mirror of
https://github.com/yeasy/docker_practice.git
synced 2024-11-16 11:33:40 +00:00
188 lines
5.3 KiB
Go
188 lines
5.3 KiB
Go
# 使用 kubeadm 部署 kubernetes
|
||
|
||
`kubeadm` 提供了 `kubeadm init` 以及 `kubeadm join` 这两个命令作为快速创建 `kubernetes` 集群的最佳实践。
|
||
|
||
## 安装 Docker
|
||
|
||
参考 [安装 Docker](../../install) 一节安装 Docker。
|
||
|
||
## 安装 **kubelet** **kubeadm** **kubectl**
|
||
|
||
### Ubuntu/Debian
|
||
|
||
```bash
|
||
$ apt-get update && apt-get install -y apt-transport-https
|
||
$ curl https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | apt-key add -
|
||
|
||
$ cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list
|
||
deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main
|
||
EOF
|
||
|
||
$ apt-get update
|
||
$ apt-get install -y kubelet kubeadm kubectl
|
||
```
|
||
|
||
### CentOS/Fedora
|
||
|
||
```bash
|
||
$ cat <<EOF | sudo tee /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
|
||
|
||
$ sudo yum install -y kubelet kubeadm kubectl
|
||
```
|
||
|
||
## 修改内核的运行参数
|
||
|
||
```bash
|
||
$ cat <<EOF | sudo tee /etc/sysctl.d/99-kubernetes-cri.conf
|
||
net.bridge.bridge-nf-call-iptables = 1
|
||
net.ipv4.ip_forward = 1
|
||
net.bridge.bridge-nf-call-ip6tables = 1
|
||
EOF
|
||
|
||
# 应用配置
|
||
$ sysctl --system
|
||
```
|
||
|
||
## 配置 kubelet
|
||
|
||
### 修改 `kubelet.service`
|
||
|
||
`/etc/systemd/system/kubelet.service.d/10-proxy-ipvs.conf` 写入以下内容
|
||
|
||
```bash
|
||
# 启用 ipvs 相关内核模块
|
||
[Service]
|
||
ExecStartPre=-/sbin/modprobe ip_vs
|
||
ExecStartPre=-/sbin/modprobe ip_vs_rr
|
||
ExecStartPre=-/sbin/modprobe ip_vs_wrr
|
||
ExecStartPre=-/sbin/modprobe ip_vs_sh
|
||
```
|
||
|
||
执行以下命令应用配置。
|
||
|
||
```bash
|
||
$ sudo systemctl daemon-reload
|
||
```
|
||
|
||
## 部署
|
||
|
||
### master
|
||
|
||
```bash
|
||
$ sudo kubeadm init --image-repository registry.cn-hangzhou.aliyuncs.com/google_containers \
|
||
--pod-network-cidr 10.244.0.0/16 \
|
||
--v 5 \
|
||
--ignore-preflight-errors=all
|
||
```
|
||
|
||
* `--pod-network-cidr 10.244.0.0/16` 参数与后续 CNI 插件有关，这里以 `flannel` 为例，若后续部署其他类型的网络插件请更改此参数。
|
||
|
||
> 执行可能出现错误，例如缺少依赖包，根据提示安装即可。
|
||
|
||
执行成功会输出
|
||
|
||
```bash
|
||
...
|
||
[addons] Applied essential addon: CoreDNS
|
||
I1116 12:35:13.270407 86677 request.go:538] Throttling request took 181.409184ms, request: POST:https://192.168.199.100:6443/api/v1/namespaces/kube-system/serviceaccounts
|
||
I1116 12:35:13.470292 86677 request.go:538] Throttling request took 186.088112ms, request: POST:https://192.168.199.100:6443/api/v1/namespaces/kube-system/configmaps
|
||
[addons] Applied essential addon: kube-proxy
|
||
|
||
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 192.168.199.100:6443 --token cz81zt.orsy9gm9v649e5lf \
|
||
--discovery-token-ca-cert-hash sha256:5edb316fd0d8ea2792cba15cdf1c899a366f147aa03cba52d4e5c5884ad836fe
|
||
```
|
||
|
||
### node 工作节点
|
||
|
||
在 **另一主机** 重复 **部署** 小节以前的步骤，安装配置好 kubelet。根据提示，加入到集群。
|
||
|
||
```bash
|
||
$ kubeadm join 192.168.199.100:6443 --token cz81zt.orsy9gm9v649e5lf \
|
||
--discovery-token-ca-cert-hash sha256:5edb316fd0d8ea2792cba15cdf1c899a366f147aa03cba52d4e5c5884ad836fe
|
||
```
|
||
|
||
## 查看服务
|
||
|
||
所有服务启动后，查看本地实际运行的 Docker 容器。这些服务大概分为三类：主节点服务、工作节点服务和其它服务。
|
||
|
||
### 主节点服务
|
||
|
||
* `apiserver` 是整个系统的对外接口，提供 RESTful 方式供客户端和其它组件调用；
|
||
|
||
* `scheduler` 负责对资源进行调度，分配某个 pod 到某个节点上；
|
||
|
||
* `controller-manager` 负责管理控制器，包括 endpoint-controller（刷新服务和 pod 的关联信息）和 replication-controller（维护某个 pod 的复制为配置的数值）。
|
||
|
||
### 工作节点服务
|
||
|
||
* `proxy` 为 pod 上的服务提供访问的代理。
|
||
|
||
### 其它服务
|
||
|
||
* Etcd 是所有状态的存储数据库；
|
||
|
||
## 使用
|
||
|
||
将 `/etc/kubernetes/admin.conf` 复制到 `~/.kube/config`
|
||
|
||
执行 `$ kubectl get all -A` 查看启动的服务。
|
||
|
||
由于未部署 CNI 插件，CoreDNS 未正常启动。如何使用 Kubernetes，请参考后续章节。
|
||
|
||
## 部署 CNI
|
||
|
||
这里以 `flannel` 为例进行介绍。
|
||
|
||
### flannel
|
||
|
||
检查 podCIDR 设置
|
||
|
||
```bash
|
||
$ kubectl get node -o yaml | grep CIDR
|
||
|
||
# 输出
|
||
podCIDR: 10.244.0.0/24
|
||
podCIDRs:
|
||
```
|
||
|
||
```bash
|
||
$ kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/v0.11.0/Documentation/kube-flannel.yml
|
||
```
|
||
|
||
## master 节点默认不能运行 pod
|
||
|
||
如果用 `kubeadm` 部署一个单节点集群，默认情况下无法使用，请执行以下命令解除限制
|
||
|
||
```bash
|
||
$ kubectl taint nodes --all node-role.kubernetes.io/master-
|
||
|
||
# 恢复默认值
|
||
# $ kubectl taint nodes NODE_NAME node-role.kubernetes.io/master=true:NoSchedule
|
||
```
|
||
|
||
## 参考文档
|
||
|
||
* [官方文档](https://kubernetes.io/zh/docs/setup/independent/create-cluster-kubeadm/)
|