfig file to disk: "kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "controller-manager.conf"
[kubeconfig] Wrote KubeConfig file to disk: "scheduler.conf"
[controlplane] Wrote Static Pod manifest for component kube-apiserver to "/etc/kubernetes/manifests/kube-apiserver.yaml"
[controlplane] Wrote Static Pod manifest for component kube-controller-manager to "/etc/kubernetes/manifests/kube-controller-manager.yaml"
[controlplane] Wrote Static Pod manifest for component kube-scheduler to "/etc/kubernetes/manifests/kube-scheduler.yaml"
[etcd] Wrote Static Pod manifest for a local etcd instance to "/etc/kubernetes/manifests/etcd.yaml"
[init] Waiting for the kubelet to boot up the control plane as Static Pods from directory "/etc/kubernetes/manifests".
[init] This might take a minute or longer if the control plane images have to be pulled.
[apiclient] All control plane components are healthy after 75.502276 seconds
[uploadconfig] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[markmaster] Will mark node aniu-k8s as master by adding a label and a taint
[markmaster] Master aniu-k8s tainted and labelled with key/value: node-role.kubernetes.io/master=""
[bootstraptoken] Using token: d9b013.26c2f690632cbef9
[bootstraptoken] Configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstraptoken] Configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstraptoken] Configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstraptoken] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[addons] Applied essential addon: kube-dns
[addons] Applied essential addon: kube-proxy
Your Kubernetes master 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/
You can now join any number of machines by running the following on each node
as root:
kubeadm join --token d9b013.26c2f690632cbef9 192.168.10.10:6443 --discovery-token-ca-cert-hash sha256:887a2ea3fccca1dec2caa12ad2e54f5baf806f29becf548a3b098ee3a869b518
使用kubeadm创建群集
参考：https://kubernetes.io/docs/setup/independent/create-cluster-kubeadm/
kubeadm是一个工具包，可帮助您以简单，合理安全和可扩展的方式引导最佳实践Kubernetes群集。它还支持为您管理Bootstrap令牌并升级/降级群集。