kubeadm中怎么搭建k8s集群

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一、环境准备：

两台Centos7主机，166(master)167(node01)，两台机都安装docker，以下操作在两台机上都执行。

修改/etc/hosts文件内容

[zjin@master ~]$ cat /etc/hosts10.3.4.166 master10.3.4.167 node01

禁用防火墙

[zjin@master ~]$ sudo systemctl stop firewalld[zjin@master ~]$ sudo systemctl disable firewalld

关闭selinux

cat /etc/selinux/configSELINUX=disabled

创建/etc/sysctl.d/k8s.conf文件

net.bridge.bridge-nf-call-ip6tables = 1net.bridge.bridge-nf-call-iptables = 1net.ipv4.ip_forward = 1

再执行如下命令：

[zjin@master ~]$ sudo modprobe br_netfilter[zjin@master ~]$ sudo sysctl -p /etc/sysctl.d/k8s.confnet.bridge.bridge-nf-call-ip6tables = 1net.bridge.bridge-nf-call-iptables = 1net.ipv4.ip_forward = 1

二、拉取镜像：

在master上：

docker pull akipa11/kube-apiserver-amd64:v1.10.0docker pull akipa11/kube-scheduler-amd64:v1.10.0docker pull akipa11/kube-controller-manager-amd64:v1.10.0docker pull akipa11/kube-proxy-amd64:v1.10.0docker pull akipa11/k8s-dns-kube-dns-amd64:1.14.8docker pull akipa11/k8s-dns-dnsmasq-nanny-amd64:1.14.8docker pull akipa11/k8s-dns-sidecar-amd64:1.14.8docker pull akipa11/etcd-amd64:3.1.12docker pull akipa11/flannel:v0.10.0-amd64docker pull akipa11/pause-amd64:3.1docker tag akipa11/kube-apiserver-amd64:v1.10.0 k8s.gcr.io/kube-apiserver-amd64:v1.10.0docker tag akipa11/kube-scheduler-amd64:v1.10.0 k8s.gcr.io/kube-scheduler-amd64:v1.10.0docker tag akipa11/kube-controller-manager-amd64:v1.10.0 k8s.gcr.io/kube-controller-manager-amd64:v1.10.0docker tag akipa11/kube-proxy-amd64:v1.10.0 k8s.gcr.io/kube-proxy-amd64:v1.10.0docker tag akipa11/k8s-dns-kube-dns-amd64:1.14.8 k8s.gcr.io/k8s-dns-kube-dns-amd64:1.14.8docker tag akipa11/k8s-dns-dnsmasq-nanny-amd64:1.14.8 k8s.gcr.io/k8s-dns-dnsmasq-nanny-amd64:1.14.8docker tag akipa11/k8s-dns-sidecar-amd64:1.14.8 k8s.gcr.io/k8s-dns-sidecar-amd64:1.14.8docker tag akipa11/etcd-amd64:3.1.12 k8s.gcr.io/etcd-amd64:3.1.12docker tag akipa11/flannel:v0.10.0-amd64 quay.io/coreos/flannel:v0.10.0-amd64docker tag akipa11/pause-amd64:3.1 k8s.gcr.io/pause-amd64:3.1

node01上：

docker pull akipa11/kube-proxy-amd64:v1.10.0docker pull akipa11/flannel:v0.10.0-amd64docker pull akipa11/pause-amd64:3.1docker pull akipa11/kubernetes-dashboard-amd64:v1.8.3docker pull akipa11/heapster-influxdb-amd64:v1.3.3docker pull akipa11/heapster-grafana-amd64:v4.4.3docker pull akipa11/heapster-amd64:v1.4.2docker pull akipa11/k8s-dns-kube-dns-amd64:1.14.8docker pull akipa11/k8s-dns-dnsmasq-nanny-amd64:1.14.8docker pull akipa11/k8s-dns-sidecar-amd64:1.14.8docker tag akipa11/flannel:v0.10.0-amd64 quay.io/coreos/flannel:v0.10.0-amd64docker tag akipa11/pause-amd64:3.1 k8s.gcr.io/pause-amd64:3.1docker tag akipa11/kube-proxy-amd64:v1.10.0 k8s.gcr.io/kube-proxy-amd64:v1.10.0docker tag akipa11/k8s-dns-kube-dns-amd64:1.14.8 k8s.gcr.io/k8s-dns-kube-dns-amd64:1.14.8docker tag akipa11/k8s-dns-dnsmasq-nanny-amd64:1.14.8 k8s.gcr.io/k8s-dns-dnsmasq-nanny-amd64:1.14.8docker tag akipa11/k8s-dns-sidecar-amd64:1.14.8 k8s.gcr.io/k8s-dns-sidecar-amd64:1.14.8docker tag akipa11/kubernetes-dashboard-amd64:v1.8.3 k8s.gcr.io/kubernetes-dashboard-amd64:v1.8.3docker tag akipa11/heapster-influxdb-amd64:v1.3.3 k8s.gcr.io/heapster-influxdb-amd64:v1.3.3docker tag akipa11/heapster-grafana-amd64:v4.4.3 k8s.gcr.io/heapster-grafana-amd64:v4.4.3docker tag akipa11/heapster-amd64:v1.4.2 k8s.gcr.io/heapster-amd64:v1.4.2

三、安装kubeadm、kubelet、kubectl

1、配置yum源：

cat < /etc/yum.repos.d/kubernetes.repo[kubernetes]name=Kubernetesbaseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64enabled=1gpgcheck=0repo_gpgcheck=0gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg        http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpgEOF

2、安装kubeadm、kubelet、kubectl

此处我们安装的版本均为1.10.0-0

$ yum makecache fast $ yum install -y kubelet-1.10.0-0$ yum install -y kubectl-1.10.0-0$ yum install -y kubeadm-1.10.0-0

3、配置kubelet

• 修改cgroup-driver的参数

  修改文件 kubelet 的配置文件/etc/systemd/system/kubelet.service.d/10-kubeadm.conf，将其中的KUBELET_CGROUP_ARGS参数更改成cgroupfs

• 增加swap的配置参数

  在ExecStart之前，增加以下内容：

  Environment="KUBELET_EXTRA_ARGS=--fail-swap-on=false"

  
  

最后再重新加载配置文件

systemctl daemon-reload

四、集群安装初始化

在master上执行以下命令：

[zjin@master ~]$ sudo kubeadm init \> --kubernetes-version=v1.10.0 \> --pod-network-cidr=10.244.0.0/16 \> --apiserver-advertise-address=10.3.4.166 \> --ignore-preflight-errors=Swap

集群初始化的命令：kubeadm init，后面的参数是需要安装的集群版本，因为我们这里选择flannel作为 Pod 的网络插件，所以需要指定-pod-network-cidr=10.244.0.0/16，然后是 apiserver 的通信地址，这里就是我们 master 节点的 IP 地址，-ignore-preflight-errors=Swap表示忽略 swap 的错误提示信息。

最后，我们可以看到集群安装成功的信息：

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/configYou 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 nodeas root:  kubeadm join 10.3.4.166:6443 --token b9ftqo.6a3igsfxq96b1dt6 --discovery-token-ca-cert-hash sha256:d4517be6c40e40e1bbc749b24b35c0a7f68c0f75c1380c32b24d1ccb42e0decc

输入以下命令来配置使用kubectl访问集群：

[zjin@master ~]$ sudo mkdir -p $HOME/.kube[zjin@master ~]$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config[zjin@master ~]$ sudo chown $(id -u):$(id -g) $HOME/.kube/config

配置好kubectl之后，我们就可以使用kubectl来查看集群的相关信息了：

[zjin@master ~]$ kubectl get csNAME                 STATUS    MESSAGE              ERRORcontroller-manager   Healthy   ok                   scheduler            Healthy   ok                   etcd-0               Healthy   {"health": "true"}   [zjin@master ~]$ kubectl get csrNAME        AGE       REQUESTOR            CONDITIONcsr-nff2l   6m        system:node:master   Approved,Issued

如果在集群安装过程中遇到了错误，可以使用下面的命令来进行重置：

$ kubeadm reset$ ifconfig cni0 down && ip link delete cni0$ ifconfig flannel.1 down && ip link delete flannel.1$ rm -rf /var/lib/cni/

五、安装pod network

此处我们安装的是flannel网络插件。

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

注意，此处文件内容的inage版本号要修改为v0.10.0

[zjin@master ~]$ kubectl apply -f kube-flannel.yml podsecuritypolicy.policy "psp.flannel.unprivileged" createdclusterrole.rbac.authorization.k8s.io "flannel" createdclusterrolebinding.rbac.authorization.k8s.io "flannel" createdserviceaccount "flannel" createdconfigmap "kube-flannel-cfg" createddaemonset.apps "kube-flannel-ds-amd64" createddaemonset.apps "kube-flannel-ds-arm64" createddaemonset.apps "kube-flannel-ds-arm" createddaemonset.apps "kube-flannel-ds-ppc64le" createddaemonset.apps "kube-flannel-ds-s390x" created

安装完成后，我们可以使用kubectl get pods命令来查看集群中各组件的运行状态：

[zjin@master ~]$ kubectl get pods --all-namespacesNAMESPACE     NAME                             READY     STATUS    RESTARTS   AGEkube-system   etcd-master                      1/1       Running   0          40skube-system   kube-apiserver-master            1/1       Running   0          40skube-system   kube-controller-manager-master   1/1       Running   0          40skube-system   kube-dns-86f4d74b45-4vbx5        3/3       Running   0          12mkube-system   kube-flannel-ds-amd64-wskq5      1/1       Running   0          52skube-system   kube-proxy-7dk2l                 1/1       Running   0          12mkube-system   kube-scheduler-master            1/1       Running   0          40s

可以看到，全部都是Running状态。

六、添加节点

node01(167)上安装版本号一致的docker、kubeadm、kubelet、kubectl，然后执行以下命令：

[zjin@node01 ~]$ sudo kubeadm join 10.3.4.166:6443 --token ebimj5.91xj7atpxbke4x        yz --discovery-token-ca-cert-hash sha256:1eda2afcd5711343714ec2d2b6c6ea73ec06737        ee350b229d5b2eebfd82fb58a --ignore-preflight-errors=Swap

如果报错：

[preflight] Some fatal errors occurred:        [ERROR CRI]: unable to check if the container runtime at "/var/run/docke        rshim.sock" is running: fork/exec /bin/crictl -r /var/run/dockershim.sock info:         no such file or directory

这个是cri-tools版本造成的错误，可以卸载掉cri-tools即可解决。

yum remove cri-tools

再执行加入节点的命令：

[zjin@node01 ~]$ sudo kubeadm join 10.3.4.166:6443 --token ebimj5.91xj7atpxbke4x        yz --discovery-token-ca-cert-hash sha256:1eda2afcd5711343714ec2d2b6c6ea73ec06737        ee350b229d5b2eebfd82fb58a --ignore-preflight-errors=Swap[preflight] Running pre-flight checks.        [WARNING SystemVerification]: docker version is greater than the most re        cently validated version. Docker version: 18.03.0-ce. Max validated version: 17.        03        [WARNING FileExisting-crictl]: crictl not found in system pathSuggestion: go get github.com/kubernetes-incubator/cri-tools/cmd/crictl[discovery] Trying to connect to API Server "10.3.4.166:6443"[discovery] Created cluster-info discovery client, requesting info from "https:/        /10.3.4.166:6443"[discovery] Requesting info from "https://10.3.4.166:6443" again to validate TLS         against the pinned public key[discovery] Cluster info signature and contents are valid and TLS certificate va        lidates against pinned roots, will use API Server "10.3.4.166:6443"[discovery] Successfully established connection with API Server "10.3.4.166:6443        "This node has joined the cluster:* Certificate signing request was sent to master and a response  was received.* The Kubelet was informed of the new secure connection details.Run 'kubectl get nodes' on the master to see this node join the cluster.

然后把 master 节点的~/.kube/config文件拷贝到当前节点对应的位置即可使用 kubectl 命令行工具了。

[zjin@master ~]$ kubectl get nodesNAME      STATUS    ROLES     AGE       VERSIONmaster    Ready     master    47m       v1.10.0node01    Ready         3m        v1.10.0

以上就是kubeadm中怎么搭建k8s集群，小编相信有部分知识点可能是我们日常工作会见到或用到的。希望你能通过这篇文章学到更多知识。更多详情敬请关注行业资讯频道。