搭建Kubernetes容器集群平台
文章目录
- 官方提供Kubernetes部署3种方式
- 1. 安装要求
- 2. 准备环境
- 3. 安装Docker
- 4. 安装kubeadm，kubelet和kubectl
-
- 4.1 添加阿里云YUM软件源
- 4.2 安装kubeadm，kubelet和kubectl
- 5. 使用kubeadm创建单个Master集群
-
- 5.1 默认下载镜像地址在国外无法访问，先从准备好所需镜像
- 5.2 初始化Master
- 5.3 安装Pod网络 - 插件
- 5.4 加入工作节点
- 6. kubernetes dashboard
- 总结
官方提供Kubernetes部署3种方式
- minikube
Minikube是一个工具，可以在本地快速运行一个单点的Kubernetes，尝试Kubernetes或日常开发的用户使用。不能用于生产环境。
官方文档：https://kubernetes.io/docs/setup/minikube/
- kubeadm
kubeadm可帮助你快速部署一套kubernetes集群。kubeadm设计目的为新用户开始尝试kubernetes提供一种简单的方法。目前是Beta版。
官方文档：
https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm/
https://kubernetes.io/docs/setup/independent/install-kubeadm/
- 二进制包
从官方下载发行版的二进制包，手动部署每个组件，组成Kubernetes集群。目前企业生产环境中主要使用该方式。
下载地址：https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.11.md#v1113
提示：以下是本篇文章正文内容，下面案例可供参考
1. 安装要求
- 操作系统
- Ubuntu 16.04+
- Debian 9
- CentOS 7
- RHEL 7
- Fedora 25/26 (best-effort)
- 其他
- 内存2GB + ，2核CPU +
- 集群节点之间可以通信
- 每个节点唯一主机名，MAC地址和product_uuid
- 检查MAC地址：使用ip link或者ifconfig -a
- 检查product_uuid：cat /sys/class/dmi/id/product_uuid
- 禁止swap分区。这样才能使kubelet正常工作
2. 准备环境
命令如下（示例）：
关闭防火墙：
# systemctl stop firewalld
# systemctl disable firewalld
关闭selinux：
# sed -i 's/enforcing/disabled/' /etc/selinux/config
# setenforce 0
关闭swap：
# swapoff -a # 临时
# vim /etc/fstab # 永久
添加主机名与IP对应关系：
# cat /etc/hosts
192.168.0.11 k8s-master
192.168.0.12 k8s-node1
192.168.0.13 k8s-node2
同步时间：
# yum install ntpdate -y
# ntpdate ntp.api.bz
3. 安装Docker
Docker与Kubernetes关系图：
命令如下（示例）：
# 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 docker-ce-17.03.3.ce -y #目前kubeadm最大支持docker-ce-17.03，所以要指定该版本安装
# systemctl enable docker && systemctl start docker
如果提示container-selinux依赖问题，先安装ce-17.03匹配版本：
# yum localinstall https://download.docker.com/linux/centos/7/x86_64/stable/Packages/docker-ce-selinux-17.03.3.ce-1.el7.noarch.rpm
4. 安装kubeadm，kubelet和kubectl
- kubeadm： 引导集群的命令
- kubelet：集群中运行任务的代理程序
- kubectl：命令行管理工具
4.1 添加阿里云YUM软件源
# 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
4.2 安装kubeadm，kubelet和kubectl
# yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
# systemctl enable kubelet && systemctl start kubelet
注意：使用Docker时，kubeadm会自动检查kubelet的cgroup驱动程序，并/var/lib/kubelet/kubeadm-flags.env在运行时将其设置在文件中。如果使用的其他CRI，则必须在/etc/default/kubelet中cgroup-driver值修改为cgroupfs：
# cat /var/lib/kubelet/kubeadm-flags.env
KUBELET_KUBEADM_ARGS=--cgroup-driver=cgroupfs --cni-bin-dir=/opt/cni/bin --cni-conf-dir=/etc/cni/net.d --network-plugin=cni
# systemctl daemon-reload
# systemctl restart kubelet
5. 使用kubeadm创建单个Master集群
5.1 默认下载镜像地址在国外无法访问，先从准备好所需镜像
保存到脚本之间运行：
K8S_VERSION=v1.11.2
ETCD_VERSION=3.2.18
DASHBOARD_VERSION=v1.8.3
FLANNEL_VERSION=v0.10.0-amd64
DNS_VERSION=1.1.3
PAUSE_VERSION=3.1
# 基本组件
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver-amd64:$K8S_VERSION
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager-amd64:$K8S_VERSION
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler-amd64:$K8S_VERSION
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy-amd64:$K8S_VERSION
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/etcd-amd64:$ETCD_VERSION
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/pause:$PAUSE_VERSION
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:$DNS_VERSION
# 网络组件
docker pull quay.io/coreos/flannel:$FLANNEL_VERSION
# 修改tag
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver-amd64:$K8S_VERSION k8s.gcr.io/kube-apiserver-amd64:$K8S_VERSION
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager-amd64:$K8S_VERSION k8s.gcr.io/kube-controller-manager-amd64:$K8S_VERSION
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler-amd64:$K8S_VERSION k8s.gcr.io/kube-scheduler-amd64:$K8S_VERSION
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy-amd64:$K8S_VERSION k8s.gcr.io/kube-proxy-amd64:$K8S_VERSION
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/etcd-amd64:$ETCD_VERSION k8s.gcr.io/etcd-amd64:$ETCD_VERSION
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause:$PAUSE_VERSION k8s.gcr.io/pause:$PAUSE_VERSION
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:$DNS_VERSION k8s.gcr.io/coredns:$DNS_VERSION
5.2 初始化Master
# kubeadm init --kubernetes-version=1.11.2 --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.0.11
...
Your Kubernetes master has initialized successfully!
To start using your cluster, you need to run (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 addon 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> <master-ip>:<master-port> --discovery-token-ca-cert-hash sha256:<hash>
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown ( i d − u ) : (id -u): (id−u):(id -g) $HOME/.kube/config
5.3 安装Pod网络 - 插件
# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/v0.10.0/Documentation/kube-flannel.yml
5.4 加入工作节点
在Node节点切换到root账号执行：
# kubeadm join 192.168.0.11:6443 --token 6hk68y.0rdz1wdjyh85ntkr --discovery-token-ca-cert-hash sha256:d1d3f59ae37fbd632707cbeb9b095d0d0b19af535078091993c4bc4d9d2a7782
格式：kubeadm join --token : --discovery-token-ca-cert-hash sha256:
6. kubernetes dashboard
先将yaml文件下载下来，修改里面镜像地址和Service NodePort类型。
# wget https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/recommended/kubernetes-dashboard.yaml
修改镜像地址：
# registry.cn-hangzhou.aliyuncs.com/google_containers/kubernetes-dashboard-amd64:v1.10.0
修改Service：
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kube-system
spec:
type: NodePort
ports:
- port: 443
targetPort: 8443
nodePort: 30001
selector:
k8s-app: kubernetes-dashboard
# kubectl apply -f kubernetes-dashboard.yaml
创建一个管理员角色：
apiVersion: v1
kind: ServiceAccount
metadata:
name: dashboard-admin
namespace: kube-system
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: dashboard-admin
subjects:
- kind: ServiceAccount
name: dashboard-admin
namespace: kube-system
roleRef:
kind: ClusterRole
name: cluster-admin
apiGroup: rbac.authorization.k8s.io
# kubectl apply -f k8s-admin.yaml
使用上述创建账号的token登录Kubernetes Dashboard：
# kubectl get secret -n kube-system
# kubectl describe secret dashboard-admin-token-bwdjj -n kube-system
...
token: eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.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.0hQU5Di_P1OX1DcnW2AYzjDAED66EOrqhF5iupv39wvB8wE-aLRSQyp0twX2M8u1KMZ67n6LxbH17VwEQkMDRVXs7ZlUCyAAD6kHDz3k-f7PAzH5vcuyO4veQ9ooVjk3DKjrP4zXQChHllBB1wmD_oyLjoWxK3Z5MBTlVGzSixVwuQNpFPbuS6Z7iLGwUOgjI0cGZ9Tt6cXzcK81KfAEpDIP_CtFV_Jw4s98EgBex9mZh6vq1dcxr03qfuK--udd_8GWZctu_p_P15hZZLoKEm5GCbs6JGvKL2aao_DEHfLp3XYEnApojI91vU4qAqdkvMZ2qWQNGYv4KNi2yPOOJQ
总结
在2020/2021年Docker/Kubernetes容器技术无疑是业内最火的技术。根据招聘简介情况来看，容器技术已成为运维工程师、架构师必备技能。
为帮助大家快速掌握这门主流技术，少走弯路，提高核心竞争力。决定写《基于Kubernetes企业容器云平台落地与实践》文章专栏，给朋友在企业落地容器云平台提供一些企业实践性指导，希望自己所学所思的东西能够帮助到大家，能够有所启发。